Added possibility to delete features for OGR layers.

However then I've found out that nearly no OGR drivers support it :-)


git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@5062 c8812cc2-4d05-0410-92ff-de0c093fc19c

Author: wonder

src/providers/ogr/qgsogrprovider.cpp

@@ -1159,6 +1159,25 @@ bool QgsOgrProvider::createSpatialIndex()
     }
 }
 
+bool QgsOgrProvider::deleteFeatures(std::list<int> const & id)
+{
+  bool returnvalue=true;
+  for(std::list<int>::const_iterator it=id.begin();it!=id.end();++it)
+  {
+    if(!deleteFeature(*it))
+    {
+      returnvalue=false;
+    }
+  }
+  return returnvalue;
+}
+
+bool QgsOgrProvider::deleteFeature(int id)
+{
+  OGRErr res = ogrLayer->DeleteFeature(id);
+  return (res == OGRERR_NONE);
+}
+
 int QgsOgrProvider::capabilities() const
 {
   int ability = NoCapabilities;
@@ -1185,6 +1204,12 @@ int QgsOgrProvider::capabilities() const
       ability |= QgsVectorDataProvider::AddFeatures;
     }
 
+    if (ogrLayer->TestCapability("DeleteFeature"))
+    // TRUE if this layer can delete its features
+    {
+      ability |= DeleteFeatures;
+    }
+
     if (ogrLayer->TestCapability("RandomWrite"))
     // TRUE if the SetFeature() method is operational on this layer.
     {
@@ -1232,9 +1257,10 @@ int QgsOgrProvider::capabilities() const
     {
       // No use required for this QGIS release.
     }
-
+    
 #ifdef QGISDEBUG
-  std::cout << "QgsOgrProvider::capabilities: GDAL Version Num is 'GDAL_VERSION_NUM'." << std::endl;
+  std::cout << "QgsOgrProvider::capabilities: GDAL Version Num is '" <<
+    GDAL_VERSION_NUM << "'." << std::endl;
 #endif
 
     if (1)

src/providers/ogr/qgsogrprovider.h

@@ -147,6 +147,9 @@ class QgsOgrProvider:public QgsVectorDataProvider
     /**Writes a list of features to the file*/
     bool addFeatures(std::list<QgsFeature*> const flist);
 
+    /**Deletes a feature*/
+    bool deleteFeatures(std::list<int> const & id);
+    
     /**Adds new attributess. Unfortunately not supported for layers with features in it*/
     bool addAttributes(std::map<QString,QString> const & name);
 
@@ -260,6 +263,8 @@ class QgsOgrProvider:public QgsVectorDataProvider
     OGRPolygon * mSelectionRectangle;
     /**Adds one feature*/
     bool addFeature(QgsFeature* f);
+    /**Deletes one feature*/
+    bool deleteFeature(int id);
     //! The geometry factory
     geos::GeometryFactory *geometryFactory;
     //! The well known text reader