Also delay initial preview job by a short timeout

qgis · Aug 17, 2017 · 628a1b0 · 628a1b0
1 parent 6c17577
commit 628a1b0
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Showing 2 changed files with 16 additions and 10 deletions.
diff --git a/src/gui/qgsmapcanvas.cpp b/src/gui/qgsmapcanvas.cpp
@@ -2132,7 +2132,7 @@ const QgsLabelingEngineSettings &QgsMapCanvas::labelingEngineSettings() const
 void QgsMapCanvas::startPreviewJobs()
 {
   stopPreviewJobs(); //just in case still running
-  startPreviewJob( 0 );
+  schedulePreviewJob( 0 );
 }
 
 void QgsMapCanvas::startPreviewJob( int number )
@@ -2167,15 +2167,7 @@ void QgsMapCanvas::startPreviewJob( int number )
 
   if ( number < 8 )
   {
-    mPreviewTimer.setSingleShot( true );
-    mPreviewTimer.setInterval( 250 );
-    disconnect( mPreviewTimerConnection );
-    mPreviewTimerConnection = connect( &mPreviewTimer, &QTimer::timeout, [ = ]()
-    {
-      startPreviewJob( number + 1 );
-    }
-                                     );
-    mPreviewTimer.start();
+    schedulePreviewJob( number + 1 );
   }
 }
 
@@ -2194,3 +2186,16 @@ void QgsMapCanvas::stopPreviewJobs()
   }
   mPreviewJobs.clear();
 }
+
+void QgsMapCanvas::schedulePreviewJob( int number )
+{
+  mPreviewTimer.setSingleShot( true );
+  mPreviewTimer.setInterval( 250 );
+  disconnect( mPreviewTimerConnection );
+  mPreviewTimerConnection = connect( &mPreviewTimer, &QTimer::timeout, [ = ]()
+  {
+    startPreviewJob( number );
+  }
+                                   );
+  mPreviewTimer.start();
+}
diff --git a/src/gui/qgsmapcanvas.h b/src/gui/qgsmapcanvas.h
@@ -882,6 +882,7 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
 
     void startPreviewJobs();
     void stopPreviewJobs();
+    void schedulePreviewJob( int number );
 
     friend class TestQgsMapCanvas;