1 // Copyright 2003 Adam Megacz, see the COPYING file for licensing [GPL]
6 import org.xwt.translators.*;
9 * The in-memory representation of a PNG or GIF image. It is
10 * read-only. It is usually passed to PixelBuffer.drawPicture()
12 * Implementations of the Platform class should return objects
13 * supporting this interface from the createPicture() method. These
14 * implementations may choose to implement caching strategies (for
15 * example, using a Pixmap on X11).
17 public class Picture {
19 public Picture() { this.res = null; }
20 public Picture(Res r) { this.res = r; }
21 private static Cache cache = new Cache(100); ///< Picture, keyed by the Res that loaded them
23 public Res res = null; ///< the resource we were loaded from
24 public int width = -1; ///< the width of the image
25 public int height = -1; ///< the height of the image
26 public int[] data = null; ///< argb samples
27 public boolean isLoaded = false; ///< true iff the image is fully loaded
29 /** turns a resource into a Picture.Source and passes it to the callback */
30 public static Picture load(final Res r, final Scheduler.Task callback) {
31 Picture ret = (Picture)cache.get(r);
32 if (ret == null) cache.put(r, ret = Platform.createPicture(r));
33 if (!ret.isLoaded && callback != null)
34 new java.lang.Thread() { public void run() {
36 PushbackInputStream pbis = new PushbackInputStream(r.getInputStream());
38 int firstByte = pbis.read();
39 if (firstByte == -1) throw new JSExn("empty stream reading image");
40 pbis.unread(firstByte);
41 if ((firstByte & 0xff) == 'G') GIF.load(pbis, p);
42 else if ((firstByte & 0xff) == 137) PNG.load(pbis, p);
43 else if ((firstByte & 0xff) == 0xff) Platform.decodeJPEG(pbis, p);
44 else throw new JSExn("couldn't figure out image type from first byte");
45 Scheduler.add(callback);
46 } catch (Exception e) {
47 Log.log(this, "exception while loading image");