Merge lp:~fboucault/unity-2d/dash_no_unload_page into lp:unity-2d

[Florian Boucault]

[dash] Do not unload the current page when exiting it. That does not change
the user experience at all and improves the speed at which the dash opens
up in a number of cases.

Reference: https://bugs.launchpad.net/unity-2d/+bug/881756

The workarounds crashers in the code removed by this change were still valid.

[Florian Boucault (fboucault)]

"The workarounds crashers in the code removed by this change were still valid." means that I tested that without the workarounds the crashers were still occuring.

The first one is fixed in Qt 4.8 so we won't have to worry about it for much longer:
https://bugs.launchpad.net/ubuntu/+source/unity-2d/+bug/817896
https://bugreports.qt.nokia.com/browse/QTBUG-20692

The second one is probably a crasher happening because of one of the Ubuntu patches we carry since upstream cannot reproduce it:
https://bugs.launchpad.net/ubuntu/+source/unity-2d/+bug/836498
https://bugreports.qt.nokia.com/browse/QTBUG-22776

[Gerry Boland (gerboland)]

I don't approve of removing the workarounds until they're unnecessary. I suggest that we hold off merging this patch until Qt4.8 is introduced, and we investigation the root cause of the second crasher (RTL).

[Florian Boucault (fboucault)]

Well they are unnecessary because the code that needed them is also removed by the merge request.

[Gerry Boland (gerboland)]

Ah ok, I misunderstood what you were saying. Performance is improved visibly, this is great. Thank you

review: Approve

=== modified file 'places/dash.qml'
--- places/dash.qml	2011-11-29 12:13:27 +0000
+++ places/dash.qml	2011-12-06 21:08:24 +0000
@@ -50,35 +50,6 @@
             DashDeclarativeView.DesktopMode : DashDeclarativeView.FullScreenMode
     }
 
-    /* Unload the current page when closing the dash */
-    Connections {
-        target: dashView
-        onActiveChanged: {
-            if (!dashView.active) {
-                /* FIXME: currentPage needs to stop pointing to pageLoader.item
-                          that is about to be invalidated otherwise a crash
-                          occurs because SearchEntry has a binding that refers
-                          to currentPage and tries to access it.
-                   Ref.: https://bugs.launchpad.net/ubuntu/+source/unity-2d/+bug/817896
-                         https://bugreports.qt.nokia.com/browse/QTBUG-20692
-                */
-                deactivateActiveLens()
-                currentPage = undefined
-                // Delay the following instruction by 1 millisecond using a
-                // timer. This is enough to work around a crash that happens
-                // when the layout is mirrored (RTL locales). See QTBUG-22776
-                // for details.
-                //pageLoader.source = ""
-                delayPageLoaderReset.restart()
-            }
-        }
-    }
-    Timer {
-        id: delayPageLoaderReset
-        interval: 1
-        onTriggered: pageLoader.source = ""
-    }
-
     function activatePage(page) {
         /* Always give the focus to the search entry when switching pages */
         search_entry.focus = true