Fix add ring/fill ring tool works on first polygon (fix #13069)

Now the tools will prefer to operate on selected features first.
Improves editing of overlapping features.

python/core/qgsvectorlayereditutils.sip

@@ -28,6 +28,8 @@ class QgsVectorLayerEditUtils
     /** Adds a ring to polygon/multipolygon features
      * @param ring ring to add
      * @param featureId if specified, feature ID for feature ring was added to will be stored in this parameter
+     * @param preferredFeatureIds if specified, the features will be the first candidates for adding a ring. Otherwise
+     * all intersecting features are tested and the ring is added to the first valid feature.
      @return
        0 in case of success,
        1 problem with feature type,

src/core/qgsvectorlayer.cpp

@@ -1064,7 +1064,7 @@ int QgsVectorLayer::addRing( const QList<QgsPoint>& ring, QgsFeatureId* featureI
     return 6;
 
   QgsVectorLayerEditUtils utils( this );
-  return utils.addRing( ring, featureId );
+  return utils.addRing( ring, featureId, mSelectedFeatureIds );
 }
 
 int QgsVectorLayer::addRing( QgsCurveV2* ring, QgsFeatureId* featureId )
@@ -1087,7 +1087,7 @@ int QgsVectorLayer::addRing( QgsCurveV2* ring, QgsFeatureId* featureId )
   }
 
   QgsVectorLayerEditUtils utils( this );
-  return utils.addRing( ring, featureId );
+  return utils.addRing( ring, featureId, mSelectedFeatureIds );
 }
 
 int QgsVectorLayer::addPart( const QList<QgsPoint> &points )

src/core/qgsvectorlayereditutils.cpp

@@ -104,7 +104,7 @@ bool QgsVectorLayerEditUtils::deleteVertex( QgsFeatureId atFeatureId, int atVert
   return true;
 }
 
-int QgsVectorLayerEditUtils::addRing( const QList<QgsPoint>& ring, QgsFeatureId* featureId )
+int QgsVectorLayerEditUtils::addRing( const QList<QgsPoint>& ring, QgsFeatureId* featureId, const QgsFeatureIds& preferredFeatureIds )
 {
   QgsLineStringV2* ringLine = new QgsLineStringV2();
   QList< QgsPointV2 > ringPoints;
@@ -114,10 +114,10 @@ int QgsVectorLayerEditUtils::addRing( const QList<QgsPoint>& ring, QgsFeatureId*
     ringPoints.append( QgsPointV2( ringIt->x(), ringIt->y() ) );
   }
   ringLine->setPoints( ringPoints );
-  return addRing( ringLine, featureId );
+  return addRing( ringLine, featureId, preferredFeatureIds );
 }
 
-int QgsVectorLayerEditUtils::addRing( QgsCurveV2* ring, QgsFeatureId* featureId )
+int QgsVectorLayerEditUtils::addRing( QgsCurveV2* ring, QgsFeatureId* modifiedFeatureId, const QgsFeatureIds& preferredFeatureIds )
 {
   if ( !L->hasGeometryType() )
   {
@@ -126,22 +126,45 @@ int QgsVectorLayerEditUtils::addRing( QgsCurveV2* ring, QgsFeatureId* featureId
   }
 
   int addRingReturnCode = 5; //default: return code for 'ring not inserted'
-  QgsRectangle bBox = ring->boundingBox();
-  QgsFeatureIterator fit = L->getFeatures( QgsFeatureRequest().setFilterRect( bBox ).setFlags( QgsFeatureRequest::ExactIntersect ) );
-
   QgsFeature f;
-  while ( fit.nextFeature( f ) )
-  {
-    //add ring takes ownership of ring, and deletes it if there's an error
-    addRingReturnCode = f.geometry()->addRing( static_cast< QgsCurveV2* >( ring->clone() ) );
-    if ( addRingReturnCode == 0 )
-    {
-      L->editBuffer()->changeGeometry( f.id(), f.geometry() );
-      if ( featureId )
-        *featureId = f.id();
 
-      //setModified( true, true );
+  //see if part can be added to preferred features
-      break;
+  if ( !preferredFeatureIds.isEmpty() )
+  {
+    QgsFeatureIterator fit = L->getFeatures( QgsFeatureRequest().setFilterFids( preferredFeatureIds ) );
+    while ( fit.nextFeature( f ) )
+    {
+      //add ring takes ownership of ring, and deletes it if there's an error
+      addRingReturnCode = f.geometry()->addRing( static_cast< QgsCurveV2* >( ring->clone() ) );
+      if ( addRingReturnCode == 0 )
+      {
+        L->editBuffer()->changeGeometry( f.id(), f.geometry() );
+        if ( modifiedFeatureId )
+          *modifiedFeatureId = f.id();
+
+        break;
+      }
+    }
+  }
+
+  //no match so far, so check other intersecting features
+  if ( addRingReturnCode != 0 )
+  {
+    QgsRectangle bBox = ring->boundingBox();
+    QgsFeatureIterator fit = L->getFeatures( QgsFeatureRequest().setFilterRect( bBox ).setFlags( QgsFeatureRequest::ExactIntersect ) );
+    while ( fit.nextFeature( f ) )
+    {
+      //add ring takes ownership of ring, and deletes it if there's an error
+      addRingReturnCode = f.geometry()->addRing( static_cast< QgsCurveV2* >( ring->clone() ) );
+      if ( addRingReturnCode == 0 )
+      {
+        L->editBuffer()->changeGeometry( f.id(), f.geometry() );
+        if ( modifiedFeatureId )
+          *modifiedFeatureId = f.id();
+
+        //setModified( true, true );
+        break;
+      }
     }
   }
 

src/core/qgsvectorlayereditutils.h

@@ -56,6 +56,8 @@ class CORE_EXPORT QgsVectorLayerEditUtils
     /** Adds a ring to polygon/multipolygon features
      * @param ring ring to add
      * @param featureId if specified, feature ID for feature ring was added to will be stored in this parameter
+     * @param preferredFeatureIds if specified, the features will be the first candidates for adding a ring. Otherwise
+     * all intersecting features are tested and the ring is added to the first valid feature.
      @return
        0 in case of success,
        1 problem with feature type,
@@ -63,11 +65,13 @@ class CORE_EXPORT QgsVectorLayerEditUtils
        3 ring not valid,
        4 ring crosses existing rings,
        5 no feature found where ring can be inserted*/
-    int addRing( const QList<QgsPoint>& ring, QgsFeatureId* featureId = 0 );
+    int addRing( const QList<QgsPoint>& ring, QgsFeatureId* featureId = 0, const QgsFeatureIds& preferredFeatureIds = QgsFeatureIds() );
 
     /** Adds a ring to polygon/multipolygon features
      * @param ring ring to add
      * @param featureId if specified, feature ID for feature ring was added to will be stored in this parameter
+     * @param preferredFeatureIds if specified, the features will be the first candidates for adding a ring. Otherwise
+     * all intersecting features are tested and the ring is added to the first valid feature.
          @return
            0 in case of success,
            1 problem with feature type,
@@ -75,7 +79,7 @@ class CORE_EXPORT QgsVectorLayerEditUtils
            3 ring not valid,
            4 ring crosses existing rings,
            5 no feature found where ring can be inserted*/
-    int addRing( QgsCurveV2* ring, QgsFeatureId* featureId = 0 );
+    int addRing( QgsCurveV2* ring, QgsFeatureId* modifiedFeatureId = 0, const QgsFeatureIds& preferredFeatureIds = QgsFeatureIds() );
 
     /** Adds a new part polygon to a multipart feature
      @return