mcs/class/Managed.Windows.Forms/System.Windows.Forms/HandleData.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 Novell, Inc.
  21 //
  22 // Authors:
  23 //      Jackson Harper (jackson@ximian.com)
  24 //
  25 //
  26
  27
  28 using System;
  29 using System.Drawing;
  30 using System.Collections;
  31
  32 namespace System.Windows.Forms {
  33
  34         internal class HandleData : IDisposable {
  35
  36                 private Queue           message_queue;
  37                 private Rectangle       invalid = Rectangle.Empty;
  38                 private Object          dc;
  39                 private bool            has_expose;
  40                 private bool            is_visible;
  41
  42                 #region Constructors and destructors
  43                 public HandleData ()
  44                 {
  45                         is_visible = true;
  46                 }
  47
  48                 public void Dispose () {
  49                         DeviceContext = null;
  50                 }
  51                 #endregion
  52
  53                 #region Paint area handling
  54                 public Object DeviceContext {
  55                         get { return dc; }
  56                         set {
  57                                 if (value is Graphics) {
  58                                         if (dc != null) {
  59                                                 ((Graphics)dc).Dispose ();
  60                                         }
  61                                 }
  62                                 dc = value;
  63                         }
  64                 }
  65
  66                 public bool HasExpose {
  67                         get {
  68                                 return has_expose;
  69                         }
  70                         set {
  71                                 has_expose = value;
  72                         }
  73                 }
  74
  75                 public bool IsVisible {
  76                         get {
  77                                 return is_visible;
  78                         }
  79                         set {
  80                                 is_visible = value;
  81                         }
  82                 }
  83
  84                 public Rectangle InvalidArea {
  85                         get {
  86                                 return invalid;
  87                         }
  88                 }
  89
  90                 public void ScrollInvalidArea (int x, int y) {
  91                         if (invalid == Rectangle.Empty) {
  92                                 return;
  93                         }
  94
  95                         invalid.X += x;
  96                         invalid.Y += y;
  97
  98                         if (invalid.X < 0) {
  99                                 invalid.Width += invalid.X;
 100                                 invalid.X =0;
 101                         }
 102
 103                         if (invalid.Y < 0) {
 104                                 invalid.Height += invalid.Y;
 105                                 invalid.Y =0;
 106                         }
 107                 }
 108
 109                 public void AddToInvalidArea (int x, int y, int width, int height)
 110                 {
 111                         if (invalid == Rectangle.Empty) {
 112                                 invalid = new Rectangle (x, y, width, height);
 113                                 return;
 114                         }
 115                         invalid = Rectangle.Union (invalid, new Rectangle (x, y, width, height));
 116                 }
 117
 118                 public void AddToInvalidArea (Rectangle r)
 119                 {
 120                         if (invalid == Rectangle.Empty) {
 121                                 invalid = r;
 122                                 return;
 123                         }
 124                         invalid = Rectangle.Union (invalid, r);
 125                 }
 126
 127                 public void ClearInvalidArea ()
 128                 {
 129                         invalid = Rectangle.Empty;
 130                         has_expose = false;
 131                 }
 132                 #endregion      // Paint area methods
 133
 134                 #region Message storage and retrieval
 135                 public bool MessageWaiting {
 136                         get {
 137                                 if ((message_queue == null) || (message_queue.Count == 0)) {
 138                                         return false;
 139                                 }
 140                                 return true;
 141                         }
 142                 }
 143
 144                 public bool GetMessage(ref MSG msg) {
 145                         MSG     message;
 146
 147                         if ((message_queue == null) || (message_queue.Count == 0)) {
 148                                 return false;
 149                         }
 150
 151                         message = (MSG)message_queue.Dequeue();
 152                         msg = message;
 153
 154                         return true;
 155                 }
 156
 157                 public bool StoreMessage(ref MSG msg) {
 158                         MSG message = new MSG();
 159
 160                         if (message_queue == null) {
 161                                 message_queue = new Queue();
 162                         }
 163
 164                         message = msg;
 165                         message_queue.Enqueue(message);
 166
 167                         return true;
 168                 }
 169                 #endregion      // Message storage and retrieval
 170         }
 171 }
 172