make idle timers actually activate only when idle

Without this, they can activate after any call to the event processing,
so they may activate in cases such as when updating progressbar while
loading a document, or on repeated user input (so things like showing
spellchecking get updated when the app is busy redrawing). This change
makes idle timers activate only when there's nothing more for the event
loop to process. It's a bit of a question if this doesn't break something
that happens to expect idle timers to be not-really-idle timers, but oh well.

No change for non-X11 platforms, as there's I don't know how to check
the event queues.

Change-Id: I074a88f2f5eeb4b456a11916a0ec2ad6f54dfbab

2 files changed, 24 insertions, 3 deletions

diff --git a/vcl/unx/generic/app/saldata.cxx b/vcl/unx/generic/app/saldata.cxx
index 317c16e16452..2a90eb7dc49d 100644
--- a/vcl/unx/generic/app/saldata.cxx
+++ b/vcl/unx/generic/app/saldata.cxx
@@ -336,6 +336,7 @@ void X11SalData::PopXErrorLevel()
 }
 
 SalXLib::SalXLib()
+    : blockIdleTimeout( false )
 {
     m_aTimeout.tv_sec       = 0;
     m_aTimeout.tv_usec      = 0;
@@ -646,8 +647,20 @@ bool SalXLib::CheckTimeout( bool bExecuteTimers )
                 *  timers are being dispatched.
                 */
                 m_aTimeout += m_nTimeoutMS;
+                // Determine if the app is idle (for idle timers). If there's user input pending,
+                // if there's IO pending or if we're called inside a temporary yield (=blockIdleTimeout),
+                // then the app is not idle.
+                bool idle = true;
+                if( blockIdleTimeout || XPending( vcl_sal::getSalDisplay(GetGenericData())->GetDisplay()))
+                    idle = false;
+                for ( int nFD = 0; idle && nFD < nFDs_; nFD++ )
+                {
+                    YieldEntry* pEntry = &(yieldTable[nFD]);
+                    if ( pEntry->fd && pEntry->HasPendingEvent())
+                        idle = false;
+                }
                 // notify
-                GetX11SalData()->Timeout();
+                GetX11SalData()->Timeout( idle );
             }
         }
     }
@@ -656,6 +669,7 @@ bool SalXLib::CheckTimeout( bool bExecuteTimers )
 
 void SalXLib::Yield( bool bWait, bool bHandleAllCurrentEvents )
 {
+    blockIdleTimeout = !bWait;
     // check for timeouts here if you want to make screenshots
     static char* p_prioritize_timer = getenv ("SAL_HIGHPRIORITY_REPAINT");
     if (p_prioritize_timer != NULL)
@@ -674,7 +688,10 @@ void SalXLib::Yield( bool bWait, bool bHandleAllCurrentEvents )
             {
                 pEntry->HandleNextEvent();
                 if( ! bHandleAllCurrentEvents )
+                {
+                    blockIdleTimeout = false;
                     return;
+                }
             }
         }
     }
@@ -746,7 +763,10 @@ void SalXLib::Yield( bool bWait, bool bHandleAllCurrentEvents )
 
         // someone-else has done the job for us
         if (nFound == 0)
+        {
+            blockIdleTimeout = false;
             return;
+        }
 
         for ( int nFD = 0; nFD < nFDs_; nFD++ )
         {
@@ -772,6 +792,7 @@ void SalXLib::Yield( bool bWait, bool bHandleAllCurrentEvents )
             }
         }
     }
+    blockIdleTimeout = false;
 }
 
 void SalXLib::Wakeup()
diff --git a/vcl/unx/generic/app/saltimer.cxx b/vcl/unx/generic/app/saltimer.cxx
index 19b44955cfe0..fc55afb85c48 100644
--- a/vcl/unx/generic/app/saltimer.cxx
+++ b/vcl/unx/generic/app/saltimer.cxx
@@ -29,11 +29,11 @@
 #include <unx/saltimer.h>
 #include <unx/salinst.h>
 
-void X11SalData::Timeout() const
+void X11SalData::Timeout( bool idle ) const
 {
     ImplSVData* pSVData = ImplGetSVData();
     if( pSVData->mpSalTimer )
-        pSVData->mpSalTimer->CallCallback();
+        pSVData->mpSalTimer->CallCallback( idle );
 }
 
 void SalXLib::StopTimer()