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
  41                 #region Constructors and destructors
  42                 public HandleData ()
  43                 {
  44                 }
  45
  46                 public void Dispose () {
  47                         DeviceContext = null;
  48                 }
  49                 #endregion
  50
  51                 #region Paint area handling
  52                 public Object DeviceContext {
  53                         get { return dc; }
  54                         set {
  55                                 if (value is Graphics) {
  56                                         if (dc != null) {
  57                                                 ((Graphics)dc).Dispose ();
  58                                         }
  59                                 }
  60                                 dc = value;
  61                         }
  62                 }
  63
  64                 public bool HasExpose {
  65                         get {
  66                                 return has_expose;
  67                         }
  68                         set {
  69                                 has_expose = value;
  70                         }
  71                 }
  72
  73                 public Rectangle InvalidArea {
  74                         get {
  75                                 return invalid;
  76                         }
  77                 }
  78                 public void AddToInvalidArea (int x, int y, int width, int height)
  79                 {
  80                         if (invalid == Rectangle.Empty) {
  81                                 invalid = new Rectangle (x, y, width, height);
  82                                 return;
  83                         }
  84                         invalid = Rectangle.Union (invalid, new Rectangle (x, y, width, height));
  85                 }
  86
  87                 public void AddToInvalidArea (Rectangle r)
  88                 {
  89                         if (invalid == Rectangle.Empty) {
  90                                 invalid = r;
  91                                 return;
  92                         }
  93                         invalid = Rectangle.Union (invalid, r);
  94                 }
  95
  96                 public void ClearInvalidArea ()
  97                 {
  98                         invalid = Rectangle.Empty;
  99                         has_expose = false;
 100                 }
 101                 #endregion      // Paint area methods
 102
 103                 #region Message storage and retrieval
 104                 public bool MessageWaiting {
 105                         get {
 106                                 if ((message_queue == null) || (message_queue.Count == 0)) {
 107                                         return false;
 108                                 }
 109                                 return true;
 110                         }
 111                 }
 112
 113                 public bool GetMessage(ref MSG msg) {
 114                         MSG     message;
 115
 116                         if ((message_queue == null) || (message_queue.Count == 0)) {
 117                                 return false;
 118                         }
 119
 120                         message = (MSG)message_queue.Dequeue();
 121                         msg = message;
 122
 123                         return true;
 124                 }
 125
 126                 public bool StoreMessage(ref MSG msg) {
 127                         MSG message = new MSG();
 128
 129                         if (message_queue == null) {
 130                                 message_queue = new Queue();
 131                         }
 132
 133                         message = msg;
 134                         message_queue.Enqueue(message);
 135
 136                         return true;
 137                 }
 138                 #endregion      // Message storage and retrieval
 139         }
 140 }
 141