Invalidate cached image when layer's data or appearance is modified

Author: wonder-sk

python/gui/qgsmapcanvas.sip

@@ -79,6 +79,10 @@ class QgsMapCanvas : QGraphicsView
     //! @note added in 2.1
     bool isCachingEnabled() const;
 
+    //! Make sure to remove any rendered images from cache (does nothing if cache is not enabled)
+    //! @note added in 2.1
+    void clearCache();
+
     //! Set whether the layers are rendered in parallel or sequentially
     //! @note added in 2.1
     void setParallelRenderingEnabled( bool enabled );

src/app/qgisapp.cpp

@@ -5681,6 +5681,8 @@ void QgisApp::refreshMapCanvas()
 {
   //reload cached provider data
   QgsMapLayerRegistry::instance()->reloadAllLayers();
+
+  mMapCanvas->clearCache();
   //then refresh
   mMapCanvas->refresh();
 }
@@ -6726,7 +6728,7 @@ void QgisApp::adjustBrightnessContrast( int delta, bool updateBrightness )
     brightnessFilter->setContrast( brightnessFilter->contrast() + delta );
   }
 
-  mMapCanvas->refresh();
+  myRasterLayer->triggerRepaint();
 }
 
 void QgisApp::helpContents()

src/core/qgsmaplayer.h

@@ -407,8 +407,8 @@ class CORE_EXPORT QgsMapLayer : public QObject
      */
     void layerCrsChanged();
 
-    /** This signal should be connected with the slot QgsMapCanvas::refresh()
-     * \todo to be removed - GUI dependency
+    /** By emitting this signal the layer tells that either appearance or content have been changed
+     * and any view showing the rendered layer should refresh itself.
      */
     void repaintRequested();
 

src/core/qgsvectorlayer.cpp

@@ -168,6 +168,8 @@ QgsVectorLayer::QgsVectorLayer( QString vectorLayerPath,
 
   connect( this, SIGNAL( selectionChanged( QgsFeatureIds, QgsFeatureIds, bool ) ), this, SIGNAL( selectionChanged() ) );
 
+  connect( this, SIGNAL( selectionChanged( QgsFeatureIds, QgsFeatureIds, bool ) ), this, SIGNAL( repaintRequested() ) );
+
   connect( QgsProject::instance()->relationManager(), SIGNAL( relationsLoaded() ), this, SLOT( onRelationsLoaded() ) );
 } // QgsVectorLayer ctor
 
@@ -888,6 +890,9 @@ bool QgsVectorLayer::setSubsetString( QString subset )
   mDataSource = mDataProvider->dataSourceUri();
   updateExtents();
 
+  if ( res )
+    emit repaintRequested();
+
   return res;
 }
 
@@ -2325,6 +2330,8 @@ bool QgsVectorLayer::commitChanges()
   updateFields();
   mDataProvider->updateExtents();
 
+  emit repaintRequested();
+
   return success;
 }
 
@@ -2366,6 +2373,7 @@ bool QgsVectorLayer::rollBack( bool deleteBuffer )
     mCache->deleteCachedGeometries();
   }
 
+  emit repaintRequested();
   return true;
 }
 

src/core/raster/qgsrasterlayer.cpp

@@ -931,6 +931,8 @@ void QgsRasterLayer::setContrastEnhancement( QgsContrastEnhancement::ContrastEnh
     if ( myEnhancements.value( 1 ) ) myMultiBandRenderer->setGreenContrastEnhancement( myEnhancements.value( 1 ) );
     if ( myEnhancements.value( 2 ) ) myMultiBandRenderer->setBlueContrastEnhancement( myEnhancements.value( 2 ) );
   }
+
+  emit repaintRequested();
 }
 
 void QgsRasterLayer::setDefaultContrastEnhancement()

src/gui/qgsmapcanvas.cpp

@@ -370,7 +370,7 @@ void QgsMapCanvas::setLayerSet( QList<QgsMapCanvasLayer> &layers )
       // Add check if vector layer when disconnecting from selectionChanged slot
       // Ticket #811 - racicot
       QgsMapLayer *currentLayer = layer( i );
-      disconnect( currentLayer, SIGNAL( repaintRequested() ), this, SLOT( refresh() ) );
+      disconnect( currentLayer, SIGNAL( repaintRequested() ), this, SLOT( layerRequestedRepaint() ) );
       QgsVectorLayer *isVectLyr = qobject_cast<QgsVectorLayer *>( currentLayer );
       if ( isVectLyr )
       {
@@ -385,7 +385,7 @@ void QgsMapCanvas::setLayerSet( QList<QgsMapCanvasLayer> &layers )
       // Add check if vector layer when connecting to selectionChanged slot
       // Ticket #811 - racicot
       QgsMapLayer *currentLayer = layer( i );
-      connect( currentLayer, SIGNAL( repaintRequested() ), this, SLOT( refresh() ) );
+      connect( currentLayer, SIGNAL( repaintRequested() ), this, SLOT( layerRequestedRepaint() ) );
       QgsVectorLayer *isVectLyr = qobject_cast<QgsVectorLayer *>( currentLayer );
       if ( isVectLyr )
       {
@@ -509,6 +509,12 @@ bool QgsMapCanvas::isCachingEnabled() const
   return mCache != 0;
 }
 
+void QgsMapCanvas::clearCache()
+{
+  if ( mCache )
+    mCache->clear();
+}
+
 void QgsMapCanvas::setParallelRenderingEnabled( bool enabled )
 {
   mUseParallelRendering = enabled;
@@ -640,6 +646,19 @@ void QgsMapCanvas::refreshMap()
   mMapUpdateTimer.start();
 }
 
+void QgsMapCanvas::layerRequestedRepaint()
+{
+  // make sure to clear the cached image
+  if ( mCache )
+  {
+    QgsMapLayer* layer = qobject_cast<QgsMapLayer*>( sender() );
+    if ( layer )
+      mCache->setCacheImage( layer->id(), QImage() );
+  }
+
+  refresh();
+}
+
 void QgsMapCanvas::rendererJobFinished()
 {
   qDebug("CANVAS finish! %d", !mJobCancelled );

src/gui/qgsmapcanvas.h

@@ -150,6 +150,10 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
     //! @note added in 2.1
     bool isCachingEnabled() const;
 
+    //! Make sure to remove any rendered images from cache (does nothing if cache is not enabled)
+    //! @note added in 2.1
+    void clearCache();
+
     //! Set whether the layers are rendered in parallel or sequentially
     //! @note added in 2.1
     void setParallelRenderingEnabled( bool enabled );
@@ -367,6 +371,9 @@ class GUI_EXPORT QgsMapCanvas : public QGraphicsView
 
     void refreshMap();
 
+    //! Layer says something has changed that affects its appearance
+    void layerRequestedRepaint();
+
   signals:
     /** Let the owner know how far we are with render operations */
     //! @deprecated since 2.1 - already unused in 2.0 anyway