Support overriden layer styles also in the composer legend

Author: wonder-sk

python/core/composer/qgscomposermap.sip

@@ -755,6 +755,12 @@ class QgsComposerMap : QgsComposerItem
     /**Is emitted when the map has been prepared for atlas rendering, just before actual rendering*/
     void preparedForAtlas();
 
+    /** Emitted when layer style overrides are changed... a means to let
+     * associated legend items know they should update
+     * @note added in 2.10
+     */
+    void layerStyleOverridesChanged();
+
   public slots:
 
     /**Forces an update of the cached map image*/

python/core/layertree/qgslayertreemodel.sip

@@ -142,6 +142,13 @@ class QgsLayerTreeModel : QAbstractItemModel
     //! @note added in 2.6
     void legendMapViewData( double *mapUnitsPerPixel /Out/, int *dpi /Out/, double *scale /Out/ );
 
+    //! Get map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one
+    //! @note added in 2.10
+    QMap<QString, QString> layerStyleOverrides() const;
+    //! Set map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one
+    //! @note added in 2.10
+    void setLayerStyleOverrides( const QMap<QString, QString>& overrides );
+
     //! Return true if index represents a legend node (instead of layer node)
     //! @deprecated use index2legendNode()
     bool isIndexSymbologyNode( const QModelIndex& index ) const /Deprecated/;

src/core/composer/qgscomposerlegend.cpp

@@ -510,6 +510,7 @@ void QgsComposerLegend::setComposerMap( const QgsComposerMap* map )
     disconnect( mComposerMap, SIGNAL( destroyed( QObject* ) ), this, SLOT( invalidateCurrentMap() ) );
     disconnect( mComposerMap, SIGNAL( itemChanged() ), this, SLOT( updateFilterByMap() ) );
     disconnect( mComposerMap, SIGNAL( extentChanged() ), this, SLOT( updateFilterByMap() ) );
+    disconnect( mComposerMap, SIGNAL( layerStyleOverridesChanged() ), this, SLOT( mapLayerStyleOverridesChanged() ) );
   }
 
   mComposerMap = map;
@@ -519,6 +520,7 @@ void QgsComposerLegend::setComposerMap( const QgsComposerMap* map )
     QObject::connect( map, SIGNAL( destroyed( QObject* ) ), this, SLOT( invalidateCurrentMap() ) );
     QObject::connect( map, SIGNAL( itemChanged() ), this, SLOT( updateFilterByMap() ) );
     QObject::connect( map, SIGNAL( extentChanged() ), this, SLOT( updateFilterByMap() ) );
+    QObject::connect( map, SIGNAL( layerStyleOverridesChanged() ), this, SLOT( mapLayerStyleOverridesChanged() ) );
   }
 
   updateFilterByMap();
@@ -529,11 +531,33 @@ void QgsComposerLegend::invalidateCurrentMap()
   setComposerMap( 0 );
 }
 
+void QgsComposerLegend::mapLayerStyleOverridesChanged()
+{
+  if ( !mComposerMap )
+    return;
+
+  // map's style has been changed, so make sure to update the legend here
+
+  mLegendModel2->setLayerStyleOverrides( mComposerMap->layerStyleOverrides() );
+
+  foreach ( QgsLayerTreeLayer* nodeLayer, mLegendModel2->rootGroup()->findLayers() )
+    mLegendModel2->refreshLayerLegend( nodeLayer );
+
+  adjustBoxSize();
+  update();
+}
+
 void QgsComposerLegend::updateFilterByMap()
 {
   if ( isRemoved() )
     return;
 
+  if ( mComposerMap )
+    mLegendModel2->setLayerStyleOverrides( mComposerMap->layerStyleOverrides() );
+  else
+    mLegendModel2->setLayerStyleOverrides( QMap<QString, QString>() );
+
+
   if ( mComposerMap && mLegendFilterByMap )
   {
     int dpi = mComposition->printResolution();

src/core/composer/qgscomposerlegend.h

@@ -186,6 +186,9 @@ class CORE_EXPORT QgsComposerLegend : public QgsComposerItem
   private slots:
     void updateFilterByMap();
 
+    //! update legend in case style of associated map has changed
+    void mapLayerStyleOverridesChanged();
+
   private:
     QgsComposerLegend(); //forbidden
 

src/core/composer/qgscomposermap.cpp

@@ -1529,6 +1529,17 @@ void QgsComposerMap::storeCurrentLayerSet()
   }
 }
 
+
+void QgsComposerMap::setLayerStyleOverrides(const QMap<QString, QString>& overrides)
+{
+  if ( overrides == mLayerStyleOverrides )
+    return;
+
+  mLayerStyleOverrides = overrides;
+  emit layerStyleOverridesChanged();  // associated legends may listen to this
+}
+
+
 void QgsComposerMap::storeCurrentLayerStyles()
 {
   mLayerStyleOverrides.clear();

src/core/composer/qgscomposermap.h

@@ -255,7 +255,7 @@ class CORE_EXPORT QgsComposerMap : public QgsComposerItem
     /**Getter for stored overrides of styles for layers. @note added in 2.8 */
     QMap<QString, QString> layerStyleOverrides() const { return mLayerStyleOverrides; }
     /**Setter for stored overrides of styles for layers. @note added in 2.8 */
-    void setLayerStyleOverrides( const QMap<QString, QString>& overrides ) { mLayerStyleOverrides = overrides; }
+    void setLayerStyleOverrides( const QMap<QString, QString>& overrides );
     /**Stores the current layer styles into style overrides. @note added in 2.8 */
     void storeCurrentLayerStyles();
 
@@ -794,6 +794,12 @@ class CORE_EXPORT QgsComposerMap : public QgsComposerItem
     /**Is emitted when the map has been prepared for atlas rendering, just before actual rendering*/
     void preparedForAtlas();
 
+    /** Emitted when layer style overrides are changed... a means to let
+     * associated legend items know they should update
+     * @note added in 2.10
+     */
+    void layerStyleOverridesChanged();
+
   public slots:
 
     /**Forces an update of the cached map image*/

src/core/layertree/qgslayertreemodel.cpp

@@ -24,6 +24,7 @@
 #include "qgsdataitem.h"
 #include "qgsmaphittest.h"
 #include "qgsmaplayerlegend.h"
+#include "qgsmaplayerstylemanager.h"
 #include "qgspluginlayer.h"
 #include "qgsrasterlayer.h"
 #include "qgsrendererv2.h"
@@ -602,6 +603,16 @@ void QgsLayerTreeModel::legendMapViewData( double* mapUnitsPerPixel, int* dpi, d
   if ( scale ) *scale = mLegendMapViewScale;
 }
 
+QMap<QString, QString> QgsLayerTreeModel::layerStyleOverrides() const
+{
+  return mLayerStyleOverrides;
+}
+
+void QgsLayerTreeModel::setLayerStyleOverrides( const QMap<QString, QString>& overrides )
+{
+  mLayerStyleOverrides = overrides;
+}
+
 void QgsLayerTreeModel::nodeWillAddChildren( QgsLayerTreeNode* node, int indexFrom, int indexTo )
 {
   Q_ASSERT( node );
@@ -1064,10 +1075,15 @@ void QgsLayerTreeModel::addLegendToLayer( QgsLayerTreeLayer* nodeL )
   if ( !nodeL->layer() )
     return;
 
-  QgsMapLayerLegend* layerLegend = nodeL->layer()->legend();
+  QgsMapLayer* ml = nodeL->layer();
+  QgsMapLayerLegend* layerLegend = ml->legend();
   if ( !layerLegend )
     return;
 
+  bool hasStyleOverride = mLayerStyleOverrides.contains( ml->id() );
+  if ( hasStyleOverride )
+    ml->styleManager()->setOverrideStyle( mLayerStyleOverrides.value( ml->id() ) );
+
   QList<QgsLayerTreeModelLegendNode*> lstNew = layerLegend->createLayerTreeModelLegendNodes( nodeL );
 
   // apply filtering defined in layer node's custom properties (reordering, filtering, custom labels)
@@ -1099,6 +1115,9 @@ void QgsLayerTreeModel::addLegendToLayer( QgsLayerTreeLayer* nodeL )
   mLegend[nodeL] = data;
 
   if ( ! isEmbedded ) endInsertRows();
+
+  if ( hasStyleOverride )
+    ml->styleManager()->restoreOverrideStyle();
 }
 
 

src/core/layertree/qgslayertreemodel.h

@@ -164,6 +164,13 @@ class CORE_EXPORT QgsLayerTreeModel : public QAbstractItemModel
     //! @note added in 2.6
     void legendMapViewData( double *mapUnitsPerPixel, int *dpi, double *scale );
 
+    //! Get map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one
+    //! @note added in 2.10
+    QMap<QString, QString> layerStyleOverrides() const;
+    //! Set map of map layer style overrides (key: layer ID, value: style name) where a different style should be used instead of the current one
+    //! @note added in 2.10
+    void setLayerStyleOverrides( const QMap<QString, QString>& overrides );
+
     //! Return true if index represents a legend node (instead of layer node)
     //! @deprecated use index2legendNode()
     Q_DECL_DEPRECATED bool isIndexSymbologyNode( const QModelIndex& index ) const;
@@ -269,6 +276,10 @@ class CORE_EXPORT QgsLayerTreeModel : public QAbstractItemModel
 
     void tryBuildLegendTree( LayerLegendData& data );
 
+    //! Overrides of map layers' styles: key = layer ID, value = style XML.
+    //! This allows to show legend that is different from the current style of layers
+    QMap<QString, QString> mLayerStyleOverrides;
+
     //! Per layer data about layer's legend nodes
     QMap<QgsLayerTreeLayer*, LayerLegendData> mLegend;
 

src/core/qgsmaplayerstylemanager.cpp

@@ -166,6 +166,7 @@ bool QgsMapLayerStyleManager::setOverrideStyle( const QString& styleDef )
   if ( mOverriddenOriginalStyle )
     return false; // cannot override the style more than once!
 
+  mLayer->blockSignals( true );
   if ( mStyles.contains( styleDef ) )
   {
     mOverriddenOriginalStyle = new QgsMapLayerStyle;
@@ -183,16 +184,20 @@ bool QgsMapLayerStyleManager::setOverrideStyle( const QString& styleDef )
     QgsMapLayerStyle overrideStyle( styleDef );
     overrideStyle.writeToLayer( mLayer );
   }
+  mLayer->blockSignals( false );
 
-  return false;
+  return true;
 }
 
 bool QgsMapLayerStyleManager::restoreOverrideStyle()
 {
   if ( !mOverriddenOriginalStyle )
     return false;
 
+  mLayer->blockSignals( true );
   mOverriddenOriginalStyle->writeToLayer( mLayer );
+  mLayer->blockSignals( false );
+
   delete mOverriddenOriginalStyle;
   mOverriddenOriginalStyle = 0;
   return true;