OSX fix updates during resize

While resizing MacOS suspends the NSDefaultRunLoopMode. So in this
caae we can't post to the system event loop, but must use timers
to restart ourself.

Since the timer itself is scheduled on the NSEventTrackingRunLoopMode
it' also triggers on resize events.

There is still some minor glitch: when resizing too fast some part of
LibreOffice isn't painted, while the left mouse button is down.

Since there isn't any layouting triggered by the mouse up, there has
to be an other inconsistency.

Change-Id: I3ccba78bd23ec8526f21e7b93b027f3d3279f901

vcl/README.scheduler

@@ -91,9 +91,14 @@ can be added to the scheduler reasonably.
 
 == MacOS implementation details ==
 
-Generally the Scheduler is handled as expected. There is a workaround for a
-problem for pushing tasks to an empty queue, as [NSApp postEvent: ...
-atStart: NO] doesn't append the event, if the message queue is empty.
+Generally the Scheduler is handled as expected, except on resize, which is
+handled with different runloop-modes in MacOS. In case of a resize, the normal
+runloop is suspended in sendEvent, so we can't call the scheduler via posted
+main loop-events. Instead the schedule the timer again.
+
+There is also a workaround for a problem for pushing tasks to an empty queue,
+as [NSApp postEvent: ... atStart: NO] doesn't append the event, if the
+message queue is empty.
 
 Probably that's the reason, why some code comments spoke of lost events and
 there was some distinct additional event processing implemented.

vcl/inc/osx/salinst.h

@@ -74,6 +74,7 @@ public:
     std::list< SalUserEvent >               maUserEvents;
     osl::Mutex                              maUserEventListMutex;
     osl::Condition                          maWaitingYieldCond;
+    bool                                    mbIsLiveResize;
 
     static std::list<const ApplicationEvent*> aAppEventList;
 

vcl/osx/salframeview.mm

@@ -533,6 +533,17 @@ private:
 
 -(void)drawRect: (NSRect)aRect
 {
+    if( GetSalData()->mpFirstInstance )
+    {
+        const bool bIsLiveResize = [self inLiveResize];
+        const bool bWasLiveResize = GetSalData()->mpFirstInstance->mbIsLiveResize;
+        if ( bWasLiveResize != bIsLiveResize )
+        {
+            GetSalData()->mpFirstInstance->mbIsLiveResize = bIsLiveResize;
+            Scheduler::ProcessTaskScheduling();
+        }
+    }
+
     // HOTFIX: #i93512# prevent deadlocks if any other thread already has the SalYieldMutex
     TryGuard aTryGuard;
     if( !aTryGuard.IsGuarded() )

vcl/osx/salinst.cxx

@@ -347,6 +347,7 @@ void DestroySalInstance( SalInstance* pInst )
 AquaSalInstance::AquaSalInstance()
  : maUserEventListMutex()
  , maWaitingYieldCond()
+ , mbIsLiveResize( false )
 {
     mpSalYieldMutex = new SalYieldMutex;
     mpSalYieldMutex->acquire();

vcl/osx/salnstimer.mm

@@ -30,7 +30,13 @@
 -(void)timerElapsed:(NSTimer*)pTimer
 {
     (void)pTimer;
-    ImplNSAppPostEvent( AquaSalInstance::DispatchTimerEvent, YES );
+    // nil the timer, as it is just invalidated after the firing function
+    AquaSalTimer::pRunningTimer = nil;
+    const AquaSalInstance *pInst = GetSalData()->mpFirstInstance;
+    if (pInst->mbIsLiveResize)
+        AquaSalTimer::handleDispatchTimerEvent();
+    else
+        ImplNSAppPostEvent( AquaSalInstance::DispatchTimerEvent, YES );
 }
 
 @end

vcl/osx/saltimer.cxx

@@ -83,7 +83,7 @@ static void ImplSalStartTimer( sal_uLong nMS )
         return;
     }
 
-    if ( 0 == nMS )
+    if ( 0 == nMS && !pSalData->mpFirstInstance->mbIsLiveResize )
     {
         ImplSalStopTimer();
         ImplNSAppPostEvent( AquaSalInstance::DispatchTimerEvent, NO );
@@ -93,7 +93,7 @@ static void ImplSalStartTimer( sal_uLong nMS )
         NSTimeInterval aTI = double(nMS) / 1000.0;
         if( AquaSalTimer::pRunningTimer != nil )
         {
-            if (rtl::math::approxEqual(
+            if ([AquaSalTimer::pRunningTimer isValid] && rtl::math::approxEqual(
                     [AquaSalTimer::pRunningTimer timeInterval], aTI))
             {
                 // set new fire date