Node tool: give priority to the current layer when selecting vertex

wonder-sk · wonder-sk · commit 31b6b5885fdb · 2017-09-08T15:12:50.000+02:00
diff --git a/src/app/nodetool/qgsnodetool.cpp b/src/app/nodetool/qgsnodetool.cpp
@@ -596,6 +596,10 @@ void QgsNodeTool::removeTemporaryRubberBands()
 
 QgsPointLocator::Match QgsNodeTool::snapToEditableLayer( QgsMapMouseEvent *e )
 {
+  QgsSnappingUtils *snapUtils = canvas()->snappingUtils();
+  QgsSnappingConfig oldConfig = snapUtils->config();
+  QgsPointLocator::Match m;
+
   QgsPointXY mapPoint = toMapCoordinates( e->pos() );
   double tol = QgsTolerance::vertexSearchRadius( canvas()->mapSettings() );
 
@@ -604,21 +608,44 @@ QgsPointLocator::Match QgsNodeTool::snapToEditableLayer( QgsMapMouseEvent *e )
   config.setMode( QgsSnappingConfig::AdvancedConfiguration );
   config.setIntersectionSnapping( false );  // only snap to layers
 
-  Q_FOREACH ( QgsMapLayer *layer, canvas()->layers() )
+  // if there is a current layer, it should have priority over other layers
+  // because sometimes there may be match from multiple layers at one location
+  // and selecting current layer is an easy way for the user to prioritize a layer
+  if ( QgsVectorLayer *currentVlayer = currentVectorLayer() )
   {
-    QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( layer );
-    if ( !vlayer )
-      continue;
+    if ( currentVlayer->isEditable() )
+    {
+      Q_FOREACH ( QgsMapLayer *layer, canvas()->layers() )
+      {
+        QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( layer );
+        if ( !vlayer )
+          continue;
+
+        config.setIndividualLayerSettings( vlayer, QgsSnappingConfig::IndividualLayerSettings(
+                                             vlayer == currentVlayer, QgsSnappingConfig::VertexAndSegment, tol, QgsTolerance::ProjectUnits ) );
+      }
 
-    config.setIndividualLayerSettings( vlayer, QgsSnappingConfig::IndividualLayerSettings(
-                                         vlayer->isEditable(), QgsSnappingConfig::VertexAndSegment, tol, QgsTolerance::ProjectUnits ) );
+      snapUtils->setConfig( config );
+      m = snapUtils->snapToMap( mapPoint );
+    }
   }
 
-  QgsSnappingUtils *snapUtils = canvas()->snappingUtils();
-  QgsSnappingConfig oldConfig = snapUtils->config();
-  snapUtils->setConfig( config );
+  // if there is no match from the current layer, try to use any editable vector layer
+  if ( !m.isValid() )
+  {
+    Q_FOREACH ( QgsMapLayer *layer, canvas()->layers() )
+    {
+      QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( layer );
+      if ( !vlayer )
+        continue;
 
-  QgsPointLocator::Match m = snapUtils->snapToMap( mapPoint );
+      config.setIndividualLayerSettings( vlayer, QgsSnappingConfig::IndividualLayerSettings(
+                                           vlayer->isEditable(), QgsSnappingConfig::VertexAndSegment, tol, QgsTolerance::ProjectUnits ) );
+    }
+
+    snapUtils->setConfig( config );
+    m = snapUtils->snapToMap( mapPoint );
+  }
 
   // try to stay snapped to previously used feature
   // so the highlight does not jump around at nodes where features are joined
diff --git a/tests/src/app/testqgsnodetool.cpp b/tests/src/app/testqgsnodetool.cpp
@@ -63,6 +63,7 @@ class TestQgsNodeTool : public QObject
     void testMoveMultipleVertices();
     void testMoveVertexTopo();
     void testDeleteVertexTopo();
+    void testActiveLayerPriority();
 
   private:
     QPoint mapToScreen( double mapX, double mapY )
@@ -532,5 +533,50 @@ void TestQgsNodeTool::testDeleteVertexTopo()
   QgsProject::instance()->setTopologicalEditing( false );
 }
 
+void TestQgsNodeTool::testActiveLayerPriority()
+{
+  // check that features from current layer get priority when picking points
+
+  // create a temporary line layer that has a common vertex with existing line layer at (1, 1)
+  QgsVectorLayer *layerLine2 = new QgsVectorLayer( "LineString?crs=EPSG:27700", "layer line 2", "memory" );
+  QVERIFY( layerLine2->isValid() );
+  QgsPolyline line1;
+  line1 << QgsPointXY( 0, 1 ) << QgsPointXY( 1, 1 ) << QgsPointXY( 1, 0 );
+  QgsFeature lineF1;
+  lineF1.setGeometry( QgsGeometry::fromPolyline( line1 ) );
+  layerLine2->startEditing();
+  layerLine2->addFeature( lineF1 );
+  QgsFeatureId fidLineF1 = lineF1.id();
+  QCOMPARE( layerLine2->featureCount(), ( long )1 );
+  QgsProject::instance()->addMapLayer( layerLine2 );
+  mCanvas->setLayers( QList<QgsMapLayer *>() << mLayerLine << mLayerPolygon << mLayerPoint << layerLine2 );
+
+  // make one layer active and check its vertex is used
+
+  mCanvas->setCurrentLayer( mLayerLine );
+
+  mouseClick( 1, 1, Qt::LeftButton );
+  mouseClick( 0, 0, Qt::LeftButton );
+
+  QCOMPARE( mLayerLine->getFeature( mFidLineF1 ).geometry(), QgsGeometry::fromWkt( "LINESTRING(2 1, 0 0, 1 3)" ) );
+  QCOMPARE( layerLine2->getFeature( fidLineF1 ).geometry(), QgsGeometry::fromWkt( "LINESTRING(0 1, 1 1, 1 0)" ) );
+  mLayerLine->undoStack()->undo();
+
+  // make the other layer active and check its vertex is used
+
+  mCanvas->setCurrentLayer( layerLine2 );
+
+  mouseClick( 1, 1, Qt::LeftButton );
+  mouseClick( 0, 0, Qt::LeftButton );
+
+  QCOMPARE( mLayerLine->getFeature( mFidLineF1 ).geometry(), QgsGeometry::fromWkt( "LINESTRING(2 1, 1 1, 1 3)" ) );
+  QCOMPARE( layerLine2->getFeature( fidLineF1 ).geometry(), QgsGeometry::fromWkt( "LINESTRING(0 1, 0 0, 1 0)" ) );
+  layerLine2->undoStack()->undo();
+
+  // get rid of the temporary layer
+  mCanvas->setLayers( QList<QgsMapLayer *>() << mLayerLine << mLayerPolygon << mLayerPoint );
+  QgsProject::instance()->removeMapLayer( layerLine2 );
+}
+
 QGSTEST_MAIN( TestQgsNodeTool )
 #include "testqgsnodetool.moc"
