2004/01/19 00:16:54
[org.ibex.core.git] / src / org / xwt / Picture.java
index 89db921..44565d5 100644 (file)
@@ -1,20 +1,66 @@
-// Copyright 2002 Adam Megacz, see the COPYING file for licensing [GPL]
+// Copyright 2004 Adam Megacz, see the COPYING file for licensing [GPL]
 package org.xwt;
+import java.io.*;
+import org.xwt.js.*;
+import org.xwt.util.*;
+import org.xwt.translators.*;
 
 /** 
- *    <p>
  *    The in-memory representation of a PNG or GIF image. It is
- *    read-only. It is usually passed to DoubleBuffer.drawPicture()
- *    </p>
+ *    read-only. It is usually passed to PixelBuffer.drawPicture()
  *
- *    <p>
  *    Implementations of the Platform class should return objects
  *    supporting this interface from the createPicture() method. These
  *    implementations may choose to implement caching strategies (for
  *    example, using a Pixmap on X11).
- *    </p>
  */
-public abstract class Picture {
-    public abstract int getHeight();
-    public abstract int getWidth();
+public class Picture {
+
+    public Picture() { this.stream = null; }
+    public Picture(JS r) { this.stream = r; }
+    private static Cache cache = new Cache(100);   ///< Picture, keyed by the Stream that loaded them
+
+    public JS stream = null;                       ///< the stream we were loaded from
+    public int width = -1;                         ///< the width of the image
+    public int height = -1;                        ///< the height of the image
+    public int[] data = null;                      ///< argb samples
+    public boolean isLoaded = false;               ///< true iff the image is fully loaded
+
+    /** invoked when an image is fully loaded; subclasses can use this to initialize platform-specific constructs */
+    protected void loaded() { isLoaded = true; }
+
+    /** turns a stream into a Picture.Source and passes it to the callback */
+    public static Picture load(final JS stream, final Scheduler.Task callback) {
+        Picture ret = (Picture)cache.get(stream);
+        if (ret == null) cache.put(stream, ret = Platform.createPicture(stream));
+        final Picture p = ret;
+        if (!ret.isLoaded && callback != null) {
+            final XWT.Blessing b = XWT.Blessing.getBlessing(stream);
+            new java.lang.Thread() { public void run() {
+                InputStream in = null;
+                try {
+                    in = b == null ? Stream.getInputStream(stream) : b.getImage();
+                } catch (IOException e) { Log.error(Picture.class, stream);
+                } catch (JSExn e) { Log.error(Picture.class, stream);
+                }
+                if (in == null) { Log.warn(Picture.class, "couldn't load image for stream " + stream); return; }
+                try {
+                    PushbackInputStream pbis = new PushbackInputStream(in);
+                    int firstByte = pbis.read();
+                    if (firstByte == -1) throw new JSExn("empty stream reading image");
+                    pbis.unread(firstByte);
+                    if ((firstByte & 0xff) == 'G') GIF.load(pbis, p);
+                    else if ((firstByte & 0xff) == 137)  PNG.load(pbis, p);
+                    else if ((firstByte & 0xff) == 0xff) Platform.decodeJPEG(pbis, p);
+                    else throw new JSExn("couldn't figure out image type from first byte");
+                    p.loaded();
+                    Scheduler.add(callback);
+                } catch (Exception e) {
+                    Log.info(this, "exception while loading image");
+                    Log.info(this, e);
+                }
+            } }.start();
+        }
+        return ret;
+    }
 }