recalculate vector layer extent only when necessary (fixes #6172)

Author: jef-n

src/core/qgsmaplayer.cpp

@@ -126,9 +126,9 @@ QString const & QgsMapLayer::source() const
   return mDataSource;
 }
 
-QgsRectangle QgsMapLayer::extent() const
+QgsRectangle QgsMapLayer::extent()
 {
-  return mLayerExtent;
+  return mExtent;
 }
 
 bool QgsMapLayer::draw( QgsRenderContext& rendererContext )
@@ -1247,3 +1247,8 @@ QString QgsMapLayer::metadata()
 {
   return QString();
 }
+
+void QgsMapLayer::setExtent( const QgsRectangle &r )
+{
+  mExtent = r;
+}

src/core/qgsmaplayer.h

@@ -110,8 +110,8 @@ class CORE_EXPORT QgsMapLayer : public QObject
      */
     virtual void drawLabels( QgsRenderContext& rendererContext );
 
-    /** Return the extent of the layer as a QRect */
-    QgsRectangle extent() const;
+    /** Return the extent of the layer */
+    virtual QgsRectangle extent();
 
     /*! Return the status of the layer. An invalid layer is one which has a bad datasource
      * or other problem. Child classes set this flag when intialized
@@ -126,7 +126,7 @@ class CORE_EXPORT QgsMapLayer : public QObject
     QString publicSource() const;
 
     /** Returns the source for the layer */
-    QString const & source() const;
+    QString const &source() const;
 
     /**
      * Returns the sublayers of this layer
@@ -390,6 +390,8 @@ class CORE_EXPORT QgsMapLayer : public QObject
     void dataChanged();
 
   protected:
+    /** Set the extent */
+    virtual void setExtent( const QgsRectangle &rect );
 
     /** set whether layer is valid or not - should be used in constructor.
         \note added in v1.5 */
@@ -421,7 +423,7 @@ class CORE_EXPORT QgsMapLayer : public QObject
     unsigned int mTransparencyLevel;
 
     /** Extent of the layer */
-    QgsRectangle mLayerExtent;
+    QgsRectangle mExtent;
 
     /** Indicates if the layer is valid and can be drawn */
     bool mValid;

src/core/qgspluginlayer.cpp

@@ -24,7 +24,7 @@ QString QgsPluginLayer::pluginLayerType()
   return mPluginLayerType;
 }
 
-void QgsPluginLayer::setExtent( const QgsRectangle & extent )
+void QgsPluginLayer::setExtent( const QgsRectangle &extent )
 {
-  mLayerExtent = extent;
+  mExtent = extent;
 }

src/core/qgsvectorlayer.cpp

@@ -105,6 +105,7 @@ QgsVectorLayer::QgsVectorLayer( QString vectorLayerPath,
     , mJoinBuffer( 0 )
     , mDiagramRenderer( 0 )
     , mDiagramLayerSettings( 0 )
+    , mValidExtent( false )
 {
   mActions = new QgsAttributeAction( this );
 
@@ -1461,10 +1462,24 @@ long QgsVectorLayer::updateFeatureCount() const
 
 void QgsVectorLayer::updateExtents()
 {
-  if ( !hasGeometryType() )
-    return;
+  mValidExtent = false;
+}
+
+void QgsVectorLayer::setExtent( const QgsRectangle &r )
+{
+  QgsMapLayer::setExtent( r );
+  mValidExtent = true;
+}
 
-  mLayerExtent.setMinimal();
+QgsRectangle QgsVectorLayer::extent()
+{
+  if ( mValidExtent )
+    return QgsMapLayer::extent();
+
+  QgsRectangle rect;
+
+  if ( !hasGeometryType() )
+    return rect;
 
   if ( !mDataProvider )
   {
@@ -1480,13 +1495,13 @@ void QgsVectorLayer::updateExtents()
     if ( mDataProvider->featureCount() != 0 )
     {
       QgsRectangle r = mDataProvider->extent();
-      mLayerExtent.combineExtentWith( &r );
+      rect.combineExtentWith( &r );
     }
 
     for ( QgsFeatureList::iterator it = mAddedFeatures.begin(); it != mAddedFeatures.end(); it++ )
     {
       QgsRectangle r = it->geometry()->boundingBox();
-      mLayerExtent.combineExtentWith( &r );
+      rect.combineExtentWith( &r );
     }
   }
   else
@@ -1499,19 +1514,23 @@ void QgsVectorLayer::updateExtents()
       if ( fet.geometry() )
       {
         QgsRectangle bb = fet.geometry()->boundingBox();
-        mLayerExtent.combineExtentWith( &bb );
+        rect.combineExtentWith( &bb );
       }
     }
   }
 
-  if ( mLayerExtent.xMinimum() > mLayerExtent.xMaximum() && mLayerExtent.yMinimum() > mLayerExtent.yMaximum() )
+  if ( rect.xMinimum() > rect.xMaximum() && rect.yMinimum() > rect.yMaximum() )
   {
     // special case when there are no features in provider nor any added
-    mLayerExtent = QgsRectangle(); // use rectangle with zero coordinates
+    rect = QgsRectangle(); // use rectangle with zero coordinates
   }
 
+  setExtent( rect );
+
   // Send this (hopefully) up the chain to the map canvas
   emit recalculateExtents();
+
+  return rect;
 }
 
 QString QgsVectorLayer::subsetString()
@@ -2819,10 +2838,7 @@ bool QgsVectorLayer::setDataProvider( QString const & provider )
       QString s = mbr.toString();
       QgsDebugMsg( "Extent of layer: " +  s );
       // store the extent
-      mLayerExtent.setXMaximum( mbr.xMaximum() );
-      mLayerExtent.setXMinimum( mbr.xMinimum() );
-      mLayerExtent.setYMaximum( mbr.yMaximum() );
-      mLayerExtent.setYMinimum( mbr.yMinimum() );
+      setExtent( mbr );
 
       // get and store the feature type
       mWkbType = mDataProvider->geometryType();

src/core/qgsvectorlayer.h

@@ -493,6 +493,9 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
     /** Draws the layer labels using coordinate transformation */
     void drawLabels( QgsRenderContext& rendererContext );
 
+    /** Return the extent of the layer as a QRect */
+    QgsRectangle extent();
+
     /** returns field list in the to-be-committed state */
     const QgsFieldMap &pendingFields() const;
 
@@ -745,6 +748,10 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
     void committedAttributeValuesChanges( const QString& layerId, const QgsChangedAttributesMap& changedAttributesValues );
     void committedGeometriesChanges( const QString& layerId, const QgsGeometryMap& changedGeometries );
 
+  protected:
+    /** Set the extent */
+    void setExtent( const QgsRectangle &rect );
+
   private:                       // Private methods
 
     /** vector layers are not copyable */
@@ -986,6 +993,8 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
 
     //stores infos about diagram placement (placement type, priority, position distance)
     QgsDiagramLayerSettings *mDiagramLayerSettings;
+
+    bool mValidExtent;
 };
 
 #endif

src/core/raster/qgsrasterlayer.cpp

@@ -693,7 +693,7 @@ bool QgsRasterLayer::draw( QgsRenderContext& rendererContext )
 
     try
     {
-      myProjectedLayerExtent = rendererContext.coordinateTransform()->transformBoundingBox( mLayerExtent );
+      myProjectedLayerExtent = rendererContext.coordinateTransform()->transformBoundingBox( extent() );
     }
     catch ( QgsCsException &cs )
     {
@@ -705,7 +705,7 @@ bool QgsRasterLayer::draw( QgsRenderContext& rendererContext )
   {
     QgsDebugMsg( "coordinateTransform not set" );
     myProjectedViewExtent = rendererContext.extent();
-    myProjectedLayerExtent = mLayerExtent;
+    myProjectedLayerExtent = extent();
   }
 
   QPainter* theQPainter = rendererContext.painter();
@@ -1691,10 +1691,7 @@ void QgsRasterLayer::setDataProvider( QString const & provider )
   QString s = mbr.toString();
   QgsDebugMsg( "Extent of layer: " + s );
   // store the extent
-  mLayerExtent.setXMaximum( mbr.xMaximum() );
-  mLayerExtent.setXMinimum( mbr.xMinimum() );
-  mLayerExtent.setYMaximum( mbr.yMaximum() );
-  mLayerExtent.setYMinimum( mbr.yMinimum() );
+  setExtent( mbr );
 
   mWidth = mDataProvider->xSize();
   mHeight = mDataProvider->ySize();
@@ -1704,9 +1701,6 @@ void QgsRasterLayer::setDataProvider( QString const & provider )
   QgsDebugMsg( "mLayerName: " + name() );
 
   mValidNoDataValue = mDataProvider->isNoDataValueValid();
-  if ( mValidNoDataValue )
-  {
-  }
 
   // set up the raster drawing style
   setDrawingStyle( MultiBandColor );  //sensible default