If there are selected features, the split tool is only applies to the selection. Added a warning for users in case they may have forgotten that a selection exists (or for users that don't know this feature

git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@9480 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: mhugent

src/app/qgsmaptoolsplitfeatures.cpp

@@ -80,7 +80,11 @@ void QgsMapToolSplitFeatures::canvasReleaseEvent( QMouseEvent * e )
     //bring up dialog if a split was not possible (polygon) or only done once (line)
     int topologicalEditing = QgsProject::instance()->readNumEntry( "Digitizing", "/TopologicalEditing", 0 );
     int returnCode = vlayer->splitFeatures( mCaptureList, topologicalEditing );
-    if ( returnCode != 0 )
+    if(returnCode == 4)
+      {
+	QMessageBox::warning(0, tr("No feature split done"), tr("If there are selected features, the split tool only applies to the selected ones. If you like to split all features under the split line, clear the selection"));
+      }
+    else if ( returnCode != 0 )
     {
       //several intersections but only one split (most likely line)
       QMessageBox::warning( 0, tr( "Split error" ), tr( "An error occured during feature splitting" ) );

src/core/qgsvectorlayer.cpp

@@ -1672,6 +1672,7 @@ int QgsVectorLayer::splitFeatures( const QList<QgsPoint>& splitLine, bool topolo
   QgsRect bBox; //bounding box of the split line
   int returnCode = 0;
   int splitFunctionReturn; //return code of QgsGeometry::splitGeometry
+  int numberOfSplitedFeatures = 0;
 
   QgsFeatureList featureList;
   const QgsFeatureIds selectedIds = selectedFeaturesIds();
@@ -1749,13 +1750,22 @@ int QgsVectorLayer::splitFeatures( const QList<QgsPoint>& splitLine, bool topolo
           addTopologicalPoints( *topol_it );
         }
       }
+      ++numberOfSplitedFeatures;
     }
     else if ( splitFunctionReturn > 1 ) //1 means no split but also no error
     {
       returnCode = 3;
     }
   }
 
+  if(numberOfSplitedFeatures == 0 && selectedIds.size() > 0)
+    {
+      //There is a selection but no feature has been split.
+      //Maybe user forgot that only the selected features are split
+      returnCode = 4;
+    }
+
+
   //now add the new features to this vectorlayer
   addFeatures( newFeatures, false );
 

src/core/qgsvectorlayer.h

@@ -287,7 +287,7 @@ class CORE_EXPORT QgsVectorLayer : public QgsMapLayer
     /**Splits features cut by the given line
        @param splitLine line that splits the layer features
        @param topologicalEditing true if topological editing is enabled
-       @return 0 in case of success*/
+       @return 0 in case of success, 4 if there is a selection but no feature split*/
     int splitFeatures( const QList<QgsPoint>& splitLine, bool topologicalEditing = false );
 
     /**Changes the specified geometry such that it has no intersections with other