class/System.Drawing/System.Drawing/ImageAnimator.cs

   1 //
   2 // System.Drawing.ImageAnimator.cs
   3 //
   4 // Authors:
   5 //      Dennis Hayes (dennish@Raytek.com)
   6 //      Sanjay Gupta (gsanjay@novell.com)
   7 //      Sebastien Pouliot  <sebastien@ximian.com>
   8 //
   9 // (C) 2002 Ximian, Inc
  10 // Copyright (C) 2004,2006-2007 Novell, Inc (http://www.novell.com)
  11 //
  12 // Permission is hereby granted, free of charge, to any person obtaining
  13 // a copy of this software and associated documentation files (the
  14 // "Software"), to deal in the Software without restriction, including
  15 // without limitation the rights to use, copy, modify, merge, publish,
  16 // distribute, sublicense, and/or sell copies of the Software, and to
  17 // permit persons to whom the Software is furnished to do so, subject to
  18 // the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be
  21 // included in all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  24 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  25 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  26 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  27 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  28 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  29 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  30 //
  31
  32 using System.Collections;
  33 using System.Drawing.Imaging;
  34 using System.Threading;
  35
  36 namespace System.Drawing {
  37
  38         class AnimateEventArgs : EventArgs {
  39
  40                 private int frameCount;
  41                 private int activeFrame;
  42                 private Thread thread;
  43
  44                 public AnimateEventArgs (Image image)
  45                 {
  46                         frameCount = image.GetFrameCount (FrameDimension.Time);
  47                 }
  48
  49                 public Thread RunThread {
  50                         get { return thread; }
  51                         set { thread = value; }
  52                 }
  53
  54                 public int GetNextFrame ()
  55                 {
  56                         if (activeFrame < frameCount - 1)
  57                                 activeFrame++;
  58                         else
  59                                 activeFrame = 0;
  60
  61                         return activeFrame;
  62                 }
  63         }
  64
  65         public sealed class ImageAnimator {
  66
  67                 static Hashtable ht = Hashtable.Synchronized (new Hashtable ());
  68
  69                 private ImageAnimator ()
  70                 {
  71                 }
  72
  73                 public static void Animate (Image image, EventHandler onFrameChangedHandler)
  74                 {
  75                         // must be non-null and contain animation time frames
  76                         if (!CanAnimate (image))
  77                                 return;
  78
  79                         // is animation already in progress ?
  80                         if (ht.ContainsKey (image))
  81                                 return;
  82
  83                         PropertyItem item = image.GetPropertyItem (0x5100); // FrameDelay in libgdiplus
  84                         byte[] value = item.Value;
  85                         int[] delay = new int [(value.Length >> 2)];
  86                         for (int i=0, n=0; i < value.Length; i += 4, n++) {
  87                                 int d = BitConverter.ToInt32 (value, i) * 10;
  88                                 // follow worse case (Opera) see http://news.deviantart.com/article/27613/
  89                                 delay [n] = d < 100 ? 100 : d;
  90                         }
  91
  92                         AnimateEventArgs aea = new AnimateEventArgs (image);
  93                         WorkerThread wt = new WorkerThread (onFrameChangedHandler, aea, delay);
  94                         Thread thread = new Thread (new ThreadStart (wt.LoopHandler));
  95                         thread.IsBackground = true;
  96                         aea.RunThread = thread;
  97                         ht.Add (image, aea);
  98                         thread.Start ();
  99                 }
 100
 101                 public static bool CanAnimate (Image image)
 102                 {
 103                         if (image == null)
 104                                 return false;
 105
 106                         int n = image.FrameDimensionsList.Length;
 107                         if (n < 1)
 108                                 return false;
 109
 110                         for (int i = 0; i < n; i++) {
 111                                 if (image.FrameDimensionsList [i].Equals (FrameDimension.Time.Guid)) {
 112                                         return (image.GetFrameCount (FrameDimension.Time) > 1);
 113                                 }
 114                         }
 115                         return false;
 116                 }
 117
 118                 public static void StopAnimate (Image image, EventHandler onFrameChangedHandler)
 119                 {
 120                         if (image == null)
 121                                 return;
 122
 123                         if (ht.ContainsKey (image)) {
 124                                 AnimateEventArgs evtArgs = (AnimateEventArgs) ht [image];
 125                                 evtArgs.RunThread.Abort ();
 126                                 ht.Remove (image);
 127                         }
 128                 }
 129
 130                 public static void UpdateFrames ()
 131                 {
 132                         foreach (Image image in ht.Keys)
 133                                 UpdateImageFrame (image);
 134                 }
 135
 136
 137                 public static void UpdateFrames (Image image)
 138                 {
 139                         if (image == null)
 140                                 return;
 141
 142                         if (ht.ContainsKey (image))
 143                                 UpdateImageFrame (image);
 144                 }
 145
 146                 // this method avoid checks that aren't requied for UpdateFrames()
 147                 private static void UpdateImageFrame (Image image)
 148                 {
 149                         AnimateEventArgs aea = (AnimateEventArgs) ht [image];
 150                         image.SelectActiveFrame (FrameDimension.Time, aea.GetNextFrame ());
 151                 }
 152         }
 153
 154         class WorkerThread {
 155
 156                 private EventHandler frameChangeHandler;
 157                 private AnimateEventArgs animateEventArgs;
 158                 private int[] delay;
 159
 160                 public WorkerThread (EventHandler frmChgHandler, AnimateEventArgs aniEvtArgs, int[] delay)
 161                 {
 162                         frameChangeHandler = frmChgHandler;
 163                         animateEventArgs = aniEvtArgs;
 164                         this.delay = delay;
 165                 }
 166
 167                 public void LoopHandler ()
 168                 {
 169                         try {
 170                                 int n = 0;
 171                                 while (true) {
 172                                         Thread.Sleep (delay [n++]);
 173                                         frameChangeHandler (null, animateEventArgs);
 174                                         if (n == delay.Length)
 175                                                 n = 0;
 176                                 }
 177                         }
 178                         catch (ThreadAbortException) {
 179                                 Thread.ResetAbort (); // we're going to finish anyway
 180                         }
 181                 }
 182         }
 183 }