Also delay initial preview job by a short timeout

nyalldawson · nyalldawson · commit 628a1b096b26 · 2017-08-17T23:50:32.000+10:00
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;
 

Original file line number	Diff line number	Diff line change
`@@ -2132,7 +2132,7 @@ const QgsLabelingEngineSettings &QgsMapCanvas::labelingEngineSettings() const`
`2132`	`2132`	`void QgsMapCanvas::startPreviewJobs()`
`2133`	`2133`	`{`
`2134`	`2134`	`stopPreviewJobs(); //just in case still running`
`2135`		`- startPreviewJob( 0 );`
	`2135`	`+ schedulePreviewJob( 0 );`
`2136`	`2136`	`}`
`2137`	`2137`
`2138`	`2138`	`void QgsMapCanvas::startPreviewJob( int number )`
`@@ -2167,15 +2167,7 @@ void QgsMapCanvas::startPreviewJob( int number )`
`2167`	`2167`
`2168`	`2168`	`if ( number < 8 )`
`2169`	`2169`	`{`
`2170`		`- mPreviewTimer.setSingleShot( true );`
`2171`		`- mPreviewTimer.setInterval( 250 );`
`2172`		`- disconnect( mPreviewTimerConnection );`
`2173`		`- mPreviewTimerConnection = connect( &mPreviewTimer, &QTimer::timeout, [ = ]()`
`2174`		`- {`
`2175`		`- startPreviewJob( number + 1 );`
`2176`		`- }`
`2177`		`- );`
`2178`		`- mPreviewTimer.start();`
	`2170`	`+ schedulePreviewJob( number + 1 );`
`2179`	`2171`	`}`
`2180`	`2172`	`}`
`2181`	`2173`
`@@ -2194,3 +2186,16 @@ void QgsMapCanvas::stopPreviewJobs()`
`2194`	`2186`	`}`
`2195`	`2187`	`mPreviewJobs.clear();`
`2196`	`2188`	`}`
	`2189`	`+`
	`2190`	`+void QgsMapCanvas::schedulePreviewJob( int number )`
	`2191`	`+{`
	`2192`	`+ mPreviewTimer.setSingleShot( true );`
	`2193`	`+ mPreviewTimer.setInterval( 250 );`
	`2194`	`+ disconnect( mPreviewTimerConnection );`
	`2195`	`+ mPreviewTimerConnection = connect( &mPreviewTimer, &QTimer::timeout, [ = ]()`
	`2196`	`+ {`
	`2197`	`+ startPreviewJob( number );`
	`2198`	`+ }`
	`2199`	`+ );`
	`2200`	`+ mPreviewTimer.start();`
	`2201`	`+}`