Ensure all layer render subclasses correctly return false if the

rendering is aborted early
qgis · Jan 28, 2021 · a138921 · a138921
1 parent 0eaa986
commit a138921
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Showing 7 changed files with 21 additions and 7 deletions.
diff --git a/python/core/auto_generated/qgsmaplayerrenderer.sip.in b/python/core/auto_generated/qgsmaplayerrenderer.sip.in
@@ -50,7 +50,10 @@ Constructor for QgsMapLayerRenderer, with the associated ``layerID`` and render
 
     virtual bool render() = 0;
 %Docstring
-Do the rendering (based on data stored in the class)
+Do the rendering (based on data stored in the class).
+
+Returns ``True`` if the layer was completely rendered successfully (i.e. the render
+was not canceled early).
 %End
 
     virtual bool forceRasterRender() const;

diff --git a/src/core/annotations/qgsannotationlayerrenderer.cpp b/src/core/annotations/qgsannotationlayerrenderer.cpp
@@ -49,14 +49,18 @@ bool QgsAnnotationLayerRenderer::render()
 {
   QgsRenderContext &context = *renderContext();
 
+  bool canceled = false;
   for ( QgsAnnotationItem *item : qgis::as_const( mItems ) )
   {
     if ( mFeedback->isCanceled() )
+    {
+      canceled = true;
       break;
+    }
 
     item->render( context, mFeedback.get() );
   }
-  return true;
+  return !canceled;
 }
 
 bool QgsAnnotationLayerRenderer::forceRasterRender() const

diff --git a/src/core/mesh/qgsmeshlayerrenderer.cpp b/src/core/mesh/qgsmeshlayerrenderer.cpp
@@ -300,7 +300,7 @@ bool QgsMeshLayerRenderer::render()
   renderMesh();
   renderVectorDataset();
 
-  return true;
+  return !renderContext()->renderingStopped();
 }
 
 bool QgsMeshLayerRenderer::forceRasterRender() const

diff --git a/src/core/pointcloud/qgspointcloudlayerrenderer.cpp b/src/core/pointcloud/qgspointcloudlayerrenderer.cpp
@@ -159,11 +159,13 @@ bool QgsPointCloudLayerRenderer::render()
 
   // drawing
   int nodesDrawn = 0;
+  bool canceled = false;
   for ( const IndexedPointCloudNode &n : nodes )
   {
     if ( context.renderContext().renderingStopped() )
     {
       QgsDebugMsgLevel( "canceled", 2 );
+      canceled = true;
       break;
     }
     std::unique_ptr<QgsPointCloudBlock> block( pc->nodeData( n, request ) );
@@ -183,7 +185,7 @@ bool QgsPointCloudLayerRenderer::render()
 
   mRenderer->stopRender( context );
 
-  return true;
+  return !canceled;
 }
 
 bool QgsPointCloudLayerRenderer::forceRasterRender() const

diff --git a/src/core/qgsmaplayerrenderer.h b/src/core/qgsmaplayerrenderer.h
@@ -62,7 +62,12 @@ class CORE_EXPORT QgsMapLayerRenderer
 
     virtual ~QgsMapLayerRenderer() = default;
 
-    //! Do the rendering (based on data stored in the class)
+    /**
+     * Do the rendering (based on data stored in the class).
+     *
+     * Returns TRUE if the layer was completely rendered successfully (i.e. the render
+     * was not canceled early).
+     */
     virtual bool render() = 0;
 
     /**

diff --git a/src/core/raster/qgsrasterlayerrenderer.cpp b/src/core/raster/qgsrasterlayerrenderer.cpp
@@ -336,7 +336,7 @@ bool QgsRasterLayerRenderer::render()
   QgsDebugMsgLevel( QStringLiteral( "total raster draw time (ms):     %1" ).arg( time.elapsed(), 5 ), 4 );
   mReadyToCompose = true;
 
-  return true;
+  return !mFeedback->isCanceled();
 }
 
 QgsFeedback *QgsRasterLayerRenderer::feedback() const

diff --git a/src/core/vector/qgsvectorlayerrenderer.cpp b/src/core/vector/qgsvectorlayerrenderer.cpp
@@ -230,7 +230,7 @@ bool QgsVectorLayerRenderer::render()
   }
 
   mReadyToCompose = true;
-  return res;
+  return res && !renderContext()->renderingStopped();
 }
 
 bool QgsVectorLayerRenderer::renderInternal( QgsFeatureRenderer *renderer )