mcs/class/System.Web/System.Web.UI.WebControls/DataGridColumn.cs

   1 //
   2 // System.Web.UI.WebControls.DataGridColumn.cs
   3 //
   4 // Authors:
   5 //   Gaurav Vaish (gvaish@iitk.ac.in)
   6 //   Andreas Nahr (ClassDevelopment@A-SoftTech.com)
   7 //
   8 // (C) Gaurav Vaish (2002)
   9 // (C) 2003 Andreas Nahr
  10 //
  11
  12 using System;
  13 using System.Web;
  14 using System.Web.UI;
  15 using System.ComponentModel;
  16
  17 namespace System.Web.UI.WebControls
  18 {
  19         [TypeConverter(typeof(ExpandableObjectConverter))]
  20         public abstract class DataGridColumn : IStateManager
  21         {
  22                 private StateBag viewState;
  23                 private bool     marked;
  24                 private TableItemStyle footerStyle;
  25                 private TableItemStyle headerStyle;
  26                 private TableItemStyle itemStyle;
  27
  28                 private DataGrid owner;
  29                 private bool     designMode;
  30
  31                 public DataGridColumn()
  32                 {
  33                         viewState = new StateBag();
  34                 }
  35
  36                 internal TableItemStyle FooterStyleInternal
  37                 {
  38                         get
  39                         {
  40                                 return footerStyle;
  41                         }
  42                 }
  43
  44                 internal TableItemStyle HeaderStyleInternal
  45                 {
  46                         get
  47                         {
  48                                 return headerStyle;
  49                         }
  50                 }
  51
  52                 internal TableItemStyle ItemStyleInternal
  53                 {
  54                         get
  55                         {
  56                                 return itemStyle;
  57                         }
  58                 }
  59
  60                 [DefaultValue (null), WebCategory ("Misc")]
  61                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Content)]
  62                 [PersistenceMode (PersistenceMode.InnerProperty)]
  63                 [WebSysDescription ("The style applied to the footer of this column.")]
  64                 public virtual TableItemStyle FooterStyle
  65                 {
  66                         get
  67                         {
  68                                 if(footerStyle == null)
  69                                 {
  70                                         footerStyle = new TableItemStyle();
  71                                         if(IsTrackingViewState)
  72                                         {
  73                                                 footerStyle.TrackViewState();
  74                                         }
  75                                 }
  76                                 return footerStyle;
  77                         }
  78                 }
  79
  80                 [DefaultValue (null), WebCategory ("Misc")]
  81                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Content)]
  82                 [PersistenceMode (PersistenceMode.InnerProperty)]
  83                 [WebSysDescription ("The style applied to the header of this column.")]
  84                 public virtual TableItemStyle HeaderStyle
  85                 {
  86                         get
  87                         {
  88                                 if(headerStyle == null)
  89                                 {
  90                                         headerStyle= new TableItemStyle();
  91                                         if(IsTrackingViewState)
  92                                         {
  93                                                 headerStyle.TrackViewState();
  94                                         }
  95                                 }
  96                                 return headerStyle;
  97                         }
  98                 }
  99
 100                 [DefaultValue (null), WebCategory ("Misc")]
 101                 [DesignerSerializationVisibility (DesignerSerializationVisibility.Content)]
 102                 [PersistenceMode (PersistenceMode.InnerProperty)]
 103                 [WebSysDescription ("The style applied to the rows of this column.")]
 104                 public virtual TableItemStyle ItemStyle
 105                 {
 106                         get
 107                         {
 108                                 if(itemStyle == null)
 109                                 {
 110                                         itemStyle = new TableItemStyle();
 111                                         if(IsTrackingViewState)
 112                                         {
 113                                                 itemStyle.TrackViewState();
 114                                         }
 115                                 }
 116                                 return itemStyle;
 117                         }
 118                 }
 119
 120                 [DefaultValue (""), WebCategory ("Misc")]
 121                 [WebSysDescription ("The text within the footer of this column.")]
 122                 public virtual string FooterText
 123                 {
 124                         get
 125                         {
 126                                 object o = ViewState["FooterText"];
 127                                 if(o != null)
 128                                 {
 129                                         return (string)o;
 130                                 }
 131                                 return String.Empty;
 132                         }
 133                         set
 134                         {
 135                                 ViewState["FooterText"] = value;
 136                                 OnColumnChanged();
 137                         }
 138                 }
 139
 140                 [DefaultValue (""), WebCategory ("Misc")]
 141                 [WebSysDescription ("The URL to an image that is displayed in the header of this column.")]
 142                 public virtual string HeaderImageUrl
 143                 {
 144                         get
 145                         {
 146                                 object o = ViewState["HeaderImageUrl"];
 147                                 if(o != null)
 148                                 {
 149                                         return (string)o;
 150                                 }
 151                                 return String.Empty;
 152                         }
 153                         set
 154                         {
 155                                 ViewState["HeaderImageUrl"] = value;
 156                                 OnColumnChanged();
 157                         }
 158                 }
 159
 160                 [DefaultValue (""), WebCategory ("Misc")]
 161                 [WebSysDescription ("The text within the header of this column.")]
 162                 public virtual string HeaderText
 163                 {
 164                         get
 165                         {
 166                                 object o = ViewState["HeaderText"];
 167                                 if(o != null)
 168                                 {
 169                                         return (string)o;
 170                                 }
 171                                 return String.Empty;
 172                         }
 173                         set
 174                         {
 175                                 ViewState["HeaderText"] = value;
 176                                 OnColumnChanged();
 177                         }
 178                 }
 179
 180                 [DefaultValue (""), WebCategory ("Misc")]
 181                 [WebSysDescription ("An expression that determines how the colum should be sorted.")]
 182                 public virtual string SortExpression
 183                 {
 184                         get
 185                         {
 186                                 object o = ViewState["SortExpression"];
 187                                 if(o != null)
 188                                 {
 189                                         return (string)o;
 190                                 }
 191                                 return String.Empty;
 192                         }
 193                         set
 194                         {
 195                                 ViewState["SortExpression"] = value;
 196                                 OnColumnChanged();
 197                         }
 198                 }
 199
 200                 [DefaultValue (true), WebCategory ("Misc")]
 201                 [WebSysDescription ("The visibility of this column.")]
 202                 public bool Visible
 203                 {
 204                         get
 205                         {
 206                                 object o = ViewState["Visible"];
 207                                 if(o != null)
 208                                 {
 209                                         return (bool)o;
 210                                 }
 211                                 return true;
 212                         }
 213                         set
 214                         {
 215                                 ViewState["Visible"] = value;
 216                                 OnColumnChanged();
 217                         }
 218                 }
 219
 220                 public virtual void Initialize()
 221                 {
 222                         if(owner != null && owner.Site != null)
 223                         {
 224                                 designMode = owner.Site.DesignMode;
 225                         }
 226                 }
 227
 228                 public virtual void InitializeCell(TableCell cell, int columnIndex, ListItemType itemType)
 229                 {
 230                         switch(itemType)
 231                         {
 232                                 case ListItemType.Header : InitializeCellHeader(cell, columnIndex);
 233                                                            break;
 234                                 case ListItemType.Footer : InitializeCellFooter(cell, columnIndex);
 235                                                            break;
 236                                 default                  : if (ItemStyleInternal != null)
 237                                                                 cell.ApplyStyle (ItemStyleInternal);
 238                                                            return;
 239                         }
 240                 }
 241
 242                 private void InitializeCellHeader(TableCell cell, int columnIndex)
 243                 {
 244                         WebControl ctrl = null;
 245                         bool       sort = true;
 246                         string     sortExpr = "";
 247                         ImageButton headButton;
 248                         Image       headImage;
 249                         LinkButtonInternal link;
 250
 251                         if(owner != null)
 252                         {
 253                                 sort = owner.AllowSorting;
 254                         }
 255                         if(sort)
 256                         {
 257                                 sortExpr = SortExpression;
 258                                 if(sortExpr.Length == 0)
 259                                 {
 260                                         sort = false;
 261                                 }
 262                         }
 263                         if(HeaderImageUrl.Length > 0)
 264                         {
 265                                 if(sort)
 266                                 {
 267                                         headButton = new ImageButton();
 268                                         headButton.ImageUrl = HeaderImageUrl;
 269                                         headButton.CommandName = "Sort";
 270                                         headButton.CommandArgument = sortExpr;
 271                                         headButton.CausesValidation = false;
 272                                         ctrl = headButton;
 273                                 } else
 274                                 {
 275                                         headImage = new Image();
 276                                         headImage.ImageUrl = HeaderImageUrl;
 277                                         ctrl = headImage;
 278                                 }
 279                         } else
 280                         {
 281                                 if(sort)
 282                                 {
 283                                         link = new LinkButtonInternal();
 284                                         link.Text = HeaderText;
 285                                         link.CommandName = "Sort";
 286                                         link.CommandArgument = sortExpr;
 287                                         link.CausesValidation = false;
 288                                         ctrl = link;
 289                                 } else
 290                                 {
 291                                         if(HeaderText.Length > 0)
 292                                         {
 293                                                 cell.Text = HeaderText;
 294                                         } else
 295                                         {
 296                                                 cell.Text = "&nbsp;";
 297                                         }
 298                                 }
 299                         }
 300                         if(ctrl != null)
 301                         {
 302                                 cell.Controls.Add(ctrl);
 303                         }
 304                         if (HeaderStyleInternal != null)
 305                                 cell.ApplyStyle (HeaderStyleInternal);
 306                 }
 307
 308                 private void InitializeCellFooter(TableCell cell, int columnIndex)
 309                 {
 310                         cell.Text = (FooterText.Length > 0 ? FooterText : "&nbsp;");
 311                         if (FooterStyleInternal != null)
 312                                 cell.ApplyStyle (FooterStyleInternal);
 313                 }
 314
 315                 public override string ToString()
 316                 {
 317                         return String.Empty;
 318                 }
 319
 320                 protected bool DesignMode
 321                 {
 322                         get
 323                         {
 324                                 return designMode;
 325                         }
 326                 }
 327
 328                 protected DataGrid Owner
 329                 {
 330                         get
 331                         {
 332                                 return owner;
 333                         }
 334                 }
 335
 336                 protected StateBag ViewState
 337                 {
 338                         get
 339                         {
 340                                 return viewState;
 341                         }
 342                 }
 343
 344                 /// <summary>
 345                 /// Undocumented
 346                 /// </summary>
 347                 protected virtual void OnColumnChanged()
 348                 {
 349                         if(owner != null)
 350                         {
 351                                 owner.OnColumnsChanged();
 352                         }
 353                 }
 354
 355                 internal void SetOwner (DataGrid datagrid)
 356                 {
 357                         owner = datagrid;
 358                 }
 359
 360                 protected virtual object SaveViewState()
 361                 {
 362                         object[] states = new object[4];
 363                         states[0] = ViewState.SaveViewState();
 364                         states[1] = (footerStyle == null ? null : footerStyle.SaveViewState());
 365                         states[2] = (headerStyle == null ? null : headerStyle.SaveViewState());
 366                         states[3] = (itemStyle == null ? null : itemStyle.SaveViewState());
 367
 368                         for (int i = 0; i < states.Length; i++) {
 369                                 if (states [i] != null)
 370                                         return states;
 371                         }
 372                         return null;
 373                 }
 374
 375                 protected virtual void LoadViewState(object savedState)
 376                 {
 377                         if (savedState == null)
 378                                 return;
 379
 380                         object[] states = (object[]) savedState;
 381                         ViewState.LoadViewState (states [0]);
 382                         FooterStyle.LoadViewState (states [1]);
 383                         HeaderStyle.LoadViewState (states [2]);
 384                         ItemStyle.LoadViewState (states [3]);
 385                 }
 386
 387                 protected virtual void TrackViewState()
 388                 {
 389                         marked = true;
 390                         ViewState.TrackViewState();
 391                         if(footerStyle != null)
 392                         {
 393                                 footerStyle.TrackViewState();
 394                         }
 395                         if(headerStyle != null)
 396                         {
 397                                 headerStyle.TrackViewState();
 398                         }
 399                         if(itemStyle != null)
 400                         {
 401                                 itemStyle.TrackViewState();
 402                         }
 403                 }
 404
 405                 protected bool IsTrackingViewState
 406                 {
 407                         get
 408                         {
 409                                 return marked;
 410                         }
 411                 }
 412
 413                 void IStateManager.LoadViewState(object savedState)
 414                 {
 415                         LoadViewState(savedState);
 416                 }
 417
 418                 object IStateManager.SaveViewState()
 419                 {
 420                         return SaveViewState();
 421                 }
 422
 423                 void IStateManager.TrackViewState()
 424                 {
 425                         TrackViewState();
 426                 }
 427
 428                 bool IStateManager.IsTrackingViewState
 429                 {
 430                         get
 431                         {
 432                                 return IsTrackingViewState;
 433                         }
 434                 }
 435         }
 436 }