Animations of redocking widgets are broken

The problem is that when starting an animation, we delay it by starting
a 0-timer. That doesn't work on windows while dragging a native window.

Task-number: 260772
Reviewed-by: prasanth

1 files changed, 15 insertions, 2 deletions

diff --git a/src/corelib/animation/qabstractanimation.cpp b/src/corelib/animation/qabstractanimation.cpp
index e1b8509..31f0841 100644
--- a/src/corelib/animation/qabstractanimation.cpp
+++ b/src/corelib/animation/qabstractanimation.cpp
@@ -157,6 +157,19 @@
 
 #define DEFAULT_TIMER_INTERVAL 16
 
+#ifdef Q_WS_WIN
+    /// Fix for Qt 4.7
+    //on windows if you're currently dragging a widget an inner eventloop was started by the system
+    //to make sure that this timer is getting fired, we need to make sure to use the system timers
+    //that will send a WM_TIMER event. We do that by settings the timer interval to 11
+    //It is 11 because QEventDispatcherWin32Private::registerTimer specifically checks if the interval
+    //is greater than 10 to determine if it should use a system timer (or the multimedia timer).
+#define STARTSTOP_TIMER_DELAY 11
+#else
+#define STARTSTOP_TIMER_DELAY 0
+#endif
+
+
 QT_BEGIN_NAMESPACE
 
 Q_GLOBAL_STATIC(QThreadStorage<QUnifiedTimer *>, unifiedTimer)
@@ -217,7 +230,7 @@ void QUnifiedTimer::registerAnimation(QAbstractAnimation *animation)
     if (animations.contains(animation) || animationsToStart.contains(animation))
         return;
     animationsToStart << animation;
-    startStopAnimationTimer.start(0, this); // we delay the check if we should start/stop the global timer
+    startStopAnimationTimer.start(STARTSTOP_TIMER_DELAY, this); // we delay the check if we should start/stop the global timer
 }
 
 void QUnifiedTimer::unregisterAnimation(QAbstractAnimation *animation)
@@ -233,7 +246,7 @@ void QUnifiedTimer::unregisterAnimation(QAbstractAnimation *animation)
     } else {
         animationsToStart.removeOne(animation);
     }
-    startStopAnimationTimer.start(0, this); // we delay the check if we should start/stop the global timer
+    startStopAnimationTimer.start(STARTSTOP_TIMER_DELAY, this); // we delay the check if we should start/stop the global timer
 }