mcs/class/Managed.Windows.Forms/System.Windows.Forms.Layout/FlowLayout.cs

   1 //
   2 // FlowLayout.cs
   3 //
   4 // Permission is hereby granted, free of charge, to any person obtaining
   5 // a copy of this software and associated documentation files (the
   6 // "Software"), to deal in the Software without restriction, including
   7 // without limitation the rights to use, copy, modify, merge, publish,
   8 // distribute, sublicense, and/or sell copies of the Software, and to
   9 // permit persons to whom the Software is furnished to do so, subject to
  10 // the following conditions:
  11 //
  12 // The above copyright notice and this permission notice shall be
  13 // included in all copies or substantial portions of the Software.
  14 //
  15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  18 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  19 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  20 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  21 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22 //
  23 // Copyright (c) 2006 Jonathan Pobst
  24 //
  25 // Authors:
  26 //      Jonathan Pobst (monkey@jpobst.com)
  27 //
  28
  29 #if NET_2_0
  30 using System;
  31 using System.Collections.Generic;
  32 using System.Drawing;
  33
  34 namespace System.Windows.Forms.Layout
  35 {
  36         class FlowLayout : LayoutEngine
  37         {
  38                 public FlowLayout ()
  39                 {
  40                 }
  41
  42                 public override void InitLayout (object child, BoundsSpecified specified)
  43                 {
  44                         base.InitLayout (child, specified);
  45                 }
  46
  47                 public override bool Layout (object container, LayoutEventArgs args)
  48                 {
  49                         Control parent = container as Control;
  50                         FlowLayoutSettings settings = (parent as FlowLayoutPanel).LayoutSettings;
  51
  52                         // Nothing to layout, exit method
  53                         if (parent.Controls.Count == 0) return false;
  54
  55                         // Use DisplayRectangle so that parent.Padding is honored.
  56                         Rectangle parentDisplayRectangle = parent.DisplayRectangle;
  57                         Point currentLocation;
  58
  59                         // Set our starting point based on flow direction
  60                         switch (settings.FlowDirection) {
  61                                 case FlowDirection.BottomUp:
  62                                         currentLocation = new Point (parentDisplayRectangle.Left, parentDisplayRectangle.Bottom);
  63                                         break;
  64                                 case FlowDirection.LeftToRight:
  65                                 case FlowDirection.TopDown:
  66                                 default:
  67                                         currentLocation = parentDisplayRectangle.Location;
  68                                         break;
  69                                 case FlowDirection.RightToLeft:
  70                                         currentLocation = new Point (parentDisplayRectangle.Right, parentDisplayRectangle.Top);
  71                                         break;
  72                         }
  73
  74                         bool forceFlowBreak = false;
  75
  76                         List<Control> rowControls = new List<Control> ();
  77
  78                         foreach (Control c in parent.Controls) {
  79                                 // Only apply layout to visible controls.
  80                                 if (!c.Visible) { continue; }
  81
  82                                 // Resize any AutoSize controls to their preferred size
  83                                 if (c.AutoSize == true)
  84                                         c.Size = c.GetPreferredSize (c.Size);
  85
  86                                 switch (settings.FlowDirection) {
  87                                         case FlowDirection.BottomUp:
  88                                                 // Decide if it's time to start a new column
  89                                                 // - Our settings must be WrapContents, and we ran out of room or the previous control's FlowBreak == true
  90                                                 if (settings.WrapContents)
  91                                                         if ((currentLocation.Y) < (c.Height + c.Margin.Top + c.Margin.Bottom) || forceFlowBreak) {
  92
  93                                                                 currentLocation.X = FinishColumn (rowControls);
  94                                                                 currentLocation.Y = parentDisplayRectangle.Bottom;
  95
  96                                                                 forceFlowBreak = false;
  97                                                                 rowControls.Clear ();
  98                                                         }
  99
 100                                                 // Offset the right margin and set the control to our point
 101                                                 currentLocation.Offset (0, c.Margin.Bottom * -1);
 102                                                 c.Location = new Point (currentLocation.X + c.Margin.Left, currentLocation.Y - c.Height);
 103
 104                                                 // Update our location pointer
 105                                                 currentLocation.Y -= (c.Height + c.Margin.Top);
 106                                                 break;
 107                                         case FlowDirection.LeftToRight:
 108                                         default:
 109                                                 // Decide if it's time to start a new row
 110                                                 // - Our settings must be WrapContents, and we ran out of room or the previous control's FlowBreak == true
 111                                                 if (settings.WrapContents)
 112                                                         if ((parentDisplayRectangle.Width - currentLocation.X) < (c.Width + c.Margin.Left + c.Margin.Right) || forceFlowBreak) {
 113
 114                                                                 currentLocation.Y = FinishRow (rowControls);
 115                                                                 currentLocation.X = parentDisplayRectangle.Left;
 116
 117                                                                 forceFlowBreak = false;
 118                                                                 rowControls.Clear ();
 119                                                         }
 120
 121                                                 // Offset the left margin and set the control to our point
 122                                                 currentLocation.Offset (c.Margin.Left, 0);
 123                                                 c.Location = new Point (currentLocation.X, currentLocation.Y + c.Margin.Top);
 124
 125                                                 // Update our location pointer
 126                                                 currentLocation.X += c.Width + c.Margin.Right;
 127                                                 break;
 128                                         case FlowDirection.RightToLeft:
 129                                                 // Decide if it's time to start a new row
 130                                                 // - Our settings must be WrapContents, and we ran out of room or the previous control's FlowBreak == true
 131                                                 if (settings.WrapContents)
 132                                                         if ((currentLocation.X) < (c.Width + c.Margin.Left + c.Margin.Right) || forceFlowBreak) {
 133
 134                                                                 currentLocation.Y = FinishRow (rowControls);
 135                                                                 currentLocation.X = parentDisplayRectangle.Right;
 136
 137                                                                 forceFlowBreak = false;
 138                                                                 rowControls.Clear ();
 139                                                         }
 140
 141                                                 // Offset the right margin and set the control to our point
 142                                                 currentLocation.Offset (c.Margin.Right * -1, 0);
 143                                                 c.Location = new Point (currentLocation.X - c.Width, currentLocation.Y + c.Margin.Top);
 144
 145                                                 // Update our location pointer
 146                                                 currentLocation.X -= (c.Width + c.Margin.Left);
 147                                                 break;
 148                                         case FlowDirection.TopDown:
 149                                                 // Decide if it's time to start a new column
 150                                                 // - Our settings must be WrapContents, and we ran out of room or the previous control's FlowBreak == true
 151                                                 if (settings.WrapContents)
 152                                                         if ((parentDisplayRectangle.Height - currentLocation.Y) < (c.Height + c.Margin.Top + c.Margin.Bottom) || forceFlowBreak) {
 153
 154                                                                 currentLocation.X = FinishColumn (rowControls);
 155                                                                 currentLocation.Y = parentDisplayRectangle.Top;
 156
 157                                                                 forceFlowBreak = false;
 158                                                                 rowControls.Clear ();
 159                                                         }
 160
 161                                                 // Offset the top margin and set the control to our point
 162                                                 currentLocation.Offset (0, c.Margin.Top);
 163                                                 c.Location = new Point (currentLocation.X + c.Margin.Left, currentLocation.Y);
 164
 165                                                 // Update our location pointer
 166                                                 currentLocation.Y += c.Height + c.Margin.Bottom;
 167                                                 break;
 168                                 }
 169                                 // Add it to our list of things to adjust the second dimension of
 170                                 rowControls.Add (c);
 171
 172                                 // If user set a flowbreak on this control, it will be the last one in this row/column
 173                                 if (settings.GetFlowBreak (c))
 174                                         forceFlowBreak = true;
 175                         }
 176
 177                         // Set the control heights/widths for the last row/column
 178                         if (settings.FlowDirection == FlowDirection.LeftToRight || settings.FlowDirection == FlowDirection.RightToLeft)
 179                                 FinishRow (rowControls);
 180                         else
 181                                 FinishColumn (rowControls);
 182
 183                         return false;
 184                 }
 185
 186                 // Calculate the heights of the controls, returns the y coordinate of the greatest height it uses
 187                 private int FinishRow (List<Control> row)
 188                 {
 189                         // Nothing to do
 190                         if (row.Count == 0) return 0;
 191
 192                         int rowTop = int.MaxValue;
 193                         int rowBottom = 0;
 194                         bool allDockFill = true;
 195                         bool noAuto = true;
 196
 197                         // Special semantics if all controls are Dock.Fill/Anchor:Top,Bottom or AutoSize = true
 198                         foreach (Control c in row) {
 199                                 if (c.Dock != DockStyle.Fill && !((c.Anchor & AnchorStyles.Top) == AnchorStyles.Top && (c.Anchor & AnchorStyles.Bottom) == AnchorStyles.Bottom))
 200                                         allDockFill = false;
 201                                 if (c.AutoSize == true)
 202                                         noAuto = false;
 203                         }
 204
 205                         // Find the tallest control with a concrete height
 206                         foreach (Control c in row) {
 207                                 if (c.Bottom + c.Margin.Bottom > rowBottom && (c.Dock != DockStyle.Fill) && ((c.Anchor & AnchorStyles.Top) != AnchorStyles.Top || (c.Anchor & AnchorStyles.Bottom) != AnchorStyles.Bottom || c.AutoSize == true))
 208                                         rowBottom = c.Bottom + c.Margin.Bottom;
 209                                 if (c.Top - c.Margin.Top < rowTop)
 210                                         rowTop = c.Top - c.Margin.Top;
 211                         }
 212
 213                         // Find the tallest control that is AutoSize = true
 214                         if (rowBottom == 0)
 215                                 foreach (Control c in row)
 216                                         if (c.Bottom + c.Margin.Bottom > rowBottom && (c.Dock != DockStyle.Fill && c.AutoSize == true))
 217                                                 rowBottom = c.Bottom + c.Margin.Bottom;
 218
 219                         // Find the tallest control that is Dock = Fill
 220                         if (rowBottom == 0)
 221                                 foreach (Control c in row)
 222                                         if (c.Bottom + c.Margin.Bottom > rowBottom && (c.Dock == DockStyle.Fill))
 223                                                 rowBottom = c.Bottom + c.Margin.Bottom;
 224
 225                         // Set the new heights for each control
 226                         foreach (Control c in row)
 227                                 if (allDockFill && noAuto)
 228                                         c.Height = 0;
 229                                 else if (c.Dock == DockStyle.Fill || ((c.Anchor & AnchorStyles.Top) == AnchorStyles.Top) && ((c.Anchor & AnchorStyles.Bottom) == AnchorStyles.Bottom))
 230                                         c.Height = rowBottom - c.Top - c.Margin.Bottom;
 231                                 else if (c.Dock == DockStyle.Bottom || ((c.Anchor & AnchorStyles.Bottom) == AnchorStyles.Bottom))
 232                                         c.Top = rowBottom - c.Margin.Bottom - c.Height;
 233                                 else if (c.Dock == DockStyle.Top || ((c.Anchor & AnchorStyles.Top) == AnchorStyles.Top))
 234                                         continue;
 235                                 else
 236                                         c.Top = ((rowBottom - rowTop) / 2) - (c.Height / 2) + (int)Math.Floor (((c.Margin.Top - c.Margin.Bottom) / 2.0)) + rowTop;
 237
 238                         // Return bottom y of this row used
 239                         if (rowBottom == 0)
 240                                 return rowTop;
 241
 242                         return rowBottom;
 243                 }
 244
 245                 // Calculate the widths of the controls, returns the x coordinate of the greatest width it uses
 246                 private int FinishColumn (List<Control> col)
 247                 {
 248                         // Nothing to do
 249                         if (col.Count == 0) return 0;
 250
 251                         int rowLeft = int.MaxValue;
 252                         int rowRight = 0;
 253                         bool allDockFill = true;
 254                         bool noAuto = true;
 255
 256                         // Special semantics if all controls are Dock.Fill/Anchor:Left,Right or AutoSize = true
 257                         foreach (Control c in col) {
 258                                 if (c.Dock != DockStyle.Fill && !((c.Anchor & AnchorStyles.Left) == AnchorStyles.Left && (c.Anchor & AnchorStyles.Right) == AnchorStyles.Right))
 259                                         allDockFill = false;
 260                                 if (c.AutoSize == true)
 261                                         noAuto = false;
 262                         }
 263
 264                         // Find the widest control with a concrete width
 265                         foreach (Control c in col) {
 266                                 if (c.Right + c.Margin.Right > rowRight && (c.Dock != DockStyle.Fill) && ((c.Anchor & AnchorStyles.Left) != AnchorStyles.Left || (c.Anchor & AnchorStyles.Right) != AnchorStyles.Right || c.AutoSize == true))
 267                                         rowRight = c.Right + c.Margin.Right;
 268                                 if (c.Left - c.Margin.Left < rowLeft)
 269                                         rowLeft = c.Left - c.Margin.Left;
 270                         }
 271
 272                         // Find the widest control that is AutoSize = true
 273                         if (rowRight == 0)
 274                                 foreach (Control c in col)
 275                                         if (c.Right + c.Margin.Right > rowRight && (c.Dock != DockStyle.Fill && c.AutoSize == true))
 276                                                 rowRight = c.Right + c.Margin.Right;
 277
 278                         // Find the widest control that is Dock = Fill
 279                         if (rowRight == 0)
 280                                 foreach (Control c in col)
 281                                         if (c.Right + c.Margin.Right > rowRight && (c.Dock == DockStyle.Fill))
 282                                                 rowRight = c.Right + c.Margin.Right;
 283
 284                         // Set the new widths for each control
 285                         foreach (Control c in col)
 286                                 if (allDockFill && noAuto)
 287                                         c.Width = 0;
 288                                 else if (c.Dock == DockStyle.Fill || ((c.Anchor & AnchorStyles.Left) == AnchorStyles.Left) && ((c.Anchor & AnchorStyles.Right) == AnchorStyles.Right))
 289                                         c.Width = rowRight - c.Left - c.Margin.Right;
 290                                 else if (c.Dock == DockStyle.Right || ((c.Anchor & AnchorStyles.Right) == AnchorStyles.Right))
 291                                         c.Left = rowRight - c.Margin.Right - c.Width;
 292                                 else if (c.Dock == DockStyle.Left || ((c.Anchor & AnchorStyles.Left) == AnchorStyles.Left))
 293                                         continue;
 294                                 else
 295                                         c.Left = ((rowRight - rowLeft) / 2) - (c.Width / 2) + (int)Math.Floor (((c.Margin.Left - c.Margin.Right) / 2.0)) + rowLeft;
 296
 297                         // Return rightmost x of this row used
 298                         if (rowRight == 0)
 299                                 return rowLeft;
 300
 301                         return rowRight;
 302                 }
 303         }
 304 }
 305 #endif