Merge lp:~mc-return/unity/unity6.0.merge-fix1063249 into lp:unity/6.0

[MC Return]

Fixed fade-in behavior of Unity's showdesktop function. The windows were popping back in, fading out a bit and then fading in. This fix makes them fade back in smoothly.
Also added a manual test.

[Łukasz Zemczak (sil2100)]

WFM.

review: Approve

=== modified file 'manual-tests/WindowManagement.txt'
--- manual-tests/WindowManagement.txt	2012-07-25 08:38:07 +0000
+++ manual-tests/WindowManagement.txt	2012-10-15 09:41:22 +0000
@@ -67,4 +67,18 @@
 #. Tap the Super key again.
 #. Tap F11 to leave full screen.
 #. Press Super+S twice to force a full screen redraw.
++
+Show Desktop fades windows smoothly
+------------------------------------
+Tests visual regressions to the show desktop/restore windows behavior.
+
+Setup:
+
+Action:
+#. Open several windows.
+#. Press Super+D to show the desktop.
+#. Press Super+D again to restore the previous state.
+
+Expected Result:
+  All open windows must fade out and then fade back in smoothly, without any popping or pulsing effect.
 

=== modified file 'plugins/unityshell/src/UnityShowdesktopHandler.cpp'
--- plugins/unityshell/src/UnityShowdesktopHandler.cpp	2012-04-23 12:25:44 +0000
+++ plugins/unityshell/src/UnityShowdesktopHandler.cpp	2012-10-15 09:41:22 +0000
@@ -168,7 +168,7 @@
 
 void ShowdesktopHandler::PaintOpacity (unsigned short &opacity)
 {
-  if (progress_ == 1.0f || progress_ == 0.0f)
+  if (progress_ == 0.0f)
     opacity = std::numeric_limits <unsigned short>::max();
   else
     opacity *= (1.0f - progress_);