[e4-dev] Contacts Demo 'Fading' patch

[Eric Moffatt <emoffatt@xxxxxxxxxx>]

Here's a patch that I cribbed from the
'FaderAnimationFeedback' in 3.5 that adds a slick 'cross fade' effect to
the CSS style switching. Try it out. ..;-).



Back to compatibility,
Eric
### Eclipse Workspace Patch 1.0
#P org.eclipse.e4.demo.contacts
Index: src/org/eclipse/e4/demo/contacts/handlers/ThemeUtil.java
===================================================================
RCS file: /cvsroot/eclipse/e4/org.eclipse.e4.ui/examples/org.eclipse.e4.demo.contacts/src/org/eclipse/e4/demo/contacts/handlers/ThemeUtil.java,v
retrieving revision 1.4
diff -u -r1.4 ThemeUtil.java
--- src/org/eclipse/e4/demo/contacts/handlers/ThemeUtil.java	29 May 2009 12:04:15 -0000	1.4
+++ src/org/eclipse/e4/demo/contacts/handlers/ThemeUtil.java	8 Jun 2009 17:26:48 -0000
@@ -21,11 +21,55 @@
 import org.eclipse.e4.ui.css.core.engine.CSSEngine;
 import org.eclipse.e4.workbench.ui.IWorkbench;
 import org.eclipse.e4.workbench.ui.internal.Workbench;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.graphics.GC;
+import org.eclipse.swt.graphics.Image;
+import org.eclipse.swt.graphics.Rectangle;
 import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Shell;
 
 public class ThemeUtil {
 
+	private static Shell initAnimation(Shell baseShell) {
+		Rectangle psRect = baseShell.getBounds();
+		Shell animationShell = new Shell(baseShell, SWT.NO_TRIM | SWT.ON_TOP);			
+		animationShell.setBounds(psRect);
+
+		// Capture the background image
+//		long startTime = System.currentTimeMillis();
+		Image backingStore = new Image(animationShell.getDisplay(), psRect);
+		GC gc = new GC(baseShell.getDisplay());
+		gc.copyArea(backingStore, psRect.x, psRect.y);
+		gc.dispose();
+		
+		animationShell.setAlpha(255);
+		animationShell.setBackgroundImage(backingStore);
+		animationShell.setVisible(true);
+//		System.out.println("Capture time = " + (System.currentTimeMillis()- startTime)); //$NON-NLS-1$
+		
+		return animationShell;
+	}
+	
+	private static void runAnimation(Shell animationShell) {
+		Rectangle ab = animationShell.getBounds();
+		long area = ab.width * ab.height;
+		
+		// Naive attempt to use fewer steps on large shells
+		int stepSize = 25;
+		if (area < 500000) stepSize = 10;
+		else if (area < 1000000) stepSize = 17;
+
+		// 'Fade' the animation shell 
+		while (animationShell.getAlpha() > 0) {
+			int newAlpha = (int) (animationShell.getAlpha() - stepSize);
+			if (newAlpha < 0) newAlpha = 0;
+			animationShell.setAlpha(newAlpha);
+			animationShell.update();
+		}
+		animationShell.getBackgroundImage().dispose();
+		animationShell.dispose();
+	}
+	
 	public static void switchTheme(IWorkbench workbench, final String css) {
 		if (workbench instanceof Workbench) {
 			Workbench wb = (Workbench) workbench;
@@ -40,12 +84,17 @@
 						URL url = FileLocator.resolve(new URL(
 								"platform:/plugin/org.eclipse.e4.demo.contacts/css/"
 										+ css));
+						
+						Shell animationShell = initAnimation(shell);
 
 						InputStreamReader streamReader = new InputStreamReader(
 								url.openStream());
 						engine.reset();
 						engine.parseStyleSheet(streamReader);
 						engine.applyStyles(shell, true, false);
+						shell.update();
+						
+						runAnimation(animationShell);
 					} catch (MalformedURLException e) {
 						// TODO Auto-generated catch block
 						e.printStackTrace();