mcs/class/Managed.Windows.Forms/System.Windows.Forms/TextControl.cs

   1 // Permission is hereby granted, free of charge, to any person obtaining
   2 // a copy of this software and associated documentation files (the
   3 // "Software"), to deal in the Software without restriction, including
   4 // without limitation the rights to use, copy, modify, merge, publish,
   5 // distribute, sublicense, and/or sell copies of the Software, and to
   6 // permit persons to whom the Software is furnished to do so, subject to
   7 // the following conditions:
   8 //
   9 // The above copyright notice and this permission notice shall be
  10 // included in all copies or substantial portions of the Software.
  11 //
  12 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  13 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  14 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  15 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  16 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  17 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  18 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  19 //
  20 // Copyright (c) 2004-2006 Novell, Inc. (http://www.novell.com)
  21 //
  22 // Authors:
  23 //      Peter Bartok    pbartok@novell.com
  24 //
  25 //
  26
  27 // NOT COMPLETE
  28
  29 // There's still plenty of things missing, I've got most of it planned, just hadn't had
  30 // the time to write it all yet.
  31 // Stuff missing (in no particular order):
  32 // - Align text after RecalculateLine
  33 // - Implement tag types for hotlinks, etc.
  34 // - Implement CaretPgUp/PgDown
  35
  36 // NOTE:
  37 // selection_start.pos and selection_end.pos are 0-based
  38 // selection_start.pos = first selected char
  39 // selection_end.pos = first NOT-selected char
  40 //
  41 // FormatText methods are 1-based (as are all tags, LineTag.Start is 1 for
  42 // the first character on a line; the reason is that 0 is the position
  43 // *before* the first character on a line
  44
  45
  46 #undef Debug
  47
  48 using System;
  49 using System.Collections;
  50 using System.Drawing;
  51 using System.Drawing.Text;
  52 using System.Text;
  53 using RTF=System.Windows.Forms.RTF;
  54
  55 namespace System.Windows.Forms {
  56         internal enum LineColor {
  57                 Red     = 0,
  58                 Black   = 1
  59         }
  60
  61         internal enum CaretSelection {
  62                 Position,       // Selection=Caret
  63                 Word,           // Selection=Word under caret
  64                 Line            // Selection=Line under caret
  65         }
  66
  67         [Flags]
  68         internal enum FormatSpecified {
  69                 None,
  70
  71                 BackColor = 2,
  72                 Font = 4,
  73                 Color = 8,
  74         }
  75
  76         internal enum CaretDirection {
  77                 CharForward,    // Move a char to the right
  78                 CharBack,       // Move a char to the left
  79                 LineUp,         // Move a line up
  80                 LineDown,       // Move a line down
  81                 Home,           // Move to the beginning of the line
  82                 End,            // Move to the end of the line
  83                 PgUp,           // Move one page up
  84                 PgDn,           // Move one page down
  85                 CtrlPgUp,       // Move caret to the first visible char in the viewport
  86                 CtrlPgDn,       // Move caret to the last visible char in the viewport
  87                 CtrlHome,       // Move to the beginning of the document
  88                 CtrlEnd,        // Move to the end of the document
  89                 WordBack,       // Move to the beginning of the previous word (or beginning of line)
  90                 WordForward,    // Move to the beginning of the next word (or end of line)
  91                 SelectionStart, // Move to the beginning of the current selection
  92                 SelectionEnd,   // Move to the end of the current selection
  93                 CharForwardNoWrap,   // Move a char forward, but don't wrap onto the next line
  94                 CharBackNoWrap      // Move a char backward, but don't wrap onto the previous line
  95         }
  96
  97         internal enum LineEnding {
  98                 Wrap,    // line wraps to the next line
  99                 Limp,    // \r
 100                 Hard,    // \r\n
 101                 Soft,    // \r\r\n
 102                 Rich,    // \n
 103
 104                 None
 105         }
 106
 107         internal class Document : ICloneable, IEnumerable {
 108                 #region Structures
 109                 // FIXME - go through code and check for places where
 110                 // we do explicit comparisons instead of using the compare overloads
 111                 internal struct Marker {
 112                         internal Line           line;
 113                         internal LineTag        tag;
 114                         internal int            pos;
 115                         internal int            height;
 116
 117                         public static bool operator<(Marker lhs, Marker rhs) {
 118                                 if (lhs.line.line_no < rhs.line.line_no) {
 119                                         return true;
 120                                 }
 121
 122                                 if (lhs.line.line_no == rhs.line.line_no) {
 123                                         if (lhs.pos < rhs.pos) {
 124                                                 return true;
 125                                         }
 126                                 }
 127                                 return false;
 128                         }
 129
 130                         public static bool operator>(Marker lhs, Marker rhs) {
 131                                 if (lhs.line.line_no > rhs.line.line_no) {
 132                                         return true;
 133                                 }
 134
 135                                 if (lhs.line.line_no == rhs.line.line_no) {
 136                                         if (lhs.pos > rhs.pos) {
 137                                                 return true;
 138                                         }
 139                                 }
 140                                 return false;
 141                         }
 142
 143                         public static bool operator==(Marker lhs, Marker rhs) {
 144                                 if ((lhs.line.line_no == rhs.line.line_no) && (lhs.pos == rhs.pos)) {
 145                                         return true;
 146                                 }
 147                                 return false;
 148                         }
 149
 150                         public static bool operator!=(Marker lhs, Marker rhs) {
 151                                 if ((lhs.line.line_no != rhs.line.line_no) || (lhs.pos != rhs.pos)) {
 152                                         return true;
 153                                 }
 154                                 return false;
 155                         }
 156
 157                         public void Combine(Line move_to_line, int move_to_line_length) {
 158                                 line = move_to_line;
 159                                 pos += move_to_line_length;
 160                                 tag = LineTag.FindTag(line, pos);
 161                         }
 162
 163                         // This is for future use, right now Document.Split does it by hand, with some added shortcut logic
 164                         public void Split(Line move_to_line, int split_at) {
 165                                 line = move_to_line;
 166                                 pos -= split_at;
 167                                 tag = LineTag.FindTag(line, pos);
 168                         }
 169
 170                         public override bool Equals(object obj) {
 171                                    return this==(Marker)obj;
 172                         }
 173
 174                         public override int GetHashCode() {
 175                                 return base.GetHashCode ();
 176                         }
 177
 178                         public override string ToString() {
 179                                 return "Marker Line " + line + ", Position " + pos;
 180                         }
 181
 182                 }
 183                 #endregion Structures
 184
 185                 #region Local Variables
 186                 private Line            document;
 187                 private int             lines;
 188                 private Line            sentinel;
 189                 private int             document_id;
 190                 private Random          random = new Random();
 191                 internal string         password_char;
 192                 private StringBuilder   password_cache;
 193                 private bool            calc_pass;
 194                 private int             char_count;
 195
 196                 // For calculating widths/heights
 197                 public static readonly StringFormat string_format = new StringFormat (StringFormat.GenericTypographic);
 198
 199                 private int             recalc_suspended;
 200                 private bool            recalc_pending;
 201                 private int             recalc_start = 1;   // This starts at one, since lines are 1 based
 202                 private int             recalc_end;
 203                 private bool            recalc_optimize;
 204
 205                 private int             update_suspended;
 206                 private bool update_pending;
 207                 private int update_start = 1;
 208
 209                 internal bool           multiline;
 210                 internal HorizontalAlignment alignment;
 211                 internal bool           wrap;
 212
 213                 internal UndoManager    undo;
 214
 215                 internal Marker         caret;
 216                 internal Marker         selection_start;
 217                 internal Marker         selection_end;
 218                 internal bool           selection_visible;
 219                 internal Marker         selection_anchor;
 220                 internal Marker         selection_prev;
 221                 internal bool           selection_end_anchor;
 222
 223                 internal int            viewport_x;
 224                 internal int            viewport_y;             // The visible area of the document
 225                 internal int            viewport_width;
 226                 internal int            viewport_height;
 227
 228                 internal int            document_x;             // Width of the document
 229                 internal int            document_y;             // Height of the document
 230
 231                 internal Rectangle      invalid;
 232
 233                 internal int            crlf_size;              // 1 or 2, depending on whether we use \r\n or just \n
 234
 235                 internal TextBoxBase    owner;                  // Who's owning us?
 236                 static internal int     caret_width = 1;
 237                 static internal int     caret_shift = 1;
 238
 239                 internal int left_margin = 2;  // A left margin for all lines
 240                 internal int top_margin = 2;
 241                 internal int right_margin = 2;
 242                 #endregion      // Local Variables
 243
 244                 #region Constructors
 245                 internal Document (TextBoxBase owner)
 246                 {
 247                         lines = 0;
 248
 249                         this.owner = owner;
 250
 251                         multiline = true;
 252                         password_char = "";
 253                         calc_pass = false;
 254                         recalc_pending = false;
 255
 256                         // Tree related stuff
 257                         sentinel = new Line (this, LineEnding.None);
 258                         sentinel.color = LineColor.Black;
 259
 260                         document = sentinel;
 261
 262                         // We always have a blank line
 263                         owner.HandleCreated += new EventHandler(owner_HandleCreated);
 264                         owner.VisibleChanged += new EventHandler(owner_VisibleChanged);
 265
 266                         Add (1, String.Empty, owner.Font, owner.ForeColor, LineEnding.None);
 267
 268                         undo = new UndoManager (this);
 269
 270                         selection_visible = false;
 271                         selection_start.line = this.document;
 272                         selection_start.pos = 0;
 273                         selection_start.tag = selection_start.line.tags;
 274                         selection_end.line = this.document;
 275                         selection_end.pos = 0;
 276                         selection_end.tag = selection_end.line.tags;
 277                         selection_anchor.line = this.document;
 278                         selection_anchor.pos = 0;
 279                         selection_anchor.tag = selection_anchor.line.tags;
 280                         caret.line = this.document;
 281                         caret.pos = 0;
 282                         caret.tag = caret.line.tags;
 283
 284                         viewport_x = 0;
 285                         viewport_y = 0;
 286
 287                         crlf_size = 2;
 288
 289                         // Default selection is empty
 290
 291                         document_id = random.Next();
 292
 293                         string_format.Trimming = StringTrimming.None;
 294                         string_format.FormatFlags = StringFormatFlags.DisplayFormatControl;
 295
 296                         UpdateMargins ();
 297                 }
 298                 #endregion
 299
 300                 #region Internal Properties
 301                 internal Line Root {
 302                         get {
 303                                 return document;
 304                         }
 305
 306                         set {
 307                                 document = value;
 308                         }
 309                 }
 310
 311                 internal int Lines {
 312                         get {
 313                                 return lines;
 314                         }
 315                 }
 316
 317                 internal Line CaretLine {
 318                         get {
 319                                 return caret.line;
 320                         }
 321                 }
 322
 323                 internal int CaretPosition {
 324                         get {
 325                                 return caret.pos;
 326                         }
 327                 }
 328
 329                 internal Point Caret {
 330                         get {
 331                                 return new Point((int)caret.tag.line.widths[caret.pos] + caret.line.X, caret.line.Y);
 332                         }
 333                 }
 334
 335                 internal LineTag CaretTag {
 336                         get {
 337                                 return caret.tag;
 338                         }
 339
 340                         set {
 341                                 caret.tag = value;
 342                         }
 343                 }
 344
 345                 internal int CRLFSize {
 346                         get {
 347                                 return crlf_size;
 348                         }
 349
 350                         set {
 351                                 crlf_size = value;
 352                         }
 353                 }
 354
 355                 internal string PasswordChar {
 356                         get {
 357                                 return password_char;
 358                         }
 359
 360                         set {
 361                                 password_char = value;
 362                                 PasswordCache.Length = 0;
 363                                 if ((password_char.Length != 0) && (password_char[0] != '\0')) {
 364                                         calc_pass = true;
 365                                 } else {
 366                                         calc_pass = false;
 367                                 }
 368                         }
 369                 }
 370
 371                 private StringBuilder PasswordCache {
 372                         get {
 373                                 if (password_cache == null)
 374                                           password_cache = new StringBuilder();
 375                                 return password_cache;
 376                         }
 377                 }
 378
 379                 internal int ViewPortX {
 380                         get {
 381                                 return viewport_x;
 382                         }
 383
 384                         set {
 385                                 viewport_x = value;
 386                         }
 387                 }
 388
 389                 internal int Length {
 390                         get {
 391                                 return char_count + lines - 1;  // Add \n for each line but the last
 392                         }
 393                 }
 394
 395                 private int CharCount {
 396                         get {
 397                                 return char_count;
 398                         }
 399
 400                         set {
 401                                 char_count = value;
 402
 403                                 if (LengthChanged != null) {
 404                                         LengthChanged(this, EventArgs.Empty);
 405                                 }
 406                         }
 407                 }
 408
 409                 internal int ViewPortY {
 410                         get {
 411                                 return viewport_y;
 412                         }
 413
 414                         set {
 415                                 viewport_y = value;
 416                         }
 417                 }
 418
 419                 internal int ViewPortWidth {
 420                         get {
 421                                 return viewport_width;
 422                         }
 423
 424                         set {
 425                                 viewport_width = value;
 426                         }
 427                 }
 428
 429                 internal int ViewPortHeight {
 430                         get {
 431                                 return viewport_height;
 432                         }
 433
 434                         set {
 435                                 viewport_height = value;
 436                         }
 437                 }
 438
 439
 440                 internal int Width {
 441                         get {
 442                                 return this.document_x;
 443                         }
 444                 }
 445
 446                 internal int Height {
 447                         get {
 448                                 return this.document_y;
 449                         }
 450                 }
 451
 452                 internal bool SelectionVisible {
 453                         get {
 454                                 return selection_visible;
 455                         }
 456                 }
 457
 458                 internal bool Wrap {
 459                         get {
 460                                 return wrap;
 461                         }
 462
 463                         set {
 464                                 wrap = value;
 465                         }
 466                 }
 467
 468                 #endregion      // Internal Properties
 469
 470                 #region Private Methods
 471
 472                 internal void UpdateMargins ()
 473                 {
 474                         switch (owner.actual_border_style) {
 475                                 case BorderStyle.None:
 476                                         left_margin = 0;
 477                                         top_margin = 0;
 478                                         right_margin = 1;
 479                                         break;
 480                                 case BorderStyle.FixedSingle:
 481                                         left_margin = 2;
 482                                         top_margin = 2;
 483                                         right_margin = 3;
 484                                         break;
 485                                 case BorderStyle.Fixed3D:
 486                                         left_margin = 1;
 487                                         top_margin = 1;
 488                                         right_margin = 2;
 489                                         break;
 490                         }
 491                 }
 492
 493                 internal void SuspendRecalc ()
 494                 {
 495                         recalc_suspended++;
 496                 }
 497
 498                 internal void ResumeRecalc (bool immediate_update)
 499                 {
 500                         if (recalc_suspended > 0)
 501                                 recalc_suspended--;
 502
 503                         if (immediate_update && recalc_suspended == 0 && recalc_pending) {
 504                                 RecalculateDocument (owner.CreateGraphicsInternal(), recalc_start, recalc_end, recalc_optimize);
 505                                 recalc_pending = false;
 506                         }
 507                 }
 508
 509                 internal void SuspendUpdate ()
 510                 {
 511                         update_suspended++;
 512                 }
 513
 514                 internal void ResumeUpdate (bool immediate_update)
 515                 {
 516                         if (update_suspended > 0)
 517                                 update_suspended--;
 518
 519                         if (immediate_update && update_suspended == 0 && update_pending) {
 520                                 UpdateView (GetLine (update_start), 0);
 521                                 update_pending = false;
 522                         }
 523                 }
 524
 525                 // For debugging
 526                 internal int DumpTree(Line line, bool with_tags) {
 527                         int     total;
 528
 529                         total = 1;
 530
 531                         Console.Write("Line {0} [# {1}], Y: {2}, ending style: {3},  Text: '{4}'",
 532                                         line.line_no, line.GetHashCode(), line.Y, line.ending,
 533                                         line.text != null ? line.text.ToString() : "undefined");
 534
 535                         if (line.left == sentinel) {
 536                                 Console.Write(", left = sentinel");
 537                         } else if (line.left == null) {
 538                                 Console.Write(", left = NULL");
 539                         }
 540
 541                         if (line.right == sentinel) {
 542                                 Console.Write(", right = sentinel");
 543                         } else if (line.right == null) {
 544                                 Console.Write(", right = NULL");
 545                         }
 546
 547                         Console.WriteLine("");
 548
 549                         if (with_tags) {
 550                                 LineTag tag;
 551                                 int     count;
 552                                 int     length;
 553
 554                                 tag = line.tags;
 555                                 count = 1;
 556                                 length = 0;
 557                                 Console.Write("   Tags: ");
 558                                 while (tag != null) {
 559                                         Console.Write("{0} <{1}>-<{2}>", count++, tag.start, tag.End
 560                                                         /*line.text.ToString (tag.start - 1, tag.length)*/);
 561                                         length += tag.Length;
 562
 563                                         if (tag.line != line) {
 564                                                 Console.Write("BAD line link");
 565                                                 throw new Exception("Bad line link in tree");
 566                                         }
 567                                         tag = tag.next;
 568                                         if (tag != null) {
 569                                                 Console.Write(", ");
 570                                         }
 571                                 }
 572                                 if (length > line.text.Length) {
 573                                         throw new Exception(String.Format("Length of tags more than length of text on line (expected {0} calculated {1})", line.text.Length, length));
 574                                 } else if (length < line.text.Length) {
 575                                         throw new Exception(String.Format("Length of tags less than length of text on line (expected {0} calculated {1})", line.text.Length, length));
 576                                 }
 577                                 Console.WriteLine("");
 578                         }
 579                         if (line.left != null) {
 580                                 if (line.left != sentinel) {
 581                                         total += DumpTree(line.left, with_tags);
 582                                 }
 583                         } else {
 584                                 if (line != sentinel) {
 585                                         throw new Exception("Left should not be NULL");
 586                                 }
 587                         }
 588
 589                         if (line.right != null) {
 590                                 if (line.right != sentinel) {
 591                                         total += DumpTree(line.right, with_tags);
 592                                 }
 593                         } else {
 594                                 if (line != sentinel) {
 595                                         throw new Exception("Right should not be NULL");
 596                                 }
 597                         }
 598
 599                         for (int i = 1; i <= this.lines; i++) {
 600                                 if (GetLine(i) == null) {
 601                                         throw new Exception(String.Format("Hole in line order, missing {0}", i));
 602                                 }
 603                         }
 604
 605                         if (line == this.Root) {
 606                                 if (total < this.lines) {
 607                                         throw new Exception(String.Format("Not enough nodes in tree, found {0}, expected {1}", total, this.lines));
 608                                 } else if (total > this.lines) {
 609                                         throw new Exception(String.Format("Too many nodes in tree, found {0}, expected {1}", total, this.lines));
 610                                 }
 611                         }
 612
 613                         return total;
 614                 }
 615
 616                 private void SetSelectionVisible (bool value)
 617                 {
 618                         selection_visible = value;
 619
 620                         // cursor and selection are enemies, we can't have both in the same room at the same time
 621                         if (owner.IsHandleCreated && !owner.show_caret_w_selection)
 622                                 XplatUI.CaretVisible (owner.Handle, !selection_visible);
 623                 }
 624
 625                 private void DecrementLines(int line_no) {
 626                         int     current;
 627
 628                         current = line_no;
 629                         while (current <= lines) {
 630                                 GetLine(current).line_no--;
 631                                 current++;
 632                         }
 633                         return;
 634                 }
 635
 636                 private void IncrementLines(int line_no) {
 637                         int     current;
 638
 639                         current = this.lines;
 640                         while (current >= line_no) {
 641                                 GetLine(current).line_no++;
 642                                 current--;
 643                         }
 644                         return;
 645                 }
 646
 647                 private void RebalanceAfterAdd(Line line1) {
 648                         Line    line2;
 649
 650                         while ((line1 != document) && (line1.parent.color == LineColor.Red)) {
 651                                 if (line1.parent == line1.parent.parent.left) {
 652                                         line2 = line1.parent.parent.right;
 653
 654                                         if ((line2 != null) && (line2.color == LineColor.Red)) {
 655                                                 line1.parent.color = LineColor.Black;
 656                                                 line2.color = LineColor.Black;
 657                                                 line1.parent.parent.color = LineColor.Red;
 658                                                 line1 = line1.parent.parent;
 659                                         } else {
 660                                                 if (line1 == line1.parent.right) {
 661                                                         line1 = line1.parent;
 662                                                         RotateLeft(line1);
 663                                                 }
 664
 665                                                 line1.parent.color = LineColor.Black;
 666                                                 line1.parent.parent.color = LineColor.Red;
 667
 668                                                 RotateRight(line1.parent.parent);
 669                                         }
 670                                 } else {
 671                                         line2 = line1.parent.parent.left;
 672
 673                                         if ((line2 != null) && (line2.color == LineColor.Red)) {
 674                                                 line1.parent.color = LineColor.Black;
 675                                                 line2.color = LineColor.Black;
 676                                                 line1.parent.parent.color = LineColor.Red;
 677                                                 line1 = line1.parent.parent;
 678                                         } else {
 679                                                 if (line1 == line1.parent.left) {
 680                                                         line1 = line1.parent;
 681                                                         RotateRight(line1);
 682                                                 }
 683
 684                                                 line1.parent.color = LineColor.Black;
 685                                                 line1.parent.parent.color = LineColor.Red;
 686                                                 RotateLeft(line1.parent.parent);
 687                                         }
 688                                 }
 689                         }
 690                         document.color = LineColor.Black;
 691                 }
 692
 693                 private void RebalanceAfterDelete(Line line1) {
 694                         Line line2;
 695
 696                         while ((line1 != document) && (line1.color == LineColor.Black)) {
 697                                 if (line1 == line1.parent.left) {
 698                                         line2 = line1.parent.right;
 699                                         if (line2.color == LineColor.Red) {
 700                                                 line2.color = LineColor.Black;
 701                                                 line1.parent.color = LineColor.Red;
 702                                                 RotateLeft(line1.parent);
 703                                                 line2 = line1.parent.right;
 704                                         }
 705                                         if ((line2.left.color == LineColor.Black) && (line2.right.color == LineColor.Black)) {
 706                                                 line2.color = LineColor.Red;
 707                                                 line1 = line1.parent;
 708                                         } else {
 709                                                 if (line2.right.color == LineColor.Black) {
 710                                                         line2.left.color = LineColor.Black;
 711                                                         line2.color = LineColor.Red;
 712                                                         RotateRight(line2);
 713                                                         line2 = line1.parent.right;
 714                                                 }
 715                                                 line2.color = line1.parent.color;
 716                                                 line1.parent.color = LineColor.Black;
 717                                                 line2.right.color = LineColor.Black;
 718                                                 RotateLeft(line1.parent);
 719                                                 line1 = document;
 720                                         }
 721                                 } else {
 722                                         line2 = line1.parent.left;
 723                                         if (line2.color == LineColor.Red) {
 724                                                 line2.color = LineColor.Black;
 725                                                 line1.parent.color = LineColor.Red;
 726                                                 RotateRight(line1.parent);
 727                                                 line2 = line1.parent.left;
 728                                         }
 729                                         if ((line2.right.color == LineColor.Black) && (line2.left.color == LineColor.Black)) {
 730                                                 line2.color = LineColor.Red;
 731                                                 line1 = line1.parent;
 732                                         } else {
 733                                                 if (line2.left.color == LineColor.Black) {
 734                                                         line2.right.color = LineColor.Black;
 735                                                         line2.color = LineColor.Red;
 736                                                         RotateLeft(line2);
 737                                                         line2 = line1.parent.left;
 738                                                 }
 739                                                 line2.color = line1.parent.color;
 740                                                 line1.parent.color = LineColor.Black;
 741                                                 line2.left.color = LineColor.Black;
 742                                                 RotateRight(line1.parent);
 743                                                 line1 = document;
 744                                         }
 745                                 }
 746                         }
 747                         line1.color = LineColor.Black;
 748                 }
 749
 750                 private void RotateLeft(Line line1) {
 751                         Line    line2 = line1.right;
 752
 753                         line1.right = line2.left;
 754
 755                         if (line2.left != sentinel) {
 756                                 line2.left.parent = line1;
 757                         }
 758
 759                         if (line2 != sentinel) {
 760                                 line2.parent = line1.parent;
 761                         }
 762
 763                         if (line1.parent != null) {
 764                                 if (line1 == line1.parent.left) {
 765                                         line1.parent.left = line2;
 766                                 } else {
 767                                         line1.parent.right = line2;
 768                                 }
 769                         } else {
 770                                 document = line2;
 771                         }
 772
 773                         line2.left = line1;
 774                         if (line1 != sentinel) {
 775                                 line1.parent = line2;
 776                         }
 777                 }
 778
 779                 private void RotateRight(Line line1) {
 780                         Line line2 = line1.left;
 781
 782                         line1.left = line2.right;
 783
 784                         if (line2.right != sentinel) {
 785                                 line2.right.parent = line1;
 786                         }
 787
 788                         if (line2 != sentinel) {
 789                                 line2.parent = line1.parent;
 790                         }
 791
 792                         if (line1.parent != null) {
 793                                 if (line1 == line1.parent.right) {
 794                                         line1.parent.right = line2;
 795                                 } else {
 796                                         line1.parent.left = line2;
 797                                 }
 798                         } else {
 799                                 document = line2;
 800                         }
 801
 802                         line2.right = line1;
 803                         if (line1 != sentinel) {
 804                                 line1.parent = line2;
 805                         }
 806                 }
 807
 808
 809                 internal void UpdateView(Line line, int pos) {
 810                         if (!owner.IsHandleCreated) {
 811                                 return;
 812                         }
 813
 814                         if (update_suspended > 0) {
 815                                 update_start = Math.Min (update_start, line.line_no);
 816                                 // update_end = Math.Max (update_end, line.line_no);
 817                                 // recalc_optimize = true;
 818                                 update_pending = true;
 819                                 return;
 820                         }
 821
 822                         // Optimize invalidation based on Line alignment
 823                         if (RecalculateDocument(owner.CreateGraphicsInternal(), line.line_no, line.line_no, true)) {
 824                                 // Lineheight changed, invalidate the rest of the document
 825                                 if ((line.Y - viewport_y) >=0 ) {
 826                                         // We formatted something that's in view, only draw parts of the screen
 827                                         owner.Invalidate(new Rectangle(0, line.Y - viewport_y, viewport_width, owner.Height - line.Y - viewport_y));
 828                                 } else {
 829                                         // The tag was above the visible area, draw everything
 830                                         owner.Invalidate();
 831                                 }
 832                         } else {
 833                                 switch(line.alignment) {
 834                                         case HorizontalAlignment.Left: {
 835                                                 owner.Invalidate(new Rectangle(line.X + (int)line.widths[pos] - viewport_x - 1, line.Y - viewport_y, viewport_width, line.height + 1));
 836                                                 break;
 837                                         }
 838
 839                                         case HorizontalAlignment.Center: {
 840                                                 owner.Invalidate(new Rectangle(line.X, line.Y - viewport_y, viewport_width, line.height + 1));
 841                                                 break;
 842                                         }
 843
 844                                         case HorizontalAlignment.Right: {
 845                                                 owner.Invalidate(new Rectangle(line.X, line.Y - viewport_y, (int)line.widths[pos + 1] - viewport_x + line.X, line.height + 1));
 846                                                 break;
 847                                         }
 848                                 }
 849                         }
 850                 }
 851
 852
 853                 // Update display from line, down line_count lines; pos is unused, but required for the signature
 854                 internal void UpdateView(Line line, int line_count, int pos) {
 855                         if (!owner.IsHandleCreated) {
 856                                 return;
 857                         }
 858
 859                         if (recalc_suspended > 0) {
 860                                 recalc_start = Math.Min (recalc_start, line.line_no);
 861                                 recalc_end = Math.Max (recalc_end, line.line_no + line_count);
 862                                 recalc_optimize = true;
 863                                 recalc_pending = true;
 864                                 return;
 865                         }
 866
 867                         int start_line_top = line.Y;
 868
 869                         int end_line_bottom;
 870                         Line end_line;
 871
 872                         end_line = GetLine (line.line_no + line_count);
 873                         if (end_line == null)
 874                                 end_line = GetLine (lines);
 875
 876
 877                         end_line_bottom = end_line.Y + end_line.height;
 878
 879                         if (RecalculateDocument(owner.CreateGraphicsInternal(), line.line_no, line.line_no + line_count, true)) {
 880                                 // Lineheight changed, invalidate the rest of the document
 881                                 if ((line.Y - viewport_y) >=0 ) {
 882                                         // We formatted something that's in view, only draw parts of the screen
 883                                         owner.Invalidate(new Rectangle(0, line.Y - viewport_y, viewport_width, owner.Height - line.Y - viewport_y));
 884                                 } else {
 885                                         // The tag was above the visible area, draw everything
 886                                         owner.Invalidate();
 887                                 }
 888                         } else {
 889                                 int x = 0 - viewport_x;
 890                                 int w = viewport_width;
 891                                 int y = Math.Min (start_line_top - viewport_y, line.Y - viewport_y);
 892                                 int h = Math.Max (end_line_bottom - y, end_line.Y + end_line.height - y);
 893
 894                                 owner.Invalidate (new Rectangle (x, y, w, h));
 895                         }
 896                 }
 897                 #endregion      // Private Methods
 898
 899                 #region Internal Methods
 900                 // Clear the document and reset state
 901                 internal void Empty() {
 902
 903                         document = sentinel;
 904                         lines = 0;
 905
 906                         // We always have a blank line
 907                         Add (1, String.Empty, owner.Font, owner.ForeColor, LineEnding.None);
 908
 909                         this.RecalculateDocument(owner.CreateGraphicsInternal());
 910                         PositionCaret(0, 0);
 911
 912                         SetSelectionVisible (false);
 913
 914                         selection_start.line = this.document;
 915                         selection_start.pos = 0;
 916                         selection_start.tag = selection_start.line.tags;
 917                         selection_end.line = this.document;
 918                         selection_end.pos = 0;
 919                         selection_end.tag = selection_end.line.tags;
 920                         char_count = 0;
 921
 922                         viewport_x = 0;
 923                         viewport_y = 0;
 924
 925                         document_x = 0;
 926                         document_y = 0;
 927
 928                         if (owner.IsHandleCreated)
 929                                 owner.Invalidate ();
 930                 }
 931
 932                 internal void PositionCaret(Line line, int pos) {
 933                         caret.tag = line.FindTag (pos);
 934
 935                         MoveCaretToTextTag ();
 936
 937                         caret.line = line;
 938                         caret.pos = pos;
 939
 940                         if (owner.IsHandleCreated) {
 941                                 if (owner.Focused) {
 942                                         if (caret.height != caret.tag.height)
 943                                                 XplatUI.CreateCaret (owner.Handle, caret_width, caret.height);
 944                                         XplatUI.SetCaretPos(owner.Handle, (int)caret.tag.line.widths[caret.pos] + caret.line.X - viewport_x, caret.line.Y + caret.tag.shift - viewport_y + caret_shift);
 945                                 }
 946
 947                                 if (CaretMoved != null) CaretMoved(this, EventArgs.Empty);
 948                         }
 949
 950                         // We set this at the end because we use the heights to determine whether or
 951                         // not we need to recreate the caret
 952                         caret.height = caret.tag.height;
 953
 954                 }
 955
 956                 internal void PositionCaret(int x, int y) {
 957                         if (!owner.IsHandleCreated) {
 958                                 return;
 959                         }
 960
 961                         caret.tag = FindCursor(x, y, out caret.pos);
 962
 963                         MoveCaretToTextTag ();
 964
 965                         caret.line = caret.tag.line;
 966                         caret.height = caret.tag.height;
 967
 968                         if (owner.ShowSelection && (!selection_visible || owner.show_caret_w_selection)) {
 969                                 XplatUI.CreateCaret (owner.Handle, caret_width, caret.height);
 970                                 XplatUI.SetCaretPos(owner.Handle, (int)caret.tag.line.widths[caret.pos] + caret.line.X - viewport_x, caret.line.Y + caret.tag.shift - viewport_y + caret_shift);
 971                         }
 972
 973                         if (CaretMoved != null) CaretMoved(this, EventArgs.Empty);
 974                 }
 975
 976                 internal void CaretHasFocus() {
 977                         if ((caret.tag != null) && owner.IsHandleCreated) {
 978                                 XplatUI.CreateCaret(owner.Handle, caret_width, caret.height);
 979                                 XplatUI.SetCaretPos(owner.Handle, (int)caret.tag.line.widths[caret.pos] + caret.line.X - viewport_x, caret.line.Y + caret.tag.shift - viewport_y + caret_shift);
 980
 981                                 DisplayCaret ();
 982                         }
 983
 984                         if (owner.IsHandleCreated && SelectionLength () > 0) {
 985                                 InvalidateSelectionArea ();
 986                         }
 987                 }
 988
 989                 internal void CaretLostFocus() {
 990                         if (!owner.IsHandleCreated) {
 991                                 return;
 992                         }
 993                         XplatUI.DestroyCaret(owner.Handle);
 994                 }
 995
 996                 internal void AlignCaret() {
 997                         if (!owner.IsHandleCreated) {
 998                                 return;
 999                         }
1000
1001                         caret.tag = LineTag.FindTag (caret.line, caret.pos);
1002
1003                         MoveCaretToTextTag ();
1004
1005                         caret.height = caret.tag.height;
1006
1007                         if (owner.Focused) {
1008                                 XplatUI.CreateCaret(owner.Handle, caret_width, caret.height);
1009                                 XplatUI.SetCaretPos(owner.Handle, (int)caret.tag.line.widths[caret.pos] + caret.line.X - viewport_x, caret.line.Y + caret.tag.shift - viewport_y + caret_shift);
1010                                 DisplayCaret ();
1011                         }
1012
1013                         if (CaretMoved != null) CaretMoved(this, EventArgs.Empty);
1014                 }
1015
1016                 internal void UpdateCaret() {
1017                         if (!owner.IsHandleCreated || caret.tag == null) {
1018                                 return;
1019                         }
1020
1021                         MoveCaretToTextTag ();
1022
1023                         if (caret.tag.height != caret.height) {
1024                                 caret.height = caret.tag.height;
1025                                 if (owner.Focused) {
1026                                         XplatUI.CreateCaret(owner.Handle, caret_width, caret.height);
1027                                 }
1028                         }
1029
1030                         if (owner.Focused) {
1031                                 XplatUI.SetCaretPos(owner.Handle, (int)caret.tag.line.widths[caret.pos] + caret.line.X - viewport_x, caret.line.Y + caret.tag.shift - viewport_y + caret_shift);
1032                                 DisplayCaret ();
1033                         }
1034
1035                         if (CaretMoved != null) CaretMoved(this, EventArgs.Empty);
1036                 }
1037
1038                 internal void DisplayCaret() {
1039                         if (!owner.IsHandleCreated) {
1040                                 return;
1041                         }
1042
1043                         if (owner.ShowSelection && (!selection_visible || owner.show_caret_w_selection)) {
1044                                 XplatUI.CaretVisible(owner.Handle, true);
1045                         }
1046                 }
1047
1048                 internal void HideCaret() {
1049                         if (!owner.IsHandleCreated) {
1050                                 return;
1051                         }
1052
1053                         if (owner.Focused) {
1054                                 XplatUI.CaretVisible(owner.Handle, false);
1055                         }
1056                 }
1057
1058
1059                 internal void MoveCaretToTextTag ()
1060                 {
1061                         if (caret.tag == null || caret.tag.IsTextTag)
1062                                 return;
1063
1064
1065
1066                         if (caret.pos < caret.tag.start) {
1067                                 caret.tag = caret.tag.previous;
1068                         } else {
1069                                 caret.tag = caret.tag.next;
1070                         }
1071                 }
1072
1073                 internal void MoveCaret(CaretDirection direction) {
1074                         // FIXME should we use IsWordSeparator to detect whitespace, instead
1075                         // of looking for actual spaces in the Word move cases?
1076
1077                         bool nowrap = false;
1078                         switch(direction) {
1079                                 case CaretDirection.CharForwardNoWrap:
1080                                         nowrap = true;
1081                                         goto case CaretDirection.CharForward;
1082                                 case CaretDirection.CharForward: {
1083                                         caret.pos++;
1084                                         if (caret.pos > caret.line.TextLengthWithoutEnding ()) {
1085                                                 if (!nowrap) {
1086                                                         // Go into next line
1087                                                         if (caret.line.line_no < this.lines) {
1088                                                                 caret.line = GetLine(caret.line.line_no+1);
1089                                                                 caret.pos = 0;
1090                                                                 caret.tag = caret.line.tags;
1091                                                         } else {
1092                                                                 caret.pos--;
1093                                                         }
1094                                                 } else {
1095                                                         // Single line; we stay where we are
1096                                                         caret.pos--;
1097                                                 }
1098                                         } else {
1099                                                 if ((caret.tag.start - 1 + caret.tag.Length) < caret.pos) {
1100                                                         caret.tag = caret.tag.next;
1101                                                 }
1102                                         }
1103                                         UpdateCaret();
1104                                         return;
1105                                 }
1106
1107                                 case CaretDirection.CharBackNoWrap:
1108                                         nowrap = true;
1109                                         goto case CaretDirection.CharBack;
1110                                 case CaretDirection.CharBack: {
1111                                         if (caret.pos > 0) {
1112                                                 // caret.pos--; // folded into the if below
1113
1114                                                 if (--caret.pos > 0) {
1115                                                         if (caret.tag.start > caret.pos) {
1116                                                                 caret.tag = caret.tag.previous;
1117                                                         }
1118                                                 }
1119                                         } else {
1120                                                 if (caret.line.line_no > 1 && !nowrap) {
1121                                                         caret.line = GetLine(caret.line.line_no - 1);
1122                                                         caret.pos = caret.line.TextLengthWithoutEnding ();
1123                                                         caret.tag = LineTag.FindTag(caret.line, caret.pos);
1124                                                 }
1125                                         }
1126                                         UpdateCaret();
1127                                         return;
1128                                 }
1129
1130                                 case CaretDirection.WordForward: {
1131                                         int len;
1132
1133                                         len = caret.line.text.Length;
1134                                         if (caret.pos < len) {
1135                                                 while ((caret.pos < len) && (caret.line.text[caret.pos] != ' ')) {
1136                                                         caret.pos++;
1137                                                 }
1138                                                 if (caret.pos < len) {
1139                                                         // Skip any whitespace
1140                                                         while ((caret.pos < len) && (caret.line.text[caret.pos] == ' ')) {
1141                                                                 caret.pos++;
1142                                                         }
1143                                                 }
1144                                                 caret.tag = LineTag.FindTag(caret.line, caret.pos);
1145                                         } else {
1146                                                 if (caret.line.line_no < this.lines) {
1147                                                         caret.line = GetLine(caret.line.line_no + 1);
1148                                                         caret.pos = 0;
1149                                                         caret.tag = caret.line.tags;
1150                                                 }
1151                                         }
1152                                         UpdateCaret();
1153                                         return;
1154                                 }
1155
1156                                 case CaretDirection.WordBack: {
1157                                         if (caret.pos > 0) {
1158                                                 caret.pos--;
1159
1160                                                 while ((caret.pos > 0) && (caret.line.text[caret.pos] == ' ')) {
1161                                                         caret.pos--;
1162                                                 }
1163
1164                                                 while ((caret.pos > 0) && (caret.line.text[caret.pos] != ' ')) {
1165                                                         caret.pos--;
1166                                                 }
1167
1168                                                 if (caret.line.text.ToString(caret.pos, 1) == " ") {
1169                                                         if (caret.pos != 0) {
1170                                                                 caret.pos++;
1171                                                         } else {
1172                                                                 caret.line = GetLine(caret.line.line_no - 1);
1173                                                                 caret.pos = caret.line.text.Length;
1174                                                         }
1175                                                 }
1176                                                 caret.tag = LineTag.FindTag(caret.line, caret.pos);
1177                                         } else {
1178                                                 if (caret.line.line_no > 1) {
1179                                                         caret.line = GetLine(caret.line.line_no - 1);
1180                                                         caret.pos = caret.line.text.Length;
1181                                                         caret.tag = LineTag.FindTag(caret.line, caret.pos);
1182                                                 }
1183                                         }
1184                                         UpdateCaret();
1185                                         return;
1186                                 }
1187
1188                                 case CaretDirection.LineUp: {
1189                                         if (caret.line.line_no > 1) {
1190                                                 int     pixel;
1191
1192                                                 pixel = (int)caret.line.widths[caret.pos];
1193                                                 PositionCaret(pixel, GetLine(caret.line.line_no - 1).Y);
1194
1195                                                 DisplayCaret ();
1196                                         }
1197                                         return;
1198                                 }
1199
1200                                 case CaretDirection.LineDown: {
1201                                         if (caret.line.line_no < lines) {
1202                                                 int     pixel;
1203
1204                                                 pixel = (int)caret.line.widths[caret.pos];
1205                                                 PositionCaret(pixel, GetLine(caret.line.line_no + 1).Y);
1206
1207                                                 DisplayCaret ();
1208                                         }
1209                                         return;
1210                                 }
1211
1212                                 case CaretDirection.Home: {
1213                                         if (caret.pos > 0) {
1214                                                 caret.pos = 0;
1215                                                 caret.tag = caret.line.tags;
1216                                                 UpdateCaret();
1217                                         }
1218                                         return;
1219                                 }
1220
1221                                 case CaretDirection.End: {
1222                                         if (caret.pos < caret.line.TextLengthWithoutEnding ()) {
1223                                                 caret.pos = caret.line.TextLengthWithoutEnding ();
1224                                                 caret.tag = LineTag.FindTag(caret.line, caret.pos);
1225                                                 UpdateCaret();
1226                                         }
1227                                         return;
1228                                 }
1229
1230                                 case CaretDirection.PgUp: {
1231
1232                                         if (viewport_y == 0 && owner.richtext) {
1233                                                 owner.vscroll.Value = 0;
1234                                                 Line line = GetLine (1);
1235                                                 PositionCaret (line, 0);
1236                                         }
1237
1238                                         int y_offset = caret.line.Y + caret.line.height - 1 - viewport_y;
1239                                         int index;
1240                                         LineTag top = FindCursor ((int) caret.line.widths [caret.pos],
1241                                                         viewport_y - viewport_height, out index);
1242
1243                                         owner.vscroll.Value = Math.Min (top.line.Y, owner.vscroll.Maximum - viewport_height);
1244                                         PositionCaret ((int) caret.line.widths [caret.pos], y_offset + viewport_y);
1245
1246                                         return;
1247                                 }
1248
1249                                 case CaretDirection.PgDn: {
1250
1251                                         if (viewport_y + viewport_height >= document_y && owner.richtext) {
1252                                                 owner.vscroll.Value = owner.vscroll.Maximum - viewport_height + 1;
1253                                                 Line line = GetLine (lines);
1254                                                 PositionCaret (line, line.Text.Length);
1255                                         }
1256
1257                                         int y_offset = caret.line.Y - viewport_y;
1258                                         int index;
1259                                         LineTag top = FindCursor ((int) caret.line.widths [caret.pos],
1260                                                         viewport_y + viewport_height, out index);
1261
1262                                         owner.vscroll.Value = Math.Min (top.line.Y, owner.vscroll.Maximum - viewport_height);
1263                                         PositionCaret ((int) caret.line.widths [caret.pos], y_offset + viewport_y);
1264
1265                                         return;
1266                                 }
1267
1268                                 case CaretDirection.CtrlPgUp: {
1269                                         PositionCaret(0, viewport_y);
1270                                         DisplayCaret ();
1271                                         return;
1272                                 }
1273
1274                                 case CaretDirection.CtrlPgDn: {
1275                                         Line    line;
1276                                         LineTag tag;
1277                                         int     index;
1278
1279                                         tag = FindTag(0, viewport_y + viewport_height, out index, false);
1280                                         if (tag.line.line_no > 1) {
1281                                                 line = GetLine(tag.line.line_no - 1);
1282                                         } else {
1283                                                 line = tag.line;
1284                                         }
1285                                         PositionCaret(line, line.Text.Length);
1286                                         DisplayCaret ();
1287                                         return;
1288                                 }
1289
1290                                 case CaretDirection.CtrlHome: {
1291                                         caret.line = GetLine(1);
1292                                         caret.pos = 0;
1293                                         caret.tag = caret.line.tags;
1294
1295                                         UpdateCaret();
1296                                         return;
1297                                 }
1298
1299                                 case CaretDirection.CtrlEnd: {
1300                                         caret.line = GetLine(lines);
1301                                         caret.pos = caret.line.TextLengthWithoutEnding ();
1302                                         caret.tag = LineTag.FindTag(caret.line, caret.pos);
1303
1304                                         UpdateCaret();
1305                                         return;
1306                                 }
1307
1308                                 case CaretDirection.SelectionStart: {
1309                                         caret.line = selection_start.line;
1310                                         caret.pos = selection_start.pos;
1311                                         caret.tag = selection_start.tag;
1312
1313                                         UpdateCaret();
1314                                         return;
1315                                 }
1316
1317                                 case CaretDirection.SelectionEnd: {
1318                                         caret.line = selection_end.line;
1319                                         caret.pos = selection_end.pos;
1320                                         caret.tag = selection_end.tag;
1321
1322                                         UpdateCaret();
1323                                         return;
1324                                 }
1325                         }
1326                 }
1327
1328                 internal void DumpDoc ()
1329                 {
1330                         Console.WriteLine ("<doc lines='{0}'>", lines);
1331                         for (int i = 1; i <= lines ; i++) {
1332                                 Line line = GetLine (i);
1333                                 Console.WriteLine ("<line no='{0}' ending='{1}'>", line.line_no, line.ending);
1334
1335                                 LineTag tag = line.tags;
1336                                 while (tag != null) {
1337                                         Console.Write ("\t<tag type='{0}' span='{1}->{2}' font='{3}' color='{4}'>",
1338                                                         tag.GetType (), tag.start, tag.Length, tag.font, tag.color);
1339                                         Console.Write (tag.Text ());
1340                                         Console.WriteLine ("</tag>");
1341                                         tag = tag.next;
1342                                 }
1343                                 Console.WriteLine ("</line>");
1344                         }
1345                         Console.WriteLine ("</doc>");
1346                 }
1347
1348                 internal void Draw (Graphics g, Rectangle clip)
1349                 {
1350                         Line line;              // Current line being drawn
1351                         LineTag tag;            // Current tag being drawn
1352                         int start;              // First line to draw
1353                         int end;                // Last line to draw
1354                         StringBuilder text;     // String representing the current line
1355                         int line_no;
1356                         Color tag_color;
1357                         Color current_color;
1358
1359                         // First, figure out from what line to what line we need to draw
1360
1361                         if (multiline) {
1362                                 start = GetLineByPixel(clip.Top + viewport_y, false).line_no;
1363                                 end = GetLineByPixel(clip.Bottom + viewport_y, false).line_no;
1364                         } else {
1365                                 start = GetLineByPixel(clip.Left + viewport_x, false).line_no;
1366                                 end = GetLineByPixel(clip.Right + viewport_x, false).line_no;
1367                         }
1368
1369                         ///
1370                         /// We draw the single border ourself
1371                         ///
1372                         if (owner.actual_border_style == BorderStyle.FixedSingle) {
1373                                 ControlPaint.DrawBorder (g, owner.ClientRectangle, Color.Black, ButtonBorderStyle.Solid);
1374                         }
1375
1376                         /// Make sure that we aren't drawing one more line then we need to
1377                         line = GetLine (end - 1);
1378                         if (line != null && clip.Bottom == line.Y + line.height + viewport_y)
1379                                 end--;
1380
1381                         line_no = start;
1382
1383                         #if Debug
1384                                 DateTime        n = DateTime.Now;
1385                                 Console.WriteLine ("Started drawing: {0}s {1}ms", n.Second, n.Millisecond);
1386                                 Console.WriteLine ("CLIP:  {0}", clip);
1387                                 Console.WriteLine ("S: {0}", GetLine (start).text);
1388                                 Console.WriteLine ("E: {0}", GetLine (end).text);
1389                         #endif
1390
1391                         // Non multiline selection can be handled outside of the loop
1392                         if (!multiline && selection_visible && owner.ShowSelection) {
1393                                 g.FillRectangle (ThemeEngine.Current.ResPool.GetSolidBrush (ThemeEngine.Current.ColorHighlight),
1394                                                 selection_start.line.widths [selection_start.pos] +
1395                                                 selection_start.line.X - viewport_x,
1396                                                 selection_start.line.Y,
1397                                                 (selection_end.line.X + selection_end.line.widths [selection_end.pos]) -
1398                                                 (selection_start.line.X + selection_start.line.widths [selection_start.pos]),
1399                                                 selection_start.line.height);
1400                         }
1401
1402                         while (line_no <= end) {
1403                                 line = GetLine (line_no);
1404                                 float line_y = line.Y - viewport_y;
1405
1406                                 tag = line.tags;
1407                                 if (!calc_pass) {
1408                                         text = line.text;
1409                                 } else {
1410                                         if (PasswordCache.Length < line.text.Length)
1411                                                 PasswordCache.Append(Char.Parse(password_char), line.text.Length - PasswordCache.Length);
1412                                         else if (PasswordCache.Length > line.text.Length)
1413                                                 PasswordCache.Remove(line.text.Length, PasswordCache.Length - line.text.Length);
1414                                         text = PasswordCache;
1415                                 }
1416
1417                                 int line_selection_start = text.Length + 1;
1418                                 int line_selection_end = text.Length + 1;
1419                                 if (selection_visible && owner.ShowSelection &&
1420                                                 (line_no >= selection_start.line.line_no) &&
1421                                                 (line_no <= selection_end.line.line_no)) {
1422
1423                                         if (line_no == selection_start.line.line_no)
1424                                                 line_selection_start = selection_start.pos + 1;
1425                                         else
1426                                                 line_selection_start = 1;
1427
1428                                         if (line_no == selection_end.line.line_no)
1429                                                 line_selection_end = selection_end.pos + 1;
1430                                         else
1431                                                 line_selection_end = text.Length + 1;
1432
1433                                         if (line_selection_end == line_selection_start) {
1434                                                 // There isn't really selection
1435                                                 line_selection_start = text.Length + 1;
1436                                                 line_selection_end = line_selection_start;
1437                                         } else if (multiline) {
1438                                                 // lets draw some selection baby!!  (non multiline selection is drawn outside the loop)
1439                                                 g.FillRectangle (ThemeEngine.Current.ResPool.GetSolidBrush (ThemeEngine.Current.ColorHighlight),
1440                                                                 line.widths [line_selection_start - 1] + line.X - viewport_x,
1441                                                                 line_y, line.widths [line_selection_end - 1] - line.widths [line_selection_start - 1],
1442                                                                 line.height);
1443                                         }
1444                                 }
1445
1446                                 current_color = line.tags.color;
1447                                 while (tag != null) {
1448
1449                                         // Skip empty tags
1450                                         if (tag.Length == 0) {
1451                                                 tag = tag.next;
1452                                                 continue;
1453                                         }
1454
1455                                         if (((tag.X + tag.Width) < (clip.Left - viewport_x)) && (tag.X > (clip.Right - viewport_x))) {
1456                                                 tag = tag.next;
1457                                                 continue;
1458                                         }
1459
1460                                         if (tag.back_color != Color.Empty) {
1461                                                 g.FillRectangle (ThemeEngine.Current.ResPool.GetSolidBrush (tag.back_color), tag.X + line.X - viewport_x,
1462                                                                 line_y + tag.shift, tag.Width, line.height);
1463                                         }
1464
1465                                         tag_color = tag.color;
1466                                         current_color = tag_color;
1467
1468                                         if (!owner.Enabled) {
1469                                                 Color a = tag.color;
1470                                                 Color b = ThemeEngine.Current.ColorWindowText;
1471
1472                                                 if ((a.R == b.R) && (a.G == b.G) && (a.B == b.B)) {
1473                                                         tag_color = ThemeEngine.Current.ColorGrayText;
1474                                                 }
1475                                         } else if (owner.read_only && !owner.backcolor_set) {
1476                                                 tag_color = ThemeEngine.Current.ColorControlText;
1477                                         }
1478
1479                                         int tag_pos = tag.start;
1480                                         current_color = tag_color;
1481                                         while (tag_pos < tag.start + tag.Length) {
1482                                                 int old_tag_pos = tag_pos;
1483
1484                                                 if (tag_pos >= line_selection_start && tag_pos < line_selection_end) {
1485                                                         current_color = ThemeEngine.Current.ColorHighlightText;
1486                                                         tag_pos = Math.Min (tag.End, line_selection_end);
1487                                                 } else if (tag_pos < line_selection_start) {
1488                                                         current_color = tag_color;
1489                                                         tag_pos = Math.Min (tag.End, line_selection_start);
1490                                                 } else {
1491                                                         current_color = tag_color;
1492                                                         tag_pos = tag.End;
1493                                                 }
1494
1495                                                 tag.Draw (g, current_color,
1496                                                                 line.X - viewport_x,
1497                                                                 line_y + tag.shift,
1498                                                                 old_tag_pos - 1, Math.Min (tag.start + tag.Length, tag_pos) - 1,
1499                                                                 text.ToString() );
1500                                         }
1501                                         tag = tag.next;
1502                                 }
1503
1504                                 line.DrawEnding (g, line_y);
1505                                 line_no++;
1506                         }
1507                 }
1508
1509                 internal int GetLineEnding (string line, int start, out LineEnding ending)
1510                 {
1511                         int res;
1512
1513                         res = line.IndexOf ('\r', start);
1514                         if (res != -1) {
1515                                 if (res + 2 < line.Length && line [res + 1] == '\r' && line [res + 2] == '\n') {
1516                                         ending = LineEnding.Soft;
1517                                         return res;
1518                                 }
1519                                 if (res + 1 < line.Length && line [res + 1] == '\n') {
1520                                         ending = LineEnding.Hard;
1521                                         return res;
1522                                 }
1523                                 ending = LineEnding.Limp;
1524                                 return res;
1525                         }
1526
1527                         res = line.IndexOf ('\n', start);
1528                         if (res != -1) {
1529                                 ending = LineEnding.Rich;
1530                                 return res;
1531                         }
1532
1533                         ending = LineEnding.Wrap;
1534                         return line.Length;
1535                 }
1536
1537                 internal int LineEndingLength (LineEnding ending)
1538                 {
1539                         int res = 0;
1540
1541                         switch (ending) {
1542                         case LineEnding.Limp:
1543                         case LineEnding.Rich:
1544                                 res = 1;
1545                                 break;
1546                         case LineEnding.Hard:
1547                                 res = 2;
1548                                 break;
1549                         case LineEnding.Soft:
1550                                 res = 3;
1551                                 break;
1552                         }
1553
1554                         return res;
1555                 }
1556
1557                 internal string LineEndingToString (LineEnding ending)
1558                 {
1559                         string res = String.Empty;
1560                         switch (ending) {
1561                         case LineEnding.Limp:
1562                                 res = "\r";
1563                                 break;
1564                         case LineEnding.Hard:
1565                                 res = "\r\n";
1566                                 break;
1567                         case LineEnding.Soft:
1568                                 res = "\r\r\n";
1569                                 break;
1570                         case LineEnding.Rich:
1571                                 res = "\n";
1572                                 break;
1573                         }
1574                         return res;
1575                 }
1576
1577
1578                 // Insert multi-line text at the given position; use formatting at insertion point for inserted text
1579                 internal void Insert(Line line, int pos, bool update_caret, string s) {
1580                         int break_index;
1581                         int base_line;
1582                         int old_line_count;
1583                         int count = 1;
1584                         LineEnding ending;
1585                         LineTag tag = LineTag.FindTag (line, pos);
1586
1587                         SuspendRecalc ();
1588
1589                         base_line = line.line_no;
1590                         old_line_count = lines;
1591
1592                         break_index = GetLineEnding (s, 0, out ending);
1593
1594                         // Bump the text at insertion point a line down if we're inserting more than one line
1595                         if (break_index != s.Length) {
1596                                 Split (line, pos);
1597                                 line.ending = ending;
1598                                 // Remainder of start line is now in base_line + 1
1599                         }
1600
1601                         InsertString (line, pos, s.Substring (0, break_index + LineEndingLength (ending)));
1602
1603                         break_index += LineEndingLength (ending);
1604                         while (break_index < s.Length) {
1605                                 int next_break = GetLineEnding (s, break_index, out ending);
1606                                 string line_text = s.Substring (break_index, next_break - break_index +
1607                                                 LineEndingLength (ending));
1608
1609                                 Add (base_line + count, line_text, line.alignment, tag.font, tag.color, ending);
1610
1611                                 Line last = GetLine (base_line + count);
1612                                 last.ending = ending;
1613
1614                                 count++;
1615                                 break_index = next_break + LineEndingLength (ending);
1616                         }
1617
1618                         ResumeRecalc (true);
1619
1620                         UpdateView(line, lines - old_line_count + 1, pos);
1621
1622                         if (update_caret) {
1623                                 // Move caret to the end of the inserted text
1624                                 Line l = GetLine (line.line_no + lines - old_line_count);
1625                                 PositionCaret(l, l.text.Length);
1626                                 DisplayCaret ();
1627                         }
1628                 }
1629
1630                 // Inserts a character at the given position
1631                 internal void InsertString(Line line, int pos, string s) {
1632                         InsertString(line.FindTag(pos), pos, s);
1633                 }
1634
1635                 // Inserts a string at the given position
1636                 internal void InsertString(LineTag tag, int pos, string s) {
1637                         Line    line;
1638                         int     len;
1639
1640                         len = s.Length;
1641
1642                         CharCount += len;
1643
1644                         line = tag.line;
1645                         line.text.Insert(pos, s);
1646
1647                         tag = tag.next;
1648                         while (tag != null) {
1649                                 tag.start += len;
1650                                 tag = tag.next;
1651                         }
1652                         line.Grow(len);
1653                         line.recalc = true;
1654
1655                         UpdateView(line, pos);
1656                 }
1657
1658                 // Inserts a string at the caret position
1659                 internal void InsertStringAtCaret(string s, bool move_caret) {
1660
1661                         InsertString (caret.tag, caret.pos, s);
1662
1663                         UpdateView(caret.line, caret.pos);
1664                         if (move_caret) {
1665                                 caret.pos += s.Length;
1666                                 UpdateCaret();
1667                         }
1668                 }
1669
1670
1671
1672                 // Inserts a character at the given position
1673                 internal void InsertChar(Line line, int pos, char ch) {
1674                         InsertChar(line.FindTag(pos), pos, ch);
1675                 }
1676
1677                 // Inserts a character at the given position
1678                 internal void InsertChar(LineTag tag, int pos, char ch) {
1679                         Line    line;
1680
1681                         CharCount++;
1682
1683                         line = tag.line;
1684                         line.text.Insert(pos, ch);
1685
1686                         tag = tag.next;
1687                         while (tag != null) {
1688                                 tag.start++;
1689                                 tag = tag.next;
1690                         }
1691                         line.Grow(1);
1692                         line.recalc = true;
1693
1694                         undo.RecordTyping (line, pos, ch);
1695                         UpdateView(line, pos);
1696                 }
1697
1698                 // Inserts a character at the current caret position
1699                 internal void InsertCharAtCaret(char ch, bool move_caret) {
1700                         /*
1701                         LineTag tag;
1702
1703                         CharCount++;
1704
1705                         caret.line.text.Insert(caret.pos, ch);
1706                         caret.tag.length++;
1707
1708                         if (caret.tag.next != null) {
1709                                 tag = caret.tag.next;
1710                                 while (tag != null) {
1711                                         tag.start++;
1712                                         tag = tag.next;
1713                                 }
1714                         }
1715                         caret.line.Grow(1);
1716                         caret.line.recalc = true;
1717                         */
1718                         InsertChar (caret.tag, caret.pos, ch);
1719
1720                         UpdateView(caret.line, caret.pos);
1721                         if (move_caret) {
1722                                 caret.pos++;
1723                                 UpdateCaret();
1724                                 SetSelectionToCaret(true);
1725                         }
1726
1727                 }
1728
1729                 internal void InsertPicture (Line line, int pos, RTF.Picture picture)
1730                 {
1731                         //LineTag next_tag;
1732                         LineTag tag;
1733                         int len;
1734
1735                         len = 1;
1736
1737                         // Just a place holder basically
1738                         line.text.Insert (pos, "I");
1739
1740                         PictureTag picture_tag = new PictureTag (line, pos + 1, picture);
1741
1742                         tag = LineTag.FindTag (line, pos);
1743                         picture_tag.CopyFormattingFrom (tag);
1744                         /*next_tag = */tag.Break (pos + 1);
1745                         picture_tag.previous = tag;
1746                         picture_tag.next = tag.next;
1747                         tag.next = picture_tag;
1748
1749                         //
1750                         // Picture tags need to be surrounded by text tags
1751                         //
1752                         if (picture_tag.next == null) {
1753                                 picture_tag.next = new LineTag (line, pos + 1);
1754                                 picture_tag.next.CopyFormattingFrom (tag);
1755                                 picture_tag.next.previous = picture_tag;
1756                         }
1757
1758                         tag = picture_tag.next;
1759                         while (tag != null) {
1760                                 tag.start += len;
1761                                 tag = tag.next;
1762                         }
1763
1764                         line.Grow (len);
1765                         line.recalc = true;
1766
1767                         UpdateView (line, pos);
1768                 }
1769
1770                 internal void DeleteMultiline (Line start_line, int pos, int length)
1771                 {
1772                         Marker start = new Marker ();
1773                         Marker end = new Marker ();
1774                         int start_index = LineTagToCharIndex (start_line, pos);
1775
1776                         start.line = start_line;
1777                         start.pos = pos;
1778                         start.tag = LineTag.FindTag (start_line, pos);
1779
1780                         CharIndexToLineTag (start_index + length, out end.line,
1781                                         out end.tag, out end.pos);
1782
1783                         SuspendUpdate ();
1784
1785                         if (start.line == end.line) {
1786                                 DeleteChars (start.tag, pos, end.pos - pos);
1787                         } else {
1788
1789                                 // Delete first and last lines
1790                                 DeleteChars (start.tag, start.pos, start.line.text.Length - start.pos);
1791                                 DeleteChars (end.line.tags, 0, end.pos);
1792
1793                                 int current = start.line.line_no + 1;
1794                                 if (current < end.line.line_no) {
1795                                         for (int i = end.line.line_no - 1; i >= current; i--) {
1796                                                 Delete (i);
1797                                         }
1798                                 }
1799
1800                                 // BIG FAT WARNING - selection_end.line might be stale due
1801                                 // to the above Delete() call. DONT USE IT before hitting the end of this method!
1802
1803                                 // Join start and end
1804                                 Combine (start.line.line_no, current);
1805                         }
1806
1807                         ResumeUpdate (true);
1808                 }
1809
1810
1811                 // Deletes n characters at the given position; it will not delete past line limits
1812                 // pos is 0-based
1813                 internal void DeleteChars(LineTag tag, int pos, int count) {
1814                         Line    line;
1815                         bool    streamline;
1816
1817                         streamline = false;
1818                         line = tag.line;
1819
1820                         CharCount -= count;
1821
1822                         if (pos == line.text.Length) {
1823                                 return;
1824                         }
1825
1826                         line.text.Remove(pos, count);
1827
1828                         // Make sure the tag points to the right spot
1829                         while ((tag != null) && (tag.End) < pos) {
1830                                 tag = tag.next;
1831                         }
1832
1833                         if (tag == null) {
1834                                 goto Cleanup;
1835                         }
1836
1837                         // Check if we're crossing tag boundaries
1838                         if ((pos + count) > (tag.start + tag.Length - 1)) {
1839                                 int     left;
1840
1841                                 // We have to delete cross tag boundaries
1842                                 streamline = true;
1843                                 left = count;
1844
1845                                 left -= tag.start + tag.Length - pos - 1;
1846
1847                                 tag = tag.next;
1848                                 while ((tag != null) && (left > 0)) {
1849                                         tag.start -= count - left;
1850
1851                                         if (tag.Length > left) {
1852                                                 left = 0;
1853                                         } else {
1854                                                 left -= tag.Length;
1855                                                 tag = tag.next;
1856                                         }
1857
1858                                 }
1859                         } else {
1860                                 // We got off easy, same tag
1861
1862                                 if (tag.Length == 0) {
1863                                         streamline = true;
1864                                 }
1865                         }
1866
1867                         // Delete empty orphaned tags at the end
1868                         LineTag walk = tag;
1869                         while (walk != null && walk.next != null && walk.next.Length == 0) {
1870                                 LineTag t = walk;
1871                                 walk.next = walk.next.next;
1872                                 if (walk.next != null)
1873                                         walk.next.previous = t;
1874                                 walk = walk.next;
1875                         }
1876
1877                         // Adjust the start point of any tags following
1878                         if (tag != null) {
1879                                 tag = tag.next;
1880                                 while (tag != null) {
1881                                         tag.start -= count;
1882                                         tag = tag.next;
1883                                 }
1884                         }
1885
1886                         line.recalc = true;
1887                         if (streamline) {
1888                                 line.Streamline(lines);
1889                         }
1890
1891                 Cleanup:
1892                         if (pos >= line.TextLengthWithoutEnding ()) {
1893                                 LineEnding ending = line.ending;
1894                                 GetLineEnding (line.text.ToString (), 0, out ending);
1895                                 if (ending != line.ending) {
1896                                         line.ending = ending;
1897
1898                                         if (!multiline) {
1899                                                 UpdateView (line, lines, pos);
1900                                                 owner.Invalidate ();
1901                                                 return;
1902                                         }
1903                                 }
1904                         }
1905                         if (!multiline) {
1906                                 UpdateView (line, lines, pos);
1907                                 owner.Invalidate ();
1908                         } else
1909                                 UpdateView(line, pos);
1910                 }
1911
1912                 // Deletes a character at or after the given position (depending on forward); it will not delete past line limits
1913                 internal void DeleteChar(LineTag tag, int pos, bool forward) {
1914                         Line    line;
1915                         bool    streamline;
1916
1917                         CharCount--;
1918
1919                         streamline = false;
1920                         line = tag.line;
1921
1922                         if ((pos == 0 && forward == false) || (pos == line.text.Length && forward == true)) {
1923                                 return;
1924                         }
1925
1926
1927                         if (forward) {
1928                                 line.text.Remove(pos, 1);
1929
1930                                 while ((tag != null) && (tag.start + tag.Length - 1) <= pos) {
1931                                         tag = tag.next;
1932                                 }
1933
1934                                 if (tag == null) {
1935                                         goto Cleanup;
1936                                 }
1937
1938                                 //      tag.length--;
1939
1940                                 if (tag.Length == 0) {
1941                                         streamline = true;
1942                                 }
1943                         } else {
1944                                 pos--;
1945                                 line.text.Remove(pos, 1);
1946                                 if (pos >= (tag.start - 1)) {
1947                                         //              tag.length--;
1948                                         if (tag.Length == 0) {
1949                                                 streamline = true;
1950                                         }
1951                                 } else if (tag.previous != null) {
1952                                         //              tag.previous.length--;
1953                                         if (tag.previous.Length == 0) {
1954                                                 streamline = true;
1955                                         }
1956                                 }
1957                         }
1958
1959                         // Delete empty orphaned tags at the end
1960                         LineTag walk = tag;
1961                         while (walk != null && walk.next != null && walk.next.Length == 0) {
1962                                 LineTag t = walk;
1963                                 walk.next = walk.next.next;
1964                                 if (walk.next != null)
1965                                         walk.next.previous = t;
1966                                 walk = walk.next;
1967                         }
1968
1969                         tag = tag.next;
1970                         while (tag != null) {
1971                                 tag.start--;
1972                                 tag = tag.next;
1973                         }
1974                         line.recalc = true;
1975                         if (streamline) {
1976                                 line.Streamline(lines);
1977                         }
1978
1979                 Cleanup:
1980                         if (pos >= line.TextLengthWithoutEnding ()) {
1981                                 LineEnding ending = line.ending;
1982                                 GetLineEnding (line.text.ToString (), 0, out ending);
1983                                 if (ending != line.ending) {
1984                                         line.ending = ending;
1985
1986                                         if (!multiline) {
1987                                                 UpdateView (line, lines, pos);
1988                                                 owner.Invalidate ();
1989                                                 return;
1990                                         }
1991                                 }
1992                         }
1993                         if (!multiline) {
1994                                 UpdateView (line, lines, pos);
1995                                 owner.Invalidate ();
1996                         } else
1997                                 UpdateView(line, pos);
1998                 }
1999
2000                 // Combine two lines
2001                 internal void Combine(int FirstLine, int SecondLine) {
2002                         Combine(GetLine(FirstLine), GetLine(SecondLine));
2003                 }
2004
2005                 internal void Combine(Line first, Line second) {
2006                         LineTag last;
2007                         int     shift;
2008
2009                         // strip the ending off of the first lines text
2010                         first.text.Length = first.text.Length - LineEndingLength (first.ending);
2011
2012                         // Combine the two tag chains into one
2013                         last = first.tags;
2014
2015                         // Maintain the line ending style
2016                         first.ending = second.ending;
2017
2018                         while (last.next != null) {
2019                                 last = last.next;
2020                         }
2021
2022                         // need to get the shift before setting the next tag since that effects length
2023                         shift = last.start + last.Length - 1;
2024                         last.next = second.tags;
2025                         last.next.previous = last;
2026
2027                         // Fix up references within the chain
2028                         last = last.next;
2029                         while (last != null) {
2030                                 last.line = first;
2031                                 last.start += shift;
2032                                 last = last.next;
2033                         }
2034
2035                         // Combine both lines' strings
2036                         first.text.Insert(first.text.Length, second.text.ToString());
2037                         first.Grow(first.text.Length);
2038
2039                         // Remove the reference to our (now combined) tags from the doomed line
2040                         second.tags = null;
2041
2042                         // Renumber lines
2043                         DecrementLines(first.line_no + 2);      // first.line_no + 1 will be deleted, so we need to start renumbering one later
2044
2045                         // Mop up
2046                         first.recalc = true;
2047                         first.height = 0;       // This forces RecalcDocument/UpdateView to redraw from this line on
2048                         first.Streamline(lines);
2049
2050                         // Update Caret, Selection, etc
2051                         if (caret.line == second) {
2052                                 caret.Combine(first, shift);
2053                         }
2054                         if (selection_anchor.line == second) {
2055                                 selection_anchor.Combine(first, shift);
2056                         }
2057                         if (selection_start.line == second) {
2058                                 selection_start.Combine(first, shift);
2059                         }
2060                         if (selection_end.line == second) {
2061                                 selection_end.Combine(first, shift);
2062                         }
2063
2064                         #if Debug
2065                                 Line    check_first;
2066                                 Line    check_second;
2067
2068                                 check_first = GetLine(first.line_no);
2069                                 check_second = GetLine(check_first.line_no + 1);
2070
2071                                 Console.WriteLine("Pre-delete: Y of first line: {0}, second line: {1}", check_first.Y, check_second.Y);
2072                         #endif
2073
2074                         this.Delete(second);
2075
2076                         #if Debug
2077                                 check_first = GetLine(first.line_no);
2078                                 check_second = GetLine(check_first.line_no + 1);
2079
2080                                 Console.WriteLine("Post-delete Y of first line: {0}, second line: {1}", check_first.Y, check_second.Y);
2081                         #endif
2082                 }
2083
2084                 // Split the line at the position into two
2085                 internal void Split(int LineNo, int pos) {
2086                         Line    line;
2087                         LineTag tag;
2088
2089                         line = GetLine(LineNo);
2090                         tag = LineTag.FindTag(line, pos);
2091                         Split(line, tag, pos);
2092                 }
2093
2094                 internal void Split(Line line, int pos) {
2095                         LineTag tag;
2096
2097                         tag = LineTag.FindTag(line, pos);
2098                         Split(line, tag, pos);
2099                 }
2100
2101                 ///<summary>Split line at given tag and position into two lines</summary>
2102                 ///if more space becomes available on previous line</param>
2103                 internal void Split(Line line, LineTag tag, int pos) {
2104                         LineTag new_tag;
2105                         Line    new_line;
2106                         bool    move_caret;
2107                         bool    move_sel_start;
2108                         bool    move_sel_end;
2109
2110                         move_caret = false;
2111                         move_sel_start = false;
2112                         move_sel_end = false;
2113
2114                         // Adjust selection and cursors
2115                         if (caret.line == line && caret.pos >= pos) {
2116                                 move_caret = true;
2117                         }
2118                         if (selection_start.line == line && selection_start.pos > pos) {
2119                                 move_sel_start = true;
2120                         }
2121
2122                         if (selection_end.line == line && selection_end.pos > pos) {
2123                                 move_sel_end = true;
2124                         }
2125
2126                         // cover the easy case first
2127                         if (pos == line.text.Length) {
2128                                 Add (line.line_no + 1, String.Empty, line.alignment, tag.font, tag.color, line.ending);
2129
2130                                 new_line = GetLine (line.line_no + 1);
2131
2132                                 if (move_caret) {
2133                                         caret.line = new_line;
2134                                         caret.tag = new_line.tags;
2135                                         caret.pos = 0;
2136                                 }
2137
2138                                 if (move_sel_start) {
2139                                         selection_start.line = new_line;
2140                                         selection_start.pos = 0;
2141                                         selection_start.tag = new_line.tags;
2142                                 }
2143
2144                                 if (move_sel_end) {
2145                                         selection_end.line = new_line;
2146                                         selection_end.pos = 0;
2147                                         selection_end.tag = new_line.tags;
2148                                 }
2149                                 return;
2150                         }
2151
2152                         // We need to move the rest of the text into the new line
2153                         Add (line.line_no + 1, line.text.ToString (pos, line.text.Length - pos), line.alignment, tag.font, tag.color, line.ending);
2154
2155                         // Now transfer our tags from this line to the next
2156                         new_line = GetLine(line.line_no + 1);
2157
2158                         line.recalc = true;
2159                         new_line.recalc = true;
2160
2161                         if ((tag.start - 1) == pos) {
2162                                 int     shift;
2163
2164                                 // We can simply break the chain and move the tag into the next line
2165                                 if (tag == line.tags) {
2166                                         new_tag = new LineTag(line, 1);
2167                                         new_tag.CopyFormattingFrom (tag);
2168                                         line.tags = new_tag;
2169                                 }
2170
2171                                 if (tag.previous != null) {
2172                                         tag.previous.next = null;
2173                                 }
2174                                 new_line.tags = tag;
2175                                 tag.previous = null;
2176                                 tag.line = new_line;
2177
2178                                 // Walk the list and correct the start location of the tags we just bumped into the next line
2179                                 shift = tag.start - 1;
2180
2181                                 new_tag = tag;
2182                                 while (new_tag != null) {
2183                                         new_tag.start -= shift;
2184                                         new_tag.line = new_line;
2185                                         new_tag = new_tag.next;
2186                                 }
2187                         } else {
2188                                 int     shift;
2189
2190                                 new_tag = new LineTag (new_line, 1);
2191                                 new_tag.next = tag.next;
2192                                 new_tag.CopyFormattingFrom (tag);
2193                                 new_line.tags = new_tag;
2194                                 if (new_tag.next != null) {
2195                                         new_tag.next.previous = new_tag;
2196                                 }
2197                                 tag.next = null;
2198
2199                                 shift = pos;
2200                                 new_tag = new_tag.next;
2201                                 while (new_tag != null) {
2202                                         new_tag.start -= shift;
2203                                         new_tag.line = new_line;
2204                                         new_tag = new_tag.next;
2205
2206                                 }
2207                         }
2208
2209                         if (move_caret) {
2210                                 caret.line = new_line;
2211                                 caret.pos = caret.pos - pos;
2212                                 caret.tag = caret.line.FindTag(caret.pos);
2213                         }
2214
2215                         if (move_sel_start) {
2216                                 selection_start.line = new_line;
2217                                 selection_start.pos = selection_start.pos - pos;
2218                                 selection_start.tag = new_line.FindTag(selection_start.pos);
2219                         }
2220
2221                         if (move_sel_end) {
2222                                 selection_end.line = new_line;
2223                                 selection_end.pos = selection_end.pos - pos;
2224                                 selection_end.tag = new_line.FindTag(selection_end.pos);
2225                         }
2226
2227                         CharCount -= line.text.Length - pos;
2228                         line.text.Remove(pos, line.text.Length - pos);
2229                 }
2230
2231                 // Adds a line of text, with given font.
2232                 // Bumps any line at that line number that already exists down
2233                 internal void Add (int LineNo, string Text, Font font, Color color, LineEnding ending)
2234                 {
2235                         Add (LineNo, Text, alignment, font, color, ending);
2236                 }
2237
2238                 internal void Add (int LineNo, string Text, HorizontalAlignment align, Font font, Color color, LineEnding ending)
2239                 {
2240                         Line    add;
2241                         Line    line;
2242                         int     line_no;
2243
2244                         CharCount += Text.Length;
2245
2246                         if (LineNo<1 || Text == null) {
2247                                 if (LineNo<1) {
2248                                         throw new ArgumentNullException("LineNo", "Line numbers must be positive");
2249                                 } else {
2250                                         throw new ArgumentNullException("Text", "Cannot insert NULL line");
2251                                 }
2252                         }
2253
2254                         add = new Line (this, LineNo, Text, align, font, color, ending);
2255
2256                         line = document;
2257                         while (line != sentinel) {
2258                                 add.parent = line;
2259                                 line_no = line.line_no;
2260
2261                                 if (LineNo > line_no) {
2262                                         line = line.right;
2263                                 } else if (LineNo < line_no) {
2264                                         line = line.left;
2265                                 } else {
2266                                         // Bump existing line numbers; walk all nodes to the right of this one and increment line_no
2267                                         IncrementLines(line.line_no);
2268                                         line = line.left;
2269                                 }
2270                         }
2271
2272                         add.left = sentinel;
2273                         add.right = sentinel;
2274
2275                         if (add.parent != null) {
2276                                 if (LineNo > add.parent.line_no) {
2277                                         add.parent.right = add;
2278                                 } else {
2279                                         add.parent.left = add;
2280                                 }
2281                         } else {
2282                                 // Root node
2283                                 document = add;
2284                         }
2285
2286                         RebalanceAfterAdd(add);
2287
2288                         lines++;
2289                 }
2290
2291                 internal virtual void Clear() {
2292                         lines = 0;
2293                         CharCount = 0;
2294                         document = sentinel;
2295                 }
2296
2297                 public virtual object Clone() {
2298                         Document clone;
2299
2300                         clone = new Document(null);
2301
2302                         clone.lines = this.lines;
2303                         clone.document = (Line)document.Clone();
2304
2305                         return clone;
2306                 }
2307
2308                 internal void Delete(int LineNo) {
2309                         Line    line;
2310
2311                         if (LineNo>lines) {
2312                                 return;
2313                         }
2314
2315                         line = GetLine(LineNo);
2316
2317                         CharCount -= line.text.Length;
2318
2319                         DecrementLines(LineNo + 1);
2320                         Delete(line);
2321                 }
2322
2323                 internal void Delete(Line line1) {
2324                         Line    line2;// = new Line();
2325                         Line    line3;
2326
2327                         if ((line1.left == sentinel) || (line1.right == sentinel)) {
2328                                 line3 = line1;
2329                         } else {
2330                                 line3 = line1.right;
2331                                 while (line3.left != sentinel) {
2332                                         line3 = line3.left;
2333                                 }
2334                         }
2335
2336                         if (line3.left != sentinel) {
2337                                 line2 = line3.left;
2338                         } else {
2339                                 line2 = line3.right;
2340                         }
2341
2342                         line2.parent = line3.parent;
2343                         if (line3.parent != null) {
2344                                 if(line3 == line3.parent.left) {
2345                                         line3.parent.left = line2;
2346                                 } else {
2347                                         line3.parent.right = line2;
2348                                 }
2349                         } else {
2350                                 document = line2;
2351                         }
2352
2353                         if (line3 != line1) {
2354                                 LineTag tag;
2355
2356                                 if (selection_start.line == line3) {
2357                                         selection_start.line = line1;
2358                                 }
2359
2360                                 if (selection_end.line == line3) {
2361                                         selection_end.line = line1;
2362                                 }
2363
2364                                 if (selection_anchor.line == line3) {
2365                                         selection_anchor.line = line1;
2366                                 }
2367
2368                                 if (caret.line == line3) {
2369                                         caret.line = line1;
2370                                 }
2371
2372
2373                                 line1.alignment = line3.alignment;
2374                                 line1.ascent = line3.ascent;
2375                                 line1.hanging_indent = line3.hanging_indent;
2376                                 line1.height = line3.height;
2377                                 line1.indent = line3.indent;
2378                                 line1.line_no = line3.line_no;
2379                                 line1.recalc = line3.recalc;
2380                                 line1.right_indent = line3.right_indent;
2381                                 line1.ending = line3.ending;
2382                                 line1.space = line3.space;
2383                                 line1.tags = line3.tags;
2384                                 line1.text = line3.text;
2385                                 line1.widths = line3.widths;
2386                                 line1.offset = line3.offset;
2387
2388                                 tag = line1.tags;
2389                                 while (tag != null) {
2390                                         tag.line = line1;
2391                                         tag = tag.next;
2392                                 }
2393                         }
2394
2395                         if (line3.color == LineColor.Black)
2396                                 RebalanceAfterDelete(line2);
2397
2398                         this.lines--;
2399                 }
2400
2401                 // Invalidate a section of the document to trigger redraw
2402                 internal void Invalidate(Line start, int start_pos, Line end, int end_pos) {
2403                         Line    l1;
2404                         Line    l2;
2405                         int     p1;
2406                         int     p2;
2407
2408                         if ((start == end) && (start_pos == end_pos)) {
2409                                 return;
2410                         }
2411
2412                         if (end_pos == -1) {
2413                                 end_pos = end.text.Length;
2414                         }
2415
2416                         // figure out what's before what so the logic below is straightforward
2417                         if (start.line_no < end.line_no) {
2418                                 l1 = start;
2419                                 p1 = start_pos;
2420
2421                                 l2 = end;
2422                                 p2 = end_pos;
2423                         } else if (start.line_no > end.line_no) {
2424                                 l1 = end;
2425                                 p1 = end_pos;
2426
2427                                 l2 = start;
2428                                 p2 = start_pos;
2429                         } else {
2430                                 if (start_pos < end_pos) {
2431                                         l1 = start;
2432                                         p1 = start_pos;
2433
2434                                         l2 = end;
2435                                         p2 = end_pos;
2436                                 } else {
2437                                         l1 = end;
2438                                         p1 = end_pos;
2439
2440                                         l2 = start;
2441                                         p2 = start_pos;
2442                                 }
2443
2444                                 int endpoint = (int) l1.widths [p2];
2445                                 if (p2 == l1.text.Length + 1) {
2446                                         endpoint = (int) viewport_width;
2447                                 }
2448
2449                                 #if Debug
2450                                         Console.WriteLine("Invaliding backwards from {0}:{1} to {2}:{3}   {4}",
2451                                                         l1.line_no, p1, l2.line_no, p2,
2452                                                         new Rectangle(
2453                                                                 (int)l1.widths[p1] + l1.X - viewport_x,
2454                                                                 l1.Y - viewport_y,
2455                                                                 (int)l1.widths[p2],
2456                                                                 l1.height
2457                                                                 )
2458                                                 );
2459                                 #endif
2460
2461                                 owner.Invalidate(new Rectangle (
2462                                         (int)l1.widths[p1] + l1.X - viewport_x,
2463                                         l1.Y - viewport_y,
2464                                         endpoint - (int)l1.widths[p1] + 1,
2465                                         l1.height));
2466                                 return;
2467                         }
2468
2469                         #if Debug
2470                                 Console.WriteLine("Invaliding from {0}:{1} to {2}:{3} Start  => x={4}, y={5}, {6}x{7}", l1.line_no, p1, l2.line_no, p2, (int)l1.widths[p1] + l1.X - viewport_x, l1.Y - viewport_y, viewport_width, l1.height);
2471                                 Console.WriteLine ("invalidate start line:  {0}  position:  {1}", l1.text, p1);
2472                         #endif
2473
2474                         // Three invalidates:
2475                         // First line from start
2476                         owner.Invalidate(new Rectangle((int)l1.widths[p1] + l1.X - viewport_x, l1.Y - viewport_y, viewport_width, l1.height));
2477
2478
2479                         // lines inbetween
2480                         if ((l1.line_no + 1) < l2.line_no) {
2481                                 int     y;
2482
2483                                 y = GetLine(l1.line_no + 1).Y;
2484                                 owner.Invalidate(new Rectangle(0, y - viewport_y, viewport_width, l2.Y - y));
2485
2486                                 #if Debug
2487                                         Console.WriteLine("Invaliding from {0}:{1} to {2}:{3} Middle => x={4}, y={5}, {6}x{7}", l1.line_no, p1, l2.line_no, p2, 0, y - viewport_y, viewport_width, l2.Y - y);
2488                                 #endif
2489                         }
2490
2491
2492                         // Last line to end
2493                         owner.Invalidate(new Rectangle((int)l2.widths[0] + l2.X - viewport_x, l2.Y - viewport_y, (int)l2.widths[p2] + 1, l2.height));
2494                         #if Debug
2495                                 Console.WriteLine("Invaliding from {0}:{1} to {2}:{3} End    => x={4}, y={5}, {6}x{7}", l1.line_no, p1, l2.line_no, p2, (int)l2.widths[0] + l2.X - viewport_x, l2.Y - viewport_y, (int)l2.widths[p2] + 1, l2.height);
2496
2497                         #endif
2498                 }
2499
2500                 /// <summary>Select text around caret</summary>
2501                 internal void ExpandSelection(CaretSelection mode, bool to_caret) {
2502                         if (to_caret) {
2503                                 // We're expanding the selection to the caret position
2504                                 switch(mode) {
2505                                         case CaretSelection.Line: {
2506                                                 // Invalidate the selection delta
2507                                                 if (caret > selection_prev) {
2508                                                         Invalidate(selection_prev.line, 0, caret.line, caret.line.text.Length);
2509                                                 } else {
2510                                                         Invalidate(selection_prev.line, selection_prev.line.text.Length, caret.line, 0);
2511                                                 }
2512
2513                                                 if (caret.line.line_no <= selection_anchor.line.line_no) {
2514                                                         selection_start.line = caret.line;
2515                                                         selection_start.tag = caret.line.tags;
2516                                                         selection_start.pos = 0;
2517
2518                                                         selection_end.line = selection_anchor.line;
2519                                                         selection_end.tag = selection_anchor.tag;
2520                                                         selection_end.pos = selection_anchor.pos;
2521
2522                                                         selection_end_anchor = true;
2523                                                 } else {
2524                                                         selection_start.line = selection_anchor.line;
2525                                                         selection_start.pos = selection_anchor.height;
2526                                                         selection_start.tag = selection_anchor.line.FindTag(selection_anchor.height);
2527
2528                                                         selection_end.line = caret.line;
2529                                                         selection_end.tag = caret.line.tags;
2530                                                         selection_end.pos = caret.line.text.Length;
2531
2532                                                         selection_end_anchor = false;
2533                                                 }
2534                                                 selection_prev.line = caret.line;
2535                                                 selection_prev.tag = caret.tag;
2536                                                 selection_prev.pos = caret.pos;
2537
2538                                                 break;
2539                                         }
2540
2541                                         case CaretSelection.Word: {
2542                                                 int     start_pos;
2543                                                 int     end_pos;
2544
2545                                                 start_pos = FindWordSeparator(caret.line, caret.pos, false);
2546                                                 end_pos = FindWordSeparator(caret.line, caret.pos, true);
2547
2548
2549                                                 // Invalidate the selection delta
2550                                                 if (caret > selection_prev) {
2551                                                         Invalidate(selection_prev.line, selection_prev.pos, caret.line, end_pos);
2552                                                 } else {
2553                                                         Invalidate(selection_prev.line, selection_prev.pos, caret.line, start_pos);
2554                                                 }
2555                                                 if (caret < selection_anchor) {
2556                                                         selection_start.line = caret.line;
2557                                                         selection_start.tag = caret.line.FindTag(start_pos);
2558                                                         selection_start.pos = start_pos;
2559
2560                                                         selection_end.line = selection_anchor.line;
2561                                                         selection_end.tag = selection_anchor.tag;
2562                                                         selection_end.pos = selection_anchor.pos;
2563
2564                                                         selection_prev.line = caret.line;
2565                                                         selection_prev.tag = caret.tag;
2566                                                         selection_prev.pos = start_pos;
2567
2568                                                         selection_end_anchor = true;
2569                                                 } else {
2570                                                         selection_start.line = selection_anchor.line;
2571                                                         selection_start.pos = selection_anchor.height;
2572                                                         selection_start.tag = selection_anchor.line.FindTag(selection_anchor.height);
2573
2574                                                         selection_end.line = caret.line;
2575                                                         selection_end.tag = caret.line.FindTag(end_pos);
2576                                                         selection_end.pos = end_pos;
2577
2578                                                         selection_prev.line = caret.line;
2579                                                         selection_prev.tag = caret.tag;
2580                                                         selection_prev.pos = end_pos;
2581
2582                                                         selection_end_anchor = false;
2583                                                 }
2584                                                 break;
2585                                         }
2586
2587                                         case CaretSelection.Position: {
2588                                                 SetSelectionToCaret(false);
2589                                                 return;
2590                                         }
2591                                 }
2592                         } else {
2593                                 // We're setting the selection 'around' the caret position
2594                                 switch(mode) {
2595                                         case CaretSelection.Line: {
2596                                                 this.Invalidate(caret.line, 0, caret.line, caret.line.text.Length);
2597
2598                                                 selection_start.line = caret.line;
2599                                                 selection_start.tag = caret.line.tags;
2600                                                 selection_start.pos = 0;
2601
2602                                                 selection_end.line = caret.line;
2603                                                 selection_end.pos = caret.line.text.Length;
2604                                                 selection_end.tag = caret.line.FindTag(selection_end.pos);
2605
2606                                                 selection_anchor.line = selection_end.line;
2607                                                 selection_anchor.tag = selection_end.tag;
2608                                                 selection_anchor.pos = selection_end.pos;
2609                                                 selection_anchor.height = 0;
2610
2611                                                 selection_prev.line = caret.line;
2612                                                 selection_prev.tag = caret.tag;
2613                                                 selection_prev.pos = caret.pos;
2614
2615                                                 this.selection_end_anchor = true;
2616
2617                                                 break;
2618                                         }
2619
2620                                         case CaretSelection.Word: {
2621                                                 int     start_pos;
2622                                                 int     end_pos;
2623
2624                                                 start_pos = FindWordSeparator(caret.line, caret.pos, false);
2625                                                 end_pos = FindWordSeparator(caret.line, caret.pos, true);
2626
2627                                                 this.Invalidate(selection_start.line, start_pos, caret.line, end_pos);
2628
2629                                                 selection_start.line = caret.line;
2630                                                 selection_start.tag = caret.line.FindTag(start_pos);
2631                                                 selection_start.pos = start_pos;
2632
2633                                                 selection_end.line = caret.line;
2634                                                 selection_end.tag = caret.line.FindTag(end_pos);
2635                                                 selection_end.pos = end_pos;
2636
2637                                                 selection_anchor.line = selection_end.line;
2638                                                 selection_anchor.tag = selection_end.tag;
2639                                                 selection_anchor.pos = selection_end.pos;
2640                                                 selection_anchor.height = start_pos;
2641
2642                                                 selection_prev.line = caret.line;
2643                                                 selection_prev.tag = caret.tag;
2644                                                 selection_prev.pos = caret.pos;
2645
2646                                                 this.selection_end_anchor = true;
2647
2648                                                 break;
2649                                         }
2650                                 }
2651                         }
2652
2653                         SetSelectionVisible (!(selection_start == selection_end));
2654                 }
2655
2656                 internal void SetSelectionToCaret(bool start) {
2657                         if (start) {
2658                                 // Invalidate old selection; selection is being reset to empty
2659                                 this.Invalidate(selection_start.line, selection_start.pos, selection_end.line, selection_end.pos);
2660
2661                                 selection_start.line = caret.line;
2662                                 selection_start.tag = caret.tag;
2663                                 selection_start.pos = caret.pos;
2664
2665                                 // start always also selects end
2666                                 selection_end.line = caret.line;
2667                                 selection_end.tag = caret.tag;
2668                                 selection_end.pos = caret.pos;
2669
2670                                 selection_anchor.line = caret.line;
2671                                 selection_anchor.tag = caret.tag;
2672                                 selection_anchor.pos = caret.pos;
2673                         } else {
2674                                 // Invalidate from previous end to caret (aka new end)
2675                                 if (selection_end_anchor) {
2676                                         if (selection_start != caret) {
2677                                                 this.Invalidate(selection_start.line, selection_start.pos, caret.line, caret.pos);
2678                                         }
2679                                 } else {
2680                                         if (selection_end != caret) {
2681                                                 this.Invalidate(selection_end.line, selection_end.pos, caret.line, caret.pos);
2682                                         }
2683                                 }
2684
2685                                 if (caret < selection_anchor) {
2686                                         selection_start.line = caret.line;
2687                                         selection_start.tag = caret.tag;
2688                                         selection_start.pos = caret.pos;
2689
2690                                         selection_end.line = selection_anchor.line;
2691                                         selection_end.tag = selection_anchor.tag;
2692                                         selection_end.pos = selection_anchor.pos;
2693
2694                                         selection_end_anchor = true;
2695                                 } else {
2696                                         selection_start.line = selection_anchor.line;
2697                                         selection_start.tag = selection_anchor.tag;
2698                                         selection_start.pos = selection_anchor.pos;
2699
2700                                         selection_end.line = caret.line;
2701                                         selection_end.tag = caret.tag;
2702                                         selection_end.pos = caret.pos;
2703
2704                                         selection_end_anchor = false;
2705                                 }
2706                         }
2707
2708                         SetSelectionVisible (!(selection_start == selection_end));
2709                 }
2710
2711                 internal void SetSelection(Line start, int start_pos, Line end, int end_pos) {
2712                         if (selection_visible) {
2713                                 Invalidate(selection_start.line, selection_start.pos, selection_end.line, selection_end.pos);
2714                         }
2715
2716                         if ((end.line_no < start.line_no) || ((end == start) && (end_pos <= start_pos))) {
2717                                 selection_start.line = end;
2718                                 selection_start.tag = LineTag.FindTag(end, end_pos);
2719                                 selection_start.pos = end_pos;
2720
2721                                 selection_end.line = start;
2722                                 selection_end.tag = LineTag.FindTag(start, start_pos);
2723                                 selection_end.pos = start_pos;
2724
2725                                 selection_end_anchor = true;
2726                         } else {
2727                                 selection_start.line = start;
2728                                 selection_start.tag = LineTag.FindTag(start, start_pos);
2729                                 selection_start.pos = start_pos;
2730
2731                                 selection_end.line = end;
2732                                 selection_end.tag = LineTag.FindTag(end, end_pos);
2733                                 selection_end.pos = end_pos;
2734
2735                                 selection_end_anchor = false;
2736                         }
2737
2738                         selection_anchor.line = start;
2739                         selection_anchor.tag = selection_start.tag;
2740                         selection_anchor.pos = start_pos;
2741
2742                         if (((start == end) && (start_pos == end_pos)) || start == null || end == null) {
2743                                 SetSelectionVisible (false);
2744                         } else {
2745                                 SetSelectionVisible (true);
2746                                 Invalidate(selection_start.line, selection_start.pos, selection_end.line, selection_end.pos);
2747                         }
2748                 }
2749
2750                 internal void SetSelectionStart(Line start, int start_pos, bool invalidate) {
2751                         // Invalidate from the previous to the new start pos
2752                         if (invalidate)
2753                                 Invalidate(selection_start.line, selection_start.pos, start, start_pos);
2754
2755                         selection_start.line = start;
2756                         selection_start.pos = start_pos;
2757                         selection_start.tag = LineTag.FindTag(start, start_pos);
2758
2759                         selection_anchor.line = start;
2760                         selection_anchor.pos = start_pos;
2761                         selection_anchor.tag = selection_start.tag;
2762
2763                         selection_end_anchor = false;
2764
2765
2766                         if ((selection_end.line != selection_start.line) || (selection_end.pos != selection_start.pos)) {
2767                                 SetSelectionVisible (true);
2768                         } else {
2769                                 SetSelectionVisible (false);
2770                         }
2771
2772                         if (invalidate)
2773                                 Invalidate(selection_start.line, selection_start.pos, selection_end.line, selection_end.pos);
2774                 }
2775
2776                 internal void SetSelectionStart(int character_index, bool invalidate) {
2777                         Line    line;
2778                         LineTag tag;
2779                         int     pos;
2780
2781                         if (character_index < 0) {
2782                                 return;
2783                         }
2784
2785                         CharIndexToLineTag(character_index, out line, out tag, out pos);
2786                         SetSelectionStart(line, pos, invalidate);
2787                 }
2788
2789                 internal void SetSelectionEnd(Line end, int end_pos, bool invalidate) {
2790
2791                         if (end == selection_end.line && end_pos == selection_start.pos) {
2792                                 selection_anchor.line = selection_start.line;
2793                                 selection_anchor.tag = selection_start.tag;
2794                                 selection_anchor.pos = selection_start.pos;
2795
2796                                 selection_end.line = selection_start.line;
2797                                 selection_end.tag = selection_start.tag;
2798                                 selection_end.pos = selection_start.pos;
2799
2800                                 selection_end_anchor = false;
2801                         } else if ((end.line_no < selection_anchor.line.line_no) || ((end == selection_anchor.line) && (end_pos <= selection_anchor.pos))) {
2802                                 selection_start.line = end;
2803                                 selection_start.tag = LineTag.FindTag(end, end_pos);
2804                                 selection_start.pos = end_pos;
2805
2806                                 selection_end.line = selection_anchor.line;
2807                                 selection_end.tag = selection_anchor.tag;
2808                                 selection_end.pos = selection_anchor.pos;
2809
2810                                 selection_end_anchor = true;
2811                         } else {
2812                                 selection_start.line = selection_anchor.line;
2813                                 selection_start.tag = selection_anchor.tag;
2814                                 selection_start.pos = selection_anchor.pos;
2815
2816                                 selection_end.line = end;
2817                                 selection_end.tag = LineTag.FindTag(end, end_pos);
2818                                 selection_end.pos = end_pos;
2819
2820                                 selection_end_anchor = false;
2821                         }
2822
2823                         if ((selection_end.line != selection_start.line) || (selection_end.pos != selection_start.pos)) {
2824                                 SetSelectionVisible (true);
2825                                 if (invalidate)
2826                                         Invalidate(selection_start.line, selection_start.pos, selection_end.line, selection_end.pos);
2827                         } else {
2828                                 SetSelectionVisible (false);
2829                                 // ?? Do I need to invalidate here, tests seem to work without it, but I don't think they should :-s
2830                         }
2831                 }
2832
2833                 internal void SetSelectionEnd(int character_index, bool invalidate) {
2834                         Line    line;
2835                         LineTag tag;
2836                         int     pos;
2837
2838                         if (character_index < 0) {
2839                                 return;
2840                         }
2841
2842                         CharIndexToLineTag(character_index, out line, out tag, out pos);
2843                         SetSelectionEnd(line, pos, invalidate);
2844                 }
2845
2846                 internal void SetSelection(Line start, int start_pos) {
2847                         if (selection_visible) {
2848                                 Invalidate(selection_start.line, selection_start.pos, selection_end.line, selection_end.pos);
2849                         }
2850
2851                         selection_start.line = start;
2852                         selection_start.pos = start_pos;
2853                         selection_start.tag = LineTag.FindTag(start, start_pos);
2854
2855                         selection_end.line = start;
2856                         selection_end.tag = selection_start.tag;
2857                         selection_end.pos = start_pos;
2858
2859                         selection_anchor.line = start;
2860                         selection_anchor.tag = selection_start.tag;
2861                         selection_anchor.pos = start_pos;
2862
2863                         selection_end_anchor = false;
2864                         SetSelectionVisible (false);
2865                 }
2866
2867                 internal void InvalidateSelectionArea() {
2868                         Invalidate (selection_start.line, selection_start.pos, selection_end.line, selection_end.pos);
2869                 }
2870
2871                 // Return the current selection, as string
2872                 internal string GetSelection() {
2873                         // We return String.Empty if there is no selection
2874                         if ((selection_start.pos == selection_end.pos) && (selection_start.line == selection_end.line)) {
2875                                 return string.Empty;
2876                         }
2877
2878                         if (selection_start.line == selection_end.line) {
2879                                 return selection_start.line.text.ToString (selection_start.pos, selection_end.pos - selection_start.pos);
2880                         } else {
2881                                 StringBuilder   sb;
2882                                 int             i;
2883                                 int             start;
2884                                 int             end;
2885
2886                                 sb = new StringBuilder();
2887                                 start = selection_start.line.line_no;
2888                                 end = selection_end.line.line_no;
2889
2890                                 sb.Append(selection_start.line.text.ToString(selection_start.pos, selection_start.line.text.Length - selection_start.pos) + Environment.NewLine);
2891
2892                                 if ((start + 1) < end) {
2893                                         for (i = start + 1; i < end; i++) {
2894                                                 sb.Append(GetLine(i).text.ToString() + Environment.NewLine);
2895                                         }
2896                                 }
2897
2898                                 sb.Append(selection_end.line.text.ToString(0, selection_end.pos));
2899
2900                                 return sb.ToString();
2901                         }
2902                 }
2903
2904                 internal void ReplaceSelection(string s, bool select_new) {
2905                         int             i;
2906
2907                         int selection_pos_on_line = selection_start.pos;
2908                         int selection_start_pos = LineTagToCharIndex (selection_start.line, selection_start.pos);
2909                         SuspendRecalc ();
2910
2911                         // First, delete any selected text
2912                         if ((selection_start.pos != selection_end.pos) || (selection_start.line != selection_end.line)) {
2913                                 if (selection_start.line == selection_end.line) {
2914                                         undo.RecordDeleteString (selection_start.line, selection_start.pos, selection_end.line, selection_end.pos);
2915
2916                                         DeleteChars(selection_start.tag, selection_start.pos, selection_end.pos - selection_start.pos);
2917
2918                                         // The tag might have been removed, we need to recalc it
2919                                         selection_start.tag = selection_start.line.FindTag(selection_start.pos);
2920                                 } else {
2921                                         int             start;
2922                                         int             end;
2923
2924                                         start = selection_start.line.line_no;
2925                                         end = selection_end.line.line_no;
2926
2927                                         undo.RecordDeleteString (selection_start.line, selection_start.pos, selection_end.line, selection_end.pos);
2928
2929                                         InvalidateSelectionArea ();
2930
2931                                         // Delete first line
2932                                         DeleteChars(selection_start.tag, selection_start.pos, selection_start.line.text.Length - selection_start.pos);
2933                                         selection_start.line.recalc = true;
2934
2935                                         // Delete last line
2936                                         DeleteChars(selection_end.line.tags, 0, selection_end.pos);
2937
2938                                         start++;
2939                                         if (start < end) {
2940                                                 for (i = end - 1; i >= start; i--) {
2941                                                         Delete(i);
2942                                                 }
2943                                         }
2944
2945                                         // BIG FAT WARNING - selection_end.line might be stale due
2946                                         // to the above Delete() call. DONT USE IT before hitting the end of this method!
2947
2948                                         // Join start and end
2949                                         Combine(selection_start.line.line_no, start);
2950                                 }
2951                         }
2952
2953
2954                         Insert(selection_start.line, selection_start.pos, false, s);
2955                         undo.RecordInsertString (selection_start.line, selection_start.pos, s);
2956                         ResumeRecalc (false);
2957
2958                         if (!select_new) {
2959                                 CharIndexToLineTag(selection_start_pos + s.Length, out selection_start.line,
2960                                                 out selection_start.tag, out selection_start.pos);
2961
2962                                 selection_end.line = selection_start.line;
2963                                 selection_end.pos = selection_start.pos;
2964                                 selection_end.tag = selection_start.tag;
2965                                 selection_anchor.line = selection_start.line;
2966                                 selection_anchor.pos = selection_start.pos;
2967                                 selection_anchor.tag = selection_start.tag;
2968
2969                                 SetSelectionVisible (false);
2970                         } else {
2971                                 CharIndexToLineTag(selection_start_pos, out selection_start.line,
2972                                                 out selection_start.tag, out selection_start.pos);
2973
2974                                 CharIndexToLineTag(selection_start_pos + s.Length, out selection_end.line,
2975                                                 out selection_end.tag, out selection_end.pos);
2976
2977                                 selection_anchor.line = selection_start.line;
2978                                 selection_anchor.pos = selection_start.pos;
2979                                 selection_anchor.tag = selection_start.tag;
2980
2981                                 SetSelectionVisible (true);
2982                         }
2983
2984                         PositionCaret (selection_start.line, selection_start.pos);
2985                         UpdateView (selection_start.line, selection_pos_on_line);
2986                 }
2987
2988                 internal void CharIndexToLineTag(int index, out Line line_out, out LineTag tag_out, out int pos) {
2989                         Line    line;
2990                         LineTag tag;
2991                         int     i;
2992                         int     chars;
2993                         int     start;
2994
2995                         chars = 0;
2996
2997                         for (i = 1; i <= lines; i++) {
2998                                 line = GetLine(i);
2999
3000                                 start = chars;
3001                                 chars += line.text.Length;
3002
3003                                 if (index <= chars) {
3004                                         // we found the line
3005                                         tag = line.tags;
3006
3007                                         while (tag != null) {
3008                                                 if (index < (start + tag.start + tag.Length - 1)) {
3009                                                         line_out = line;
3010                                                         tag_out = LineTag.GetFinalTag (tag);
3011                                                         pos = index - start;
3012                                                         return;
3013                                                 }
3014                                                 if (tag.next == null) {
3015                                                         Line    next_line;
3016
3017                                                         next_line = GetLine(line.line_no + 1);
3018
3019                                                         if (next_line != null) {
3020                                                                 line_out = next_line;
3021                                                                 tag_out = LineTag.GetFinalTag (next_line.tags);
3022                                                                 pos = 0;
3023                                                                 return;
3024                                                         } else {
3025                                                                 line_out = line;
3026                                                                 tag_out = LineTag.GetFinalTag (tag);
3027                                                                 pos = line_out.text.Length;
3028                                                                 return;
3029                                                         }
3030                                                 }
3031                                                 tag = tag.next;
3032                                         }
3033                                 }
3034                         }
3035
3036                         line_out = GetLine(lines);
3037                         tag = line_out.tags;
3038                         while (tag.next != null) {
3039                                 tag = tag.next;
3040                         }
3041                         tag_out = tag;
3042                         pos = line_out.text.Length;
3043                 }
3044
3045                 internal int LineTagToCharIndex(Line line, int pos) {
3046                         int     i;
3047                         int     length;
3048
3049                         // Count first and last line
3050                         length = 0;
3051
3052                         // Count the lines in the middle
3053
3054                         for (i = 1; i < line.line_no; i++) {
3055                                 length += GetLine(i).text.Length;
3056                         }
3057
3058                         length += pos;
3059
3060                         return length;
3061                 }
3062
3063                 internal int SelectionLength() {
3064                         if ((selection_start.pos == selection_end.pos) && (selection_start.line == selection_end.line)) {
3065                                 return 0;
3066                         }
3067
3068                         if (selection_start.line == selection_end.line) {
3069                                 return selection_end.pos - selection_start.pos;
3070                         } else {
3071                                 int     i;
3072                                 int     start;
3073                                 int     end;
3074                                 int     length;
3075
3076                                 // Count first and last line
3077                                 length = selection_start.line.text.Length - selection_start.pos + selection_end.pos + crlf_size;
3078
3079                                 // Count the lines in the middle
3080                                 start = selection_start.line.line_no + 1;
3081                                 end = selection_end.line.line_no;
3082
3083                                 if (start < end) {
3084                                         for (i = start; i < end; i++) {
3085                                                 Line line = GetLine (i);
3086                                                 length += line.text.Length + LineEndingLength (line.ending);
3087                                         }
3088                                 }
3089
3090                                 return length;
3091                         }
3092
3093
3094                 }
3095
3096
3097                 /// <summary>Give it a Line number and it returns the Line object at with that line number</summary>
3098                 internal Line GetLine(int LineNo) {
3099                         Line    line = document;
3100
3101                         while (line != sentinel) {
3102                                 if (LineNo == line.line_no) {
3103                                         return line;
3104                                 } else if (LineNo < line.line_no) {
3105                                         line = line.left;
3106                                 } else {
3107                                         line = line.right;
3108                                 }
3109                         }
3110
3111                         return null;
3112                 }
3113
3114                 /// <summary>Retrieve the previous tag; walks line boundaries</summary>
3115                 internal LineTag PreviousTag(LineTag tag) {
3116                         Line l;
3117
3118                         if (tag.previous != null) {
3119                                 return tag.previous;
3120                         }
3121
3122                         // Next line
3123                         if (tag.line.line_no == 1) {
3124                                 return null;
3125                         }
3126
3127                         l = GetLine(tag.line.line_no - 1);
3128                         if (l != null) {
3129                                 LineTag t;
3130
3131                                 t = l.tags;
3132                                 while (t.next != null) {
3133                                         t = t.next;
3134                                 }
3135                                 return t;
3136                         }
3137
3138                         return null;
3139                 }
3140
3141                 /// <summary>Retrieve the next tag; walks line boundaries</summary>
3142                 internal LineTag NextTag(LineTag tag) {
3143                         Line l;
3144
3145                         if (tag.next != null) {
3146                                 return tag.next;
3147                         }
3148
3149                         // Next line
3150                         l = GetLine(tag.line.line_no + 1);
3151                         if (l != null) {
3152                                 return l.tags;
3153                         }
3154
3155                         return null;
3156                 }
3157
3158                 internal Line ParagraphStart(Line line) {
3159                         while (line.ending == LineEnding.Wrap) {
3160                                 line = GetLine(line.line_no - 1);
3161                         }
3162                         return line;
3163                 }
3164
3165                 internal Line ParagraphEnd(Line line) {
3166                         Line    l;
3167
3168                         while (line.ending == LineEnding.Wrap) {
3169                                 l = GetLine(line.line_no + 1);
3170                                 if ((l == null) || (l.ending != LineEnding.Wrap)) {
3171                                         break;
3172                                 }
3173                                 line = l;
3174                         }
3175                         return line;
3176                 }
3177
3178                 /// <summary>Give it a pixel offset coordinate and it returns the Line covering that are (offset
3179                 /// is either X or Y depending on if we are multiline
3180                 /// </summary>
3181                 internal Line GetLineByPixel (int offset, bool exact)
3182                 {
3183                         Line    line = document;
3184                         Line    last = null;
3185
3186                         if (multiline) {
3187                                 while (line != sentinel) {
3188                                         last = line;
3189                                         if ((offset >= line.Y) && (offset < (line.Y+line.height))) {
3190                                                 return line;
3191                                         } else if (offset < line.Y) {
3192                                                 line = line.left;
3193                                         } else {
3194                                                 line = line.right;
3195                                         }
3196                                 }
3197                         } else {
3198                                 while (line != sentinel) {
3199                                         last = line;
3200                                         if ((offset >= line.X) && (offset < (line.X + line.Width)))
3201                                                 return line;
3202                                         else if (offset < line.X)
3203                                                 line = line.left;
3204                                         else
3205                                                 line = line.right;
3206                                 }
3207                         }
3208
3209                         if (exact) {
3210                                 return null;
3211                         }
3212                         return last;
3213                 }
3214
3215                 // Give it x/y pixel coordinates and it returns the Tag at that position; optionally the char position is returned in index
3216                 internal LineTag FindTag(int x, int y, out int index, bool exact) {
3217                         Line    line;
3218                         LineTag tag;
3219
3220                         line = GetLineByPixel(y, exact);
3221                         if (line == null) {
3222                                 index = 0;
3223                                 return null;
3224                         }
3225                         tag = line.tags;
3226
3227                         // Alignment adjustment
3228                         x += line.X;
3229
3230                         while (true) {
3231                                 if (x >= tag.X && x < (tag.X+tag.Width)) {
3232                                         int     end;
3233
3234                                         end = tag.start + tag.Length - 1;
3235
3236                                         for (int pos = tag.start; pos < end; pos++) {
3237                                                 if (x < line.widths[pos]) {
3238                                                         index = pos;
3239                                                         return LineTag.GetFinalTag (tag);
3240                                                 }
3241                                         }
3242                                         index=end;
3243                                         return LineTag.GetFinalTag (tag);
3244                                 }
3245                                 if (tag.next != null) {
3246                                         tag = tag.next;
3247                                 } else {
3248                                         if (exact) {
3249                                                 index = 0;
3250                                                 return null;
3251                                         }
3252
3253                                         index = line.text.Length;
3254                                         return LineTag.GetFinalTag (tag);
3255                                 }
3256                         }
3257                 }
3258
3259                 // Give it x/y pixel coordinates and it returns the Tag at that position; optionally the char position is returned in index
3260                 internal LineTag FindCursor(int x, int y, out int index) {
3261                         Line    line;
3262                         LineTag tag;
3263
3264                         line = GetLineByPixel(multiline ? y : x, false);
3265                         tag = line.tags;
3266
3267                         /// Special case going leftwards of the first tag
3268                         if (x < tag.X) {
3269                                 index = 0;
3270                                 return LineTag.GetFinalTag (tag);
3271                         }
3272
3273                         while (true) {
3274                                 if (x >= tag.X && x < (tag.X+tag.Width)) {
3275                                         int     end;
3276
3277                                         end = tag.TextEnd;
3278
3279                                         for (int pos = tag.start - 1; pos < end; pos++) {
3280                                                 // When clicking on a character, we position the cursor to whatever edge
3281                                                 // of the character the click was closer
3282                                                 if (x < (line.X + line.widths[pos] + ((line.widths[pos+1]-line.widths[pos])/2))) {
3283                                                         index = pos;
3284                                                         return LineTag.GetFinalTag (tag);
3285                                                 }
3286                                         }
3287                                         index=end;
3288                                         return LineTag.GetFinalTag (tag);
3289                                 }
3290                                 if (tag.next != null) {
3291                                         tag = tag.next;
3292                                 } else {
3293                                         index = line.TextLengthWithoutEnding ();
3294                                         return LineTag.GetFinalTag (tag);
3295                                 }
3296                         }
3297                 }
3298
3299                 /// <summary>Format area of document in specified font and color</summary>
3300                 /// <param name="start_pos">1-based start position on start_line</param>
3301                 /// <param name="end_pos">1-based end position on end_line </param>
3302                 internal void FormatText (Line start_line, int start_pos, Line end_line, int end_pos, Font font,
3303                                 Color color, Color back_color, FormatSpecified specified)
3304                 {
3305                         Line    l;
3306
3307                         // First, format the first line
3308                         if (start_line != end_line) {
3309                                 // First line
3310                                 LineTag.FormatText(start_line, start_pos, start_line.text.Length - start_pos + 1, font, color, back_color, specified);
3311
3312                                 // Format last line
3313                                 LineTag.FormatText(end_line, 1, end_pos, font, color, back_color, specified);
3314
3315                                 // Now all the lines inbetween
3316                                 for (int i = start_line.line_no + 1; i < end_line.line_no; i++) {
3317                                         l = GetLine(i);
3318                                         LineTag.FormatText(l, 1, l.text.Length, font, color, back_color, specified);
3319                                 }
3320                         } else {
3321                                 // Special case, single line
3322                                 LineTag.FormatText(start_line, start_pos, end_pos - start_pos, font, color, back_color, specified);
3323                         }
3324                 }
3325
3326                 internal void RecalculateAlignments ()
3327                 {
3328                         Line    line;
3329                         int     line_no;
3330
3331                         line_no = 1;
3332
3333
3334
3335                         while (line_no <= lines) {
3336                                 line = GetLine(line_no);
3337
3338                                 if (line != null) {
3339                                         switch (line.alignment) {
3340                                         case HorizontalAlignment.Left:
3341                                                 line.align_shift = 0;
3342                                                 break;
3343                                         case HorizontalAlignment.Center:
3344                                                 line.align_shift = (viewport_width - (int)line.widths[line.text.Length]) / 2;
3345                                                 break;
3346                                         case HorizontalAlignment.Right:
3347                                                 line.align_shift = viewport_width - (int)line.widths[line.text.Length] - right_margin;
3348                                                 break;
3349                                         }
3350                                 }
3351
3352                                 line_no++;
3353                         }
3354                         return;
3355                 }
3356
3357                 /// <summary>Calculate formatting for the whole document</summary>
3358                 internal bool RecalculateDocument(Graphics g) {
3359                         return RecalculateDocument(g, 1, this.lines, false);
3360                 }
3361
3362                 /// <summary>Calculate formatting starting at a certain line</summary>
3363                 internal bool RecalculateDocument(Graphics g, int start) {
3364                         return RecalculateDocument(g, start, this.lines, false);
3365                 }
3366
3367                 /// <summary>Calculate formatting within two given line numbers</summary>
3368                 internal bool RecalculateDocument(Graphics g, int start, int end) {
3369                         return RecalculateDocument(g, start, end, false);
3370                 }
3371
3372                 /// <summary>With optimize on, returns true if line heights changed</summary>
3373                 internal bool RecalculateDocument(Graphics g, int start, int end, bool optimize) {
3374                         Line    line;
3375                         int     line_no;
3376                         int     offset;
3377                         int     new_width;
3378                         bool    changed;
3379                         int     shift;
3380
3381                         if (recalc_suspended > 0) {
3382                                 recalc_pending = true;
3383                                 recalc_start = Math.Min (recalc_start, start);
3384                                 recalc_end = Math.Max (recalc_end, end);
3385                                 recalc_optimize = optimize;
3386                                 return false;
3387                         }
3388
3389                         // Fixup the positions, they can go kinda nuts
3390                         start = Math.Max (start, 1);
3391                         end = Math.Min (end, lines);
3392
3393                         offset = GetLine(start).offset;
3394                         line_no = start;
3395                         new_width = 0;
3396                         shift = this.lines;
3397                         if (!optimize) {
3398                                 changed = true;         // We always return true if we run non-optimized
3399                         } else {
3400                                 changed = false;
3401                         }
3402
3403                         while (line_no <= (end + this.lines - shift)) {
3404                                 line = GetLine(line_no++);
3405                                 line.offset = offset;
3406
3407                                 if (!calc_pass) {
3408                                         if (!optimize) {
3409                                                 line.RecalculateLine(g, this);
3410                                         } else {
3411                                                 if (line.recalc && line.RecalculateLine(g, this)) {
3412                                                         changed = true;
3413                                                         // If the height changed, all subsequent lines change
3414                                                         end = this.lines;
3415                                                         shift = this.lines;
3416                                                 }
3417                                         }
3418                                 } else {
3419                                         if (!optimize) {
3420                                                 line.RecalculatePasswordLine(g, this);
3421                                         } else {
3422                                                 if (line.recalc && line.RecalculatePasswordLine(g, this)) {
3423                                                         changed = true;
3424                                                         // If the height changed, all subsequent lines change
3425                                                         end = this.lines;
3426                                                         shift = this.lines;
3427                                                 }
3428                                         }
3429                                 }
3430
3431                                 if (line.widths[line.text.Length] > new_width) {
3432                                         new_width = (int)line.widths[line.text.Length];
3433                                 }
3434
3435                                 // Calculate alignment
3436                                 if (line.alignment != HorizontalAlignment.Left) {
3437                                         if (line.alignment == HorizontalAlignment.Center) {
3438                                                 line.align_shift = (viewport_width - (int)line.widths[line.text.Length]) / 2;
3439                                         } else {
3440                                                 line.align_shift = viewport_width - (int)line.widths[line.text.Length] - 1;
3441                                         }
3442                                 }
3443
3444                                 if (multiline)
3445                                         offset += line.height;
3446                                 else
3447                                         offset += (int) line.widths [line.text.Length];
3448
3449                                 if (line_no > lines) {
3450                                         break;
3451                                 }
3452                         }
3453
3454                         if (document_x != new_width) {
3455                                 document_x = new_width;
3456                                 if (WidthChanged != null) {
3457                                         WidthChanged(this, null);
3458                                 }
3459                         }
3460
3461                         RecalculateAlignments();
3462
3463                         line = GetLine(lines);
3464
3465                         if (document_y != line.Y + line.height) {
3466                                 document_y = line.Y + line.height;
3467                                 if (HeightChanged != null) {
3468                                         HeightChanged(this, null);
3469                                 }
3470                         }
3471                         UpdateCaret();
3472                         return changed;
3473                 }
3474
3475                 internal int Size() {
3476                         return lines;
3477                 }
3478
3479                 private void owner_HandleCreated(object sender, EventArgs e) {
3480                         RecalculateDocument(owner.CreateGraphicsInternal());
3481                         AlignCaret();
3482                 }
3483
3484                 private void owner_VisibleChanged(object sender, EventArgs e) {
3485                         if (owner.Visible) {
3486                                 RecalculateDocument(owner.CreateGraphicsInternal());
3487                         }
3488                 }
3489
3490                 internal static bool IsWordSeparator (char ch)
3491                 {
3492                         switch (ch) {
3493                         case ' ':
3494                         case '\t':
3495                         case '(':
3496                         case ')':
3497                         case '\r':
3498                         case '\n':
3499                                 return true;
3500                         default:
3501                                 return false;
3502                         }
3503                 }
3504
3505                 internal int FindWordSeparator(Line line, int pos, bool forward) {
3506                         int len;
3507
3508                         len = line.text.Length;
3509
3510                         if (forward) {
3511                                 for (int i = pos + 1; i < len; i++) {
3512                                         if (IsWordSeparator(line.Text[i])) {
3513                                                 return i + 1;
3514                                         }
3515                                 }
3516                                 return len;
3517                         } else {
3518                                 for (int i = pos - 1; i > 0; i--) {
3519                                         if (IsWordSeparator(line.Text[i - 1])) {
3520                                                 return i;
3521                                         }
3522                                 }
3523                                 return 0;
3524                         }
3525                 }
3526
3527                 /* Search document for text */
3528                 internal bool FindChars(char[] chars, Marker start, Marker end, out Marker result) {
3529                         Line    line;
3530                         int     line_no;
3531                         int     pos;
3532                         int     line_len;
3533
3534                         // Search for occurence of any char in the chars array
3535                         result = new Marker();
3536
3537                         line = start.line;
3538                         line_no = start.line.line_no;
3539                         pos = start.pos;
3540                         while (line_no <= end.line.line_no) {
3541                                 line_len = line.text.Length;
3542                                 while (pos < line_len) {
3543                                         for (int i = 0; i < chars.Length; i++) {
3544                                                 if (line.text[pos] == chars[i]) {
3545                                                         // Special case
3546                                                         if ((line.line_no == end.line.line_no) && (pos >= end.pos)) {
3547                                                                 return false;
3548                                                         }
3549
3550                                                         result.line = line;
3551                                                         result.pos = pos;
3552                                                         return true;
3553                                                 }
3554                                         }
3555                                         pos++;
3556                                 }
3557
3558                                 pos = 0;
3559                                 line_no++;
3560                                 line = GetLine(line_no);
3561                         }
3562
3563                         return false;
3564                 }
3565
3566                 // This version does not build one big string for searching, instead it handles
3567                 // line-boundaries, which is faster and less memory intensive
3568                 // FIXME - Depending on culture stuff we might have to create a big string and use culturespecific
3569                 // search stuff and change it to accept and return positions instead of Markers (which would match
3570                 // RichTextBox behaviour better but would be inconsistent with the rest of TextControl)
3571                 internal bool Find(string search, Marker start, Marker end, out Marker result, RichTextBoxFinds options) {
3572                         Marker  last;
3573                         string  search_string;
3574                         Line    line;
3575                         int     line_no;
3576                         int     pos;
3577                         int     line_len;
3578                         int     current;
3579                         bool    word;
3580                         bool    word_option;
3581                         bool    ignore_case;
3582                         bool    reverse;
3583                         char    c;
3584
3585                         result = new Marker();
3586                         word_option = ((options & RichTextBoxFinds.WholeWord) != 0);
3587                         ignore_case = ((options & RichTextBoxFinds.MatchCase) == 0);
3588                         reverse = ((options & RichTextBoxFinds.Reverse) != 0);
3589
3590                         line = start.line;
3591                         line_no = start.line.line_no;
3592                         pos = start.pos;
3593                         current = 0;
3594
3595                         // Prep our search string, lowercasing it if we do case-independent matching
3596                         if (ignore_case) {
3597                                 StringBuilder   sb;
3598                                 sb = new StringBuilder(search);
3599                                 for (int i = 0; i < sb.Length; i++) {
3600                                         sb[i] = Char.ToLower(sb[i]);
3601                                 }
3602                                 search_string = sb.ToString();
3603                         } else {
3604                                 search_string = search;
3605                         }
3606
3607                         // We need to check if the character before our start position is a wordbreak
3608                         if (word_option) {
3609                                 if (line_no == 1) {
3610                                         if ((pos == 0) || (IsWordSeparator(line.text[pos - 1]))) {
3611                                                 word = true;
3612                                         } else {
3613                                                 word = false;
3614                                         }
3615                                 } else {
3616                                         if (pos > 0) {
3617                                                 if (IsWordSeparator(line.text[pos - 1])) {
3618                                                         word = true;
3619                                                 } else {
3620                                                         word = false;
3621                                                 }
3622                                         } else {
3623                                                 // Need to check the end of the previous line
3624                                                 Line    prev_line;
3625
3626                                                 prev_line = GetLine(line_no - 1);
3627                                                 if (prev_line.ending == LineEnding.Wrap) {
3628                                                         if (IsWordSeparator(prev_line.text[prev_line.text.Length - 1])) {
3629                                                                 word = true;
3630                                                         } else {
3631                                                                 word = false;
3632                                                         }
3633                                                 } else {
3634                                                         word = true;
3635                                                 }
3636                                         }
3637                                 }
3638                         } else {
3639                                 word = false;
3640                         }
3641
3642                         // To avoid duplication of this loop with reverse logic, we search
3643                         // through the document, remembering the last match and when returning
3644                         // report that last remembered match
3645
3646                         last = new Marker();
3647                         last.height = -1;       // Abused - we use it to track change
3648
3649                         while (line_no <= end.line.line_no) {
3650                                 if (line_no != end.line.line_no) {
3651                                         line_len = line.text.Length;
3652                                 } else {
3653                                         line_len = end.pos;
3654                                 }
3655
3656                                 while (pos < line_len) {
3657
3658                                         if (word_option && (current == search_string.Length)) {
3659                                                 if (IsWordSeparator(line.text[pos])) {
3660                                                         if (!reverse) {
3661                                                                 goto FindFound;
3662                                                         } else {
3663                                                                 last = result;
3664                                                                 current = 0;
3665                                                         }
3666                                                 } else {
3667                                                         current = 0;
3668                                                 }
3669                                         }
3670
3671                                         if (ignore_case) {
3672                                                 c = Char.ToLower(line.text[pos]);
3673                                         } else {
3674                                                 c = line.text[pos];
3675                                         }
3676
3677                                         if (c == search_string[current]) {
3678
3679                                                 if (current == 0) {
3680                                                         result.line = line;
3681                                                         result.pos = pos;
3682                                                 }
3683                                                 if (!word_option || (word_option && (word || (current > 0)))) {
3684                                                         current++;
3685                                                 }
3686
3687                                                 if (!word_option && (current == search_string.Length)) {
3688                                                         if (!reverse) {
3689                                                                 goto FindFound;
3690                                                         } else {
3691                                                                 last = result;
3692                                                                 current = 0;
3693                                                         }
3694                                                 }
3695                                         } else {
3696                                                 current = 0;
3697                                         }
3698                                         pos++;
3699
3700                                         if (!word_option) {
3701                                                 continue;
3702                                         }
3703
3704                                         if (IsWordSeparator(c)) {
3705                                                 word = true;
3706                                         } else {
3707                                                 word = false;
3708                                         }
3709                                 }
3710
3711                                 if (word_option) {
3712                                         // Mark that we just saw a word boundary
3713                                         if (line.ending != LineEnding.Wrap || line.line_no == lines - 1) {
3714                                                 word = true;
3715                                         }
3716
3717                                         if (current == search_string.Length) {
3718                                                 if (word) {
3719                                                         if (!reverse) {
3720                                                                 goto FindFound;
3721                                                         } else {
3722                                                                 last = result;
3723                                                                 current = 0;
3724                                                         }
3725                                                 } else {
3726                                                         current = 0;
3727                                                 }
3728                                         }
3729                                 }
3730
3731                                 pos = 0;
3732                                 line_no++;
3733                                 line = GetLine(line_no);
3734                         }
3735
3736                         if (reverse) {
3737                                 if (last.height != -1) {
3738                                         result = last;
3739                                         return true;
3740                                 }
3741                         }
3742
3743                         return false;
3744
3745                         FindFound:
3746                         if (!reverse) {
3747 //                              if ((line.line_no == end.line.line_no) && (pos >= end.pos)) {
3748 //                                      return false;
3749 //                              }
3750                                 return true;
3751                         }
3752
3753                         result = last;
3754                         return true;
3755
3756                 }
3757
3758                 /* Marker stuff */
3759                 internal void GetMarker(out Marker mark, bool start) {
3760                         mark = new Marker();
3761
3762                         if (start) {
3763                                 mark.line = GetLine(1);
3764                                 mark.tag = mark.line.tags;
3765                                 mark.pos = 0;
3766                         } else {
3767                                 mark.line = GetLine(lines);
3768                                 mark.tag = mark.line.tags;
3769                                 while (mark.tag.next != null) {
3770                                         mark.tag = mark.tag.next;
3771                                 }
3772                                 mark.pos = mark.line.text.Length;
3773                         }
3774                 }
3775                 #endregion      // Internal Methods
3776
3777                 #region Events
3778                 internal event EventHandler CaretMoved;
3779                 internal event EventHandler WidthChanged;
3780                 internal event EventHandler HeightChanged;
3781                 internal event EventHandler LengthChanged;
3782                 #endregion      // Events
3783
3784                 #region Administrative
3785                 public IEnumerator GetEnumerator() {
3786                         // FIXME
3787                         return null;
3788                 }
3789
3790                 public override bool Equals(object obj) {
3791                         if (obj == null) {
3792                                 return false;
3793                         }
3794
3795                         if (!(obj is Document)) {
3796                                 return false;
3797                         }
3798
3799                         if (obj == this) {
3800                                 return true;
3801                         }
3802
3803                         if (ToString().Equals(((Document)obj).ToString())) {
3804                                 return true;
3805                         }
3806
3807                         return false;
3808                 }
3809
3810                 public override int GetHashCode() {
3811                         return document_id;
3812                 }
3813
3814                 public override string ToString() {
3815                         return "document " + this.document_id;
3816                 }
3817                 #endregion      // Administrative
3818         }
3819
3820         internal class PictureTag : LineTag {
3821
3822                 internal RTF.Picture picture;
3823
3824                 internal PictureTag (Line line, int start, RTF.Picture picture) : base (line, start)
3825                 {
3826                         this.picture = picture;
3827                 }
3828
3829                 public override bool IsTextTag {
3830                         get { return false; }
3831                 }
3832
3833                 internal override SizeF SizeOfPosition (Graphics dc, int pos)
3834                 {
3835                         return picture.Size;
3836                 }
3837
3838                 internal override int MaxHeight ()
3839                 {
3840                         return (int) (picture.Height + 0.5F);
3841                 }
3842
3843                 internal override void Draw (Graphics dc, Color color, float xoff, float y, int start, int end)
3844                 {
3845                         picture.DrawImage (dc, xoff + line.widths [start], y, false);
3846                 }
3847
3848                 internal override void Draw (Graphics dc, Color color, float xoff, float y, int start, int end, string text)
3849                 {
3850                         picture.DrawImage (dc, xoff + + line.widths [start], y, false);
3851                 }
3852
3853                 public override string Text ()
3854                 {
3855                         return "I";
3856                 }
3857         }
3858
3859         internal class UndoManager {
3860
3861                 internal enum ActionType {
3862
3863                         Typing,
3864
3865                         // This is basically just cut & paste
3866                         InsertString,
3867                         DeleteString,
3868
3869                         UserActionBegin,
3870                         UserActionEnd
3871                 }
3872
3873                 internal class Action {
3874                         internal ActionType     type;
3875                         internal int            line_no;
3876                         internal int            pos;
3877                         internal object         data;
3878                 }
3879
3880                 #region Local Variables
3881                 private Document        document;
3882                 private Stack           undo_actions;
3883                 private Stack           redo_actions;
3884
3885                 //private int           caret_line;
3886                 //private int           caret_pos;
3887
3888                 // When performing an action, we lock the queue, so that the action can't be undone
3889                 private bool locked;
3890                 #endregion      // Local Variables
3891
3892                 #region Constructors
3893                 internal UndoManager (Document document)
3894                 {
3895                         this.document = document;
3896                         undo_actions = new Stack (50);
3897                         redo_actions = new Stack (50);
3898                 }
3899                 #endregion      // Constructors
3900
3901                 #region Properties
3902                 internal bool CanUndo {
3903                         get { return undo_actions.Count > 0; }
3904                 }
3905
3906                 internal bool CanRedo {
3907                         get { return redo_actions.Count > 0; }
3908                 }
3909
3910                 internal string UndoActionName {
3911                         get {
3912                                 foreach (Action action in undo_actions) {
3913                                         if (action.type == ActionType.UserActionBegin)
3914                                                 return (string) action.data;
3915                                         if (action.type == ActionType.Typing)
3916                                                 return Locale.GetText ("Typing");
3917                                 }
3918                                 return String.Empty;
3919                         }
3920                 }
3921
3922                 internal string RedoActionName {
3923                         get {
3924                                 foreach (Action action in redo_actions) {
3925                                         if (action.type == ActionType.UserActionBegin)
3926                                                 return (string) action.data;
3927                                         if (action.type == ActionType.Typing)
3928                                                 return Locale.GetText ("Typing");
3929                                 }
3930                                 return String.Empty;
3931                         }
3932                 }
3933                 #endregion      // Properties
3934
3935                 #region Internal Methods
3936                 internal void Clear ()
3937                 {
3938                         undo_actions.Clear();
3939                         redo_actions.Clear();
3940                 }
3941
3942                 internal void Undo ()
3943                 {
3944                         Action action;
3945                         bool user_action_finished = false;
3946
3947                         if (undo_actions.Count == 0)
3948                                 return;
3949
3950                         // Nuke the redo queue
3951                         redo_actions.Clear ();
3952
3953                         locked = true;
3954                         do {
3955                                 Line start;
3956                                 action = (Action) undo_actions.Pop ();
3957
3958                                 // Put onto redo stack
3959                                 redo_actions.Push(action);
3960
3961                                 // Do the thing
3962                                 switch(action.type) {
3963
3964                                 case ActionType.UserActionBegin:
3965                                         user_action_finished = true;
3966                                         break;
3967
3968                                 case ActionType.UserActionEnd:
3969                                         // noop
3970                                         break;
3971
3972                                 case ActionType.InsertString:
3973                                         start = document.GetLine (action.line_no);
3974                                         document.SuspendUpdate ();
3975                                         document.DeleteMultiline (start, action.pos, ((string) action.data).Length + 1);
3976                                         document.PositionCaret (start, action.pos);
3977                                         document.SetSelectionToCaret (true);
3978                                         document.ResumeUpdate (true);
3979                                         break;
3980
3981                                 case ActionType.Typing:
3982                                         start = document.GetLine (action.line_no);
3983                                         document.SuspendUpdate ();
3984                                         document.DeleteMultiline (start, action.pos, ((StringBuilder) action.data).Length);
3985                                         document.PositionCaret (start, action.pos);
3986                                         document.SetSelectionToCaret (true);
3987                                         document.ResumeUpdate (true);
3988
3989                                         // This is an open ended operation, so only a single typing operation can be undone at once
3990                                         user_action_finished = true;
3991                                         break;
3992
3993                                 case ActionType.DeleteString:
3994                                         start = document.GetLine (action.line_no);
3995                                         document.SuspendUpdate ();
3996                                         Insert (start, action.pos, (Line) action.data, true);
3997                                         document.ResumeUpdate (true);
3998                                         break;
3999                                 }
4000                         } while (!user_action_finished && undo_actions.Count > 0);
4001
4002                         locked = false;
4003                 }
4004
4005                 internal void Redo ()
4006                 {
4007                         Action action;
4008                         bool user_action_finished = false;
4009
4010                         if (redo_actions.Count == 0)
4011                                 return;
4012
4013                         // You can't undo anything after redoing
4014                         undo_actions.Clear ();
4015
4016                         locked = true;
4017                         do {
4018                                 Line start;
4019                                 int start_index;
4020
4021                                 action = (Action) redo_actions.Pop ();
4022
4023                                 switch (action.type) {
4024
4025                                 case ActionType.UserActionBegin:
4026                                         //  Noop
4027                                         break;
4028
4029                                 case ActionType.UserActionEnd:
4030                                         user_action_finished = true;
4031                                         break;
4032
4033                                 case ActionType.InsertString:
4034                                         start = document.GetLine (action.line_no);
4035                                         document.SuspendUpdate ();
4036                                         start_index = document.LineTagToCharIndex (start, action.pos);
4037                                         document.InsertString (start, action.pos, (string) action.data);
4038                                         document.CharIndexToLineTag (start_index + ((string) action.data).Length,
4039                                                         out document.caret.line, out document.caret.tag,
4040                                                         out document.caret.pos);
4041                                         document.UpdateCaret ();
4042                                         document.SetSelectionToCaret (true);
4043                                         document.ResumeUpdate (true);
4044                                         break;
4045
4046                                 case ActionType.Typing:
4047                                         start = document.GetLine (action.line_no);
4048                                         document.SuspendUpdate ();
4049                                         start_index = document.LineTagToCharIndex (start, action.pos);
4050                                         document.InsertString (start, action.pos, ((StringBuilder) action.data).ToString ());
4051                                         document.CharIndexToLineTag (start_index + ((StringBuilder) action.data).Length,
4052                                                         out document.caret.line, out document.caret.tag,
4053                                                         out document.caret.pos);
4054                                         document.UpdateCaret ();
4055                                         document.SetSelectionToCaret (true);
4056                                         document.ResumeUpdate (true);
4057
4058                                         // This is an open ended operation, so only a single typing operation can be undone at once
4059                                         user_action_finished = true;
4060                                         break;
4061
4062                                 case ActionType.DeleteString:
4063                                         start = document.GetLine (action.line_no);
4064                                         document.SuspendUpdate ();
4065                                         document.DeleteMultiline (start, action.pos, ((Line) action.data).text.Length);
4066                                         document.PositionCaret (start, action.pos);
4067                                         document.SetSelectionToCaret (true);
4068                                         document.ResumeUpdate (true);
4069
4070                                         break;
4071                                 }
4072                         } while (!user_action_finished && redo_actions.Count > 0);
4073
4074                         locked = false;
4075                 }
4076                 #endregion      // Internal Methods
4077
4078                 #region Private Methods
4079
4080                 public void BeginUserAction (string name)
4081                 {
4082                         if (locked)
4083                                 return;
4084
4085                         Action ua = new Action ();
4086                         ua.type = ActionType.UserActionBegin;
4087                         ua.data = name;
4088
4089                         undo_actions.Push (ua);
4090                 }
4091
4092                 public void EndUserAction ()
4093                 {
4094                         if (locked)
4095                                 return;
4096
4097                         Action ua = new Action ();
4098                         ua.type = ActionType.UserActionEnd;
4099
4100                         undo_actions.Push (ua);
4101                 }
4102
4103                 // start_pos, end_pos = 1 based
4104                 public void RecordDeleteString (Line start_line, int start_pos, Line end_line, int end_pos)
4105                 {
4106                         if (locked)
4107                                 return;
4108
4109                         Action  a = new Action ();
4110
4111                         // We cant simply store the string, because then formatting would be lost
4112                         a.type = ActionType.DeleteString;
4113                         a.line_no = start_line.line_no;
4114                         a.pos = start_pos;
4115                         a.data = Duplicate (start_line, start_pos, end_line, end_pos);
4116
4117                         undo_actions.Push(a);
4118                 }
4119
4120                 public void RecordInsertString (Line line, int pos, string str)
4121                 {
4122                         if (locked || str.Length == 0)
4123                                 return;
4124
4125                         Action a = new Action ();
4126
4127                         a.type = ActionType.InsertString;
4128                         a.data = str;
4129                         a.line_no = line.line_no;
4130                         a.pos = pos;
4131
4132                         undo_actions.Push (a);
4133                 }
4134
4135                 public void RecordTyping (Line line, int pos, char ch)
4136                 {
4137                         if (locked)
4138                                 return;
4139
4140                         Action a = null;
4141
4142                         if (undo_actions.Count > 0)
4143                                 a = (Action) undo_actions.Peek ();
4144
4145                         if (a == null || a.type != ActionType.Typing) {
4146                                 a = new Action ();
4147                                 a.type = ActionType.Typing;
4148                                 a.data = new StringBuilder ();
4149                                 a.line_no = line.line_no;
4150                                 a.pos = pos;
4151
4152                                 undo_actions.Push (a);
4153                         }
4154
4155                         StringBuilder data = (StringBuilder) a.data;
4156                         data.Append (ch);
4157                 }
4158
4159                 // start_pos = 1-based
4160                 // end_pos = 1-based
4161                 public Line Duplicate(Line start_line, int start_pos, Line end_line, int end_pos)
4162                 {
4163                         Line    ret;
4164                         Line    line;
4165                         Line    current;
4166                         LineTag tag;
4167                         LineTag current_tag;
4168                         int     start;
4169                         int     end;
4170                         int     tag_start;
4171
4172                         line = new Line (start_line.document, start_line.ending);
4173                         ret = line;
4174
4175                         for (int i = start_line.line_no; i <= end_line.line_no; i++) {
4176                                 current = document.GetLine(i);
4177
4178                                 if (start_line.line_no == i) {
4179                                         start = start_pos;
4180                                 } else {
4181                                         start = 0;
4182                                 }
4183
4184                                 if (end_line.line_no == i) {
4185                                         end = end_pos;
4186                                 } else {
4187                                         end = current.text.Length;
4188                                 }
4189
4190                                 if (end_pos == 0)
4191                                         continue;
4192
4193                                 // Text for the tag
4194                                 line.text = new StringBuilder (current.text.ToString (start, end - start));
4195
4196                                 // Copy tags from start to start+length onto new line
4197                                 current_tag = current.FindTag (start);
4198                                 while ((current_tag != null) && (current_tag.start <= end)) {
4199                                         if ((current_tag.start <= start) && (start < (current_tag.start + current_tag.Length))) {
4200                                                 // start tag is within this tag
4201                                                 tag_start = start;
4202                                         } else {
4203                                                 tag_start = current_tag.start;
4204                                         }
4205
4206                                         tag = new LineTag(line, tag_start - start + 1);
4207                                         tag.CopyFormattingFrom (current_tag);
4208
4209                                         current_tag = current_tag.next;
4210
4211                                         // Add the new tag to the line
4212                                         if (line.tags == null) {
4213                                                 line.tags = tag;
4214                                         } else {
4215                                                 LineTag tail;
4216                                                 tail = line.tags;
4217
4218                                                 while (tail.next != null) {
4219                                                         tail = tail.next;
4220                                                 }
4221                                                 tail.next = tag;
4222                                                 tag.previous = tail;
4223                                         }
4224                                 }
4225
4226                                 if ((i + 1) <= end_line.line_no) {
4227                                         line.ending = current.ending;
4228
4229                                         // Chain them (we use right/left as next/previous)
4230                                         line.right = new Line (start_line.document, start_line.ending);
4231                                         line.right.left = line;
4232                                         line = line.right;
4233                                 }
4234                         }
4235
4236                         return ret;
4237                 }
4238
4239                 // Insert multi-line text at the given position; use formatting at insertion point for inserted text
4240                 internal void Insert(Line line, int pos, Line insert, bool select)
4241                 {
4242                         Line    current;
4243                         LineTag tag;
4244                         int     offset;
4245                         int     lines;
4246                         Line    first;
4247
4248                         // Handle special case first
4249                         if (insert.right == null) {
4250
4251                                 // Single line insert
4252                                 document.Split(line, pos);
4253
4254                                 if (insert.tags == null) {
4255                                         return; // Blank line
4256                                 }
4257
4258                                 //Insert our tags at the end
4259                                 tag = line.tags;
4260
4261                                 while (tag.next != null) {
4262                                         tag = tag.next;
4263                                 }
4264
4265                                 offset = tag.start + tag.Length - 1;
4266
4267                                 tag.next = insert.tags;
4268                                 line.text.Insert(offset, insert.text.ToString());
4269
4270                                 // Adjust start locations
4271                                 tag = tag.next;
4272                                 while (tag != null) {
4273                                         tag.start += offset;
4274                                         tag.line = line;
4275                                         tag = tag.next;
4276                                 }
4277                                 // Put it back together
4278                                 document.Combine(line.line_no, line.line_no + 1);
4279
4280                                 if (select) {
4281                                         document.SetSelectionStart (line, pos, false);
4282                                         document.SetSelectionEnd (line, pos + insert.text.Length, false);
4283                                 }
4284
4285                                 document.UpdateView(line, pos);
4286                                 return;
4287                         }
4288
4289                         first = line;
4290                         lines = 1;
4291                         current = insert;
4292
4293                         while (current != null) {
4294
4295                                 if (current == insert) {
4296                                         // Inserting the first line we split the line (and make space)
4297                                         document.Split(line.line_no, pos);
4298                                         //Insert our tags at the end of the line
4299                                         tag = line.tags;
4300
4301
4302                                         if (tag != null && tag.Length != 0) {
4303                                                 while (tag.next != null) {
4304                                                         tag = tag.next;
4305                                                 }
4306                                                 offset = tag.start + tag.Length - 1;
4307                                                 tag.next = current.tags;
4308                                                 tag.next.previous = tag;
4309
4310                                                 tag = tag.next;
4311
4312                                         } else {
4313                                                 offset = 0;
4314                                                 line.tags = current.tags;
4315                                                 line.tags.previous = null;
4316                                                 tag = line.tags;
4317                                         }
4318
4319                                         line.ending = current.ending;
4320                                 } else {
4321                                         document.Split(line.line_no, 0);
4322                                         offset = 0;
4323                                         line.tags = current.tags;
4324                                         line.tags.previous = null;
4325                                         line.ending = current.ending;
4326                                         tag = line.tags;
4327                                 }
4328
4329                                 // Adjust start locations and line pointers
4330                                 while (tag != null) {
4331                                         tag.start += offset - 1;
4332                                         tag.line = line;
4333                                         tag = tag.next;
4334                                 }
4335
4336                                 line.text.Insert(offset, current.text.ToString());
4337                                 line.Grow(line.text.Length);
4338
4339                                 line.recalc = true;
4340                                 line = document.GetLine(line.line_no + 1);
4341
4342                                 // FIXME? Test undo of line-boundaries
4343                                 if ((current.right == null) && (current.tags.Length != 0)) {
4344                                         document.Combine(line.line_no - 1, line.line_no);
4345                                 }
4346                                 current = current.right;
4347                                 lines++;
4348
4349                         }
4350
4351                         // Recalculate our document
4352                         document.UpdateView(first, lines, pos);
4353                         return;
4354                 }
4355                 #endregion      // Private Methods
4356         }
4357 }