java: Add progress meter for rendering of page contents.

For slow-rendering PDFs this will pop up a progress meter dialog
that allows the user get feed back on progress or abort the rendering.
An example of this is torture-test.pdf with its huge amount of paths.

platform/java/example/Viewer.java

@@ -126,6 +126,7 @@ public class Viewer extends Frame implements WindowListener, ActionListener, Ite
 	protected List outlineList;
 
 	protected OCRProgressmeter OCRmeter;
+	protected RenderProgressmeter renderMeter;
 
 	protected int number = 0;
 
@@ -578,10 +579,17 @@ protected void render() {
 		ctm.f -= atOrigin.y0;
 		Rect bounds = new Rect(bbox).transform(ctm);
 
-		doc.renderPage(ctm, bounds, icc, antialias, invert, tint, tintBlack, tintWhite,
+		Cookie cookie = new Cookie();
+
+		renderMeter = new RenderProgressmeter(this, "Rendering...", cookie, 250);
+		renderMeter.setLocationRelativeTo(this);
+		pageCanvas.requestFocusInWindow();
+
+		doc.renderPage(ctm, bounds, icc, antialias, invert, tint, tintBlack, tintWhite, cookie,
 			new ViewerCore.OnException() {
 				public void run(Throwable t) {
-					exception(t);
+					if (!renderMeter.cancelled)
+						exception(t);
 				}
 			}
 		);
@@ -1804,6 +1812,73 @@ public boolean progress(int page, int percent) {
 		}
 	}
 
+	class RenderProgressmeter extends Progressmeter {
+		Cookie cookie;
+
+		public RenderProgressmeter(Frame parent, String title, Cookie cookie, final int update) {
+			super(parent, title, false, "Progress: 100%");
+			this.cookie = cookie;
+
+			(new Thread() {
+				public void run() {
+					try {
+						int slept = 0;
+						while (!progress(slept))
+						{
+							sleep(update);
+							slept += update;
+						}
+					} catch (InterruptedException e) {
+					}
+				}
+			}).start();
+		}
+
+		public void cancel() {
+			super.cancel();
+			cookie.abort();
+		}
+
+		public boolean progress(int slept) {
+			int progress = cookie.getProgress();
+			int max = cookie.getProgressMax();
+
+			if (max <= 0 && progress < 100)
+				max = 100;
+			else if (max <= 0 && progress > 100)
+			{
+				int v = progress;
+				max = 10;
+				while (v > 10)
+				{
+					v /= 10;
+					max *= 10;
+				}
+			}
+
+			if (progress >= max)
+				done = true;
+
+			int percent = (int) ((float) progress / max * 100.0f);
+
+			StringBuilder text = new StringBuilder();
+			text.append("Progress: ");
+			text.append(percent);
+			text.append("%");
+
+			if (slept > 0)
+				setVisible(true);
+
+			if (progress(text.toString()))
+			{
+				setVisible(false);
+				dispose();
+				return true;
+			}
+
+			return false;
+		}
+	}
 
 	public static void main(String[] args) {
 		String selectedPath;
@@ -1938,6 +2013,8 @@ public void onPageContentsChange(Pixmap pixmap, Rect[] links, String[] linkURIs,
 		this.linkURIs = linkURIs;
 		this.hits = hits;
 		redraw();
+		if (renderMeter != null)
+			renderMeter.done();
 	}
 	public void onSearchStart(Location startPage, Location finalPage, int direction, String needle) {
 		searchField.setEnabled(false);

platform/java/example/ViewerCore.java

@@ -408,7 +408,7 @@ public void exception(Throwable t) {
 		});
 	}
 
-	public void renderPage(final Matrix ctm, final Rect bbox, final boolean icc, final int antialias, final boolean invert, final boolean tint, final int tintBlack, final int tintWhite, final OnException onException) {
+	public void renderPage(final Matrix ctm, final Rect bbox, final boolean icc, final int antialias, final boolean invert, final boolean tint, final int tintBlack, final int tintWhite, final Cookie cookie, final OnException onException) {
 		worker.add(new Worker.Task() {
 			Pixmap pixmap = null;
 			Rect[] links = null;
@@ -452,7 +452,7 @@ public void work() {
 				Context.setAntiAliasLevel(antialias);
 
 				DrawDevice dev = new DrawDevice(pixmap);
-				page.run(dev, ctm, null);
+				page.run(dev, ctm, cookie);
 				dev.close();
 				dev.destroy();