Merge lp:~vanvugt/compiz/fix-1047168 into lp:compiz/0.9.8

[Daniel van Vugt]

Ensure unredirected windows get redirected if windows are being transformed,
like in scale mode.
(LP: #1047168)

Ensure unredirected windows get redirected if windows are being transformed,
like in scale mode.
(LP: #1047168)

[Sam Spilsbury (smspillaz)]

27 + if (!region.isEmpty () ||
28 + (mask & PAINT_SCREEN_FULL_MASK) ||
29 + (mask & PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS_MASK))

This indicates to me that the fullscreen window unredirection code is living in the wrong place. It is probably a state machine that should be updated whenever window positions and sizes are changed. It probably also makes sense to force redirection where a window is transformed (and we can detect this in the occlusion pass, which should also be moved up above paintOutputs). What I'm proposing though is a fairly big change and we should leave it until next cycle. Until now this will do.

review: Approve

[Daniel van Vugt (vanvugt)]

I have tried moving that code before and found it to be exceptionally fragile for some reason. But I agree reredirect/unredirect should theoretically be done elsewhere.

=== modified file 'plugins/opengl/src/paint.cpp'
--- plugins/opengl/src/paint.cpp	2012-09-18 08:05:55 +0000
+++ plugins/opengl/src/paint.cpp	2012-09-21 06:08:19 +0000
@@ -352,6 +352,7 @@
 	     */
 	    if (unredirectFS &&
 		!(mask & PAINT_SCREEN_TRANSFORMED_MASK) &&
+		!(mask & PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS_MASK) &&
 		fs.isCoveredBy (w->region (), flags))
 	    {
 		unredirected.insert (w);
@@ -618,7 +619,19 @@
 
 	sTransform.toScreenSpace (output, -DEFAULT_Z_CAMERA);
 
-	if (!region.isEmpty ())
+	/*
+	 * Sometimes region might be empty but we still need to force the
+	 * repaint. This can happen when a fullscreen window is unredirected,
+	 * and damageScreen is called. CompositeScreen::handlePaintTimeout
+	 * then subtracts the whole screen of damage because it's an overlay
+	 * and we're left with an empty damage region.
+	 * Even when this happens we may want to force the repaint if
+	 * windows are getting transformed (and so the unredirected window
+	 * needs to be redirected again).
+	 */
+	if (!region.isEmpty () ||
+	    (mask & PAINT_SCREEN_FULL_MASK) ||
+	    (mask & PAINT_SCREEN_WITH_TRANSFORMED_WINDOWS_MASK))
 	    priv->paintOutputRegion (sTransform, region, output, mask);
 
 	return true;

=== modified file 'tests/manual/Unredirect.txt'
--- tests/manual/Unredirect.txt	2012-09-06 06:49:21 +0000
+++ tests/manual/Unredirect.txt	2012-09-21 06:08:19 +0000
@@ -75,3 +75,23 @@
 
 Expected Result:
   The gnome-terminal window should be visible on top.
+
+
+Unredirect cancelation by transformed windows (LP: #1047168)
+-------------------------------------------------------------
+Setup:
+#. Install Chromium or Chrome browser.
+#. Run ccsm and ensure the Scale plugin is loaded and "Initiate Window Picker"
+   is bound to Shift+Alt+Up.
+ 
+Actions:
+#. Open a Chrome/Chromium window.
+#. Open a gnome-terminal window (Ctrl+Alt+T)
+#. Move the gnome-terminal to the centre of the screen, above the Chrome
+   window.
+#. Click on the Chrome window and make it fullscreen (F11).
+#. Hold Shift+Alt and tap Up to engage scale mode. Keep holding Shift+Alt
+   for a few seconds.
+
+Expected Result:
+  Windows get scaled and you can see both the Chrome and Terminal windows.