change symbols for selected ranges using changeBtn; retains colors

Author: Arunmozhi

src/gui/symbology-ng/qgsgraduatedsymbolrendererv2widget.cpp

@@ -239,7 +239,16 @@ void QgsGraduatedSymbolRendererV2Widget::reapplyColorRamp()
 
 void QgsGraduatedSymbolRendererV2Widget::changeGraduatedSymbol()
 {
+  // Change the selected symbols alone if anything is selected
+  QItemSelectionModel* m = viewGraduated->selectionModel();
+  QModelIndexList i = m->selectedRows();
+  if ( m && i.size() > 0 )
+  {
+    changeSelectedSymbols();
+    return;
+  }
 
+  // Otherwise change the base mGraduatedSymbol
   QgsSymbolV2* newSymbol = mGraduatedSymbol->clone();
 
   QgsSymbolV2SelectorDialog dlg( newSymbol, mStyle, mLayer, this );
@@ -328,6 +337,34 @@ void QgsGraduatedSymbolRendererV2Widget::rangesClicked( const QModelIndex & idx
     mRowSelected = idx.row();
 }
 
+void QgsGraduatedSymbolRendererV2Widget::changeSelectedSymbols()
+{
+  QItemSelectionModel* m = viewGraduated->selectionModel();
+  QModelIndexList selectedIndexes = m->selectedRows( 1 );
+  if ( m && selectedIndexes.size() > 0 )
+  {
+    QgsSymbolV2* newSymbol = mGraduatedSymbol->clone();
+    QgsSymbolV2SelectorDialog dlg( newSymbol, mStyle, mLayer, this );
+    if ( !dlg.exec() )
+    {
+      delete newSymbol;
+      return;
+    }
+
+    foreach( QModelIndex idx, selectedIndexes )
+    {
+      if( idx.isValid() )
+      {
+        int rangeIdx = idx.row();
+        QgsSymbolV2* newRangeSymbol = newSymbol->clone();
+        newRangeSymbol->setColor( mRenderer->ranges()[rangeIdx].symbol()->color() );
+        mRenderer->updateRangeSymbol( rangeIdx, newRangeSymbol );
+      }
+    }
+  }
+  refreshSymbolView();
+}
+
 void QgsGraduatedSymbolRendererV2Widget::changeRangeSymbol( int rangeIdx )
 {
   QgsSymbolV2* newSymbol = mRenderer->ranges()[rangeIdx].symbol()->clone();

src/gui/symbology-ng/qgsgraduatedsymbolrendererv2widget.h

@@ -68,6 +68,8 @@ class GUI_EXPORT QgsGraduatedSymbolRendererV2Widget : public QgsRendererV2Widget
     void changeRangeSymbol( int rangeIdx );
     void changeRange( int rangeIdx );
 
+    void changeSelectedSymbols();
+
     QList<QgsSymbolV2*> selectedSymbols();
     QgsSymbolV2* findSymbolForRange( double lowerBound, double upperBound, const QgsRangeList& ranges ) const;
     void refreshSymbolView();