tdf#91727 - Unwind non-dispatch of idle handlers.

This clobbers the functionality from commit:

06d731428ef6cf93c7333e8228bfb6088853b52f

make idle timers actually activate only when idle

Since now all rendering and re-sizing is done in idle handlers it
does effectively the opposite of what was intended. A better solution
would allow special-casing the processing of just rendering,
re-sizing and window management to spin for eg. progress bar
rendering.

Also add helpful debugging labels to the idle & timeouts.

Also cleanup the Idle vs. Scheduler handling.

Also ensure that starting an Idle triggers a mainloop wakeup.

Also add a unit test.

Change-Id: Ifb0756714378fdb790be599b93c7a3ac1f9209e6

3 files changed, 31 insertions, 11 deletions

diff --git a/vcl/source/app/idle.cxx b/vcl/source/app/idle.cxx
index 7fe239d199f7..0dd8593bff84 100644
--- a/vcl/source/app/idle.cxx
+++ b/vcl/source/app/idle.cxx
@@ -18,6 +18,8 @@
  */
 
 #include <vcl/idle.hxx>
+#include <vcl/timer.hxx>
+#include "svdata.hxx"
 
 void Idle::Invoke()
 {
@@ -31,7 +33,7 @@ Idle& Idle::operator=( const Idle& rIdle )
     return *this;
 }
 
-Idle::Idle() : Scheduler()
+Idle::Idle( const sal_Char *pDebugName ) : Scheduler( pDebugName )
 {
 }
 
@@ -40,4 +42,25 @@ Idle::Idle( const Idle& rIdle ) : Scheduler(rIdle)
     maIdleHdl = rIdle.maIdleHdl;
 }
 
+void Idle::Start()
+{
+    Scheduler::Start();
+    ImplSVData* pSVData = ImplGetSVData();
+    Timer::ImplStartTimer( pSVData, 0 );
+}
+
+bool Idle::ReadyForSchedule( bool bTimer )
+{
+    // tdf#91727 - We need to re-work this to allow only UI idle handlers
+    //             and not timeouts to be processed in some limited scenarios
+    (void)bTimer;
+    return true; // !bTimer
+}
+
+sal_uInt64 Idle::UpdateMinPeriod( sal_uInt64 /* nMinPeriod */, sal_uInt64 /* nTime */ )
+{
+    return 1;
+}
+
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/vcl/source/app/scheduler.cxx b/vcl/source/app/scheduler.cxx
index 20b11dc4c922..c3cea781e6b8 100644
--- a/vcl/source/app/scheduler.cxx
+++ b/vcl/source/app/scheduler.cxx
@@ -120,6 +120,7 @@ void Scheduler::ProcessTaskScheduling( bool bTimer )
     sal_uInt64         nMinPeriod = MAX_TIMER_PERIOD;
     pSVData->mnUpdateStack++;
 
+    // tdf#91727 - NB. bTimer is ultimately not used
     if ((pSchedulerData = ImplSchedulerData::GetMostImportantTask(bTimer)))
     {
         pSchedulerData->mnUpdateTime = nTime;
@@ -164,18 +165,12 @@ void Scheduler::ProcessTaskScheduling( bool bTimer )
         pSVData->mnTimerPeriod = MAX_TIMER_PERIOD;
     }
     else
+    {
         Timer::ImplStartTimer( pSVData, nMinPeriod );
+    }
     pSVData->mnUpdateStack--;
 }
 
-sal_uInt64 Scheduler::UpdateMinPeriod( sal_uInt64 nMinPeriod, sal_uInt64 nTime )
-{
-    // this period is only useful for timer
-    // so in this implementation it' only a pass through
-    (void)nTime;
-    return nMinPeriod;
-}
-
 void Scheduler::SetPriority( SchedulerPriority ePriority )
 {
     mePriority = ePriority;
@@ -235,8 +230,9 @@ Scheduler& Scheduler::operator=( const Scheduler& rScheduler )
     return *this;
 }
 
-Scheduler::Scheduler():
+Scheduler::Scheduler(const sal_Char *pDebugName):
     mpSchedulerData(NULL),
+    mpDebugName(pDebugName),
     mePriority(SchedulerPriority::HIGH),
     mbActive(false)
 {
@@ -244,6 +240,7 @@ Scheduler::Scheduler():
 
 Scheduler::Scheduler( const Scheduler& rScheduler ):
     mpSchedulerData(NULL),
+    mpDebugName(rScheduler.mpDebugName),
     mePriority(rScheduler.mePriority),
     mbActive(false)
 {
diff --git a/vcl/source/app/timer.cxx b/vcl/source/app/timer.cxx
index a49f4f5ed320..7d92283b6466 100644
--- a/vcl/source/app/timer.cxx
+++ b/vcl/source/app/timer.cxx
@@ -98,7 +98,7 @@ void Timer::InitSystemTimer()
     }
 }
 
-Timer::Timer() : Scheduler()
+Timer::Timer(const sal_Char *pDebugName) : Scheduler(pDebugName)
 {
     mnTimeout = 1;
     mbAuto = false;