[vertex tool] Respect topo editing when adding a vertex (fixes #18046)

wonder-sk · nyalldawson · commit 9f5664a593ba · 2018-11-06T10:49:34.000+10:00
When adding a vertex to a segment that is coincident with some other segments and topological editing is enabled, vertex tool will now correctly add new vertex also the coincident segments to preserve shared borders. (cherry picked from commit 5dd5664)
diff --git a/src/app/vertextool/qgsvertextool.cpp b/src/app/vertextool/qgsvertextool.cpp
@@ -1372,6 +1372,26 @@ QList<QgsPointLocator::Match> QgsVertexTool::layerVerticesSnappedToPoint( QgsVec
   return myfilter.matches;
 }
 
+QList<QgsPointLocator::Match> QgsVertexTool::layerSegmentsSnappedToSegment( QgsVectorLayer *layer, const QgsPointXY &mapPoint1, const QgsPointXY &mapPoint2 )
+{
+  QList<QgsPointLocator::Match> finalMatches;
+  // we want segment matches that have exactly the same vertices as the given segment (mapPoint1, mapPoint2)
+  // so rather than doing nearest edge search which could return any segment within a tolerance,
+  // we first find matches for one endpoint and then see if there is a matching other endpoint.
+  const QList<QgsPointLocator::Match> matches1 = layerVerticesSnappedToPoint( layer, mapPoint1 );
+  for ( const QgsPointLocator::Match &m : matches1 )
+  {
+    QgsGeometry g = cachedGeometry( layer, m.featureId() );
+    int v0, v1;
+    g.adjacentVertices( m.vertexIndex(), v0, v1 );
+    if ( v0 != -1 && QgsPointXY( g.vertexAt( v0 ) ) == mapPoint2 )
+      finalMatches << QgsPointLocator::Match( QgsPointLocator::Edge, layer, m.featureId(), 0, m.point(), v0 );
+    else if ( v1 != -1 && QgsPointXY( g.vertexAt( v1 ) ) == mapPoint2 )
+      finalMatches << QgsPointLocator::Match( QgsPointLocator::Edge, layer, m.featureId(), 0, m.point(), m.vertexIndex() );
+  }
+  return finalMatches;
+}
+
 void QgsVertexTool::startDraggingAddVertex( const QgsPointLocator::Match &m )
 {
   Q_ASSERT( m.hasEdge() );
@@ -1383,6 +1403,7 @@ void QgsVertexTool::startDraggingAddVertex( const QgsPointLocator::Match &m )
   mDraggingVertexType = AddingVertex;
   mDraggingExtraVertices.clear();
   mDraggingExtraVerticesOffset.clear();
+  mDraggingExtraSegments.clear();
 
   QgsGeometry geom = cachedGeometry( m.layer(), m.featureId() );
 
@@ -1398,6 +1419,36 @@ void QgsVertexTool::startDraggingAddVertex( const QgsPointLocator::Match &m )
   if ( v1.x() != 0 || v1.y() != 0 )
     addDragBand( map_v1, m.point() );
 
+  if ( QgsProject::instance()->topologicalEditing() )
+  {
+    // find other segments coincident with the one user just picked and store them in a list
+    // so we can add a new vertex also in those to keep topology correct
+    const auto layers = canvas()->layers();
+    for ( QgsMapLayer *layer : layers )
+    {
+      QgsVectorLayer *vlayer = qobject_cast<QgsVectorLayer *>( layer );
+      if ( !vlayer || !vlayer->isEditable() )
+        continue;
+
+      if ( vlayer->geometryType() != QgsWkbTypes::LineGeometry && vlayer->geometryType() != QgsWkbTypes::PolygonGeometry )
+        continue;
+
+      QgsPointXY pt1, pt2;
+      m.edgePoints( pt1, pt2 );
+      const auto snappedSegments = layerSegmentsSnappedToSegment( vlayer, pt1, pt2 );
+      for ( const QgsPointLocator::Match &otherMatch : snappedSegments )
+      {
+        if ( otherMatch.layer() == m.layer() &&
+             otherMatch.featureId() == m.featureId() &&
+             otherMatch.vertexIndex() == m.vertexIndex() )
+          continue;
+
+        // start dragging of snapped point of current layer
+        mDraggingExtraSegments << Vertex( otherMatch.layer(), otherMatch.featureId(), otherMatch.vertexIndex() );
+      }
+    }
+  }
+
   cadDockWidget()->setPoints( QList<QgsPointXY>() << m.point() << m.point() );
 }
 
@@ -1563,6 +1614,13 @@ void QgsVertexTool::moveVertex( const QgsPointXY &mapPoint, const QgsPointLocato
 
   addExtraVerticesToEdits( edits, mapPoint, dragLayer, layerPoint );
 
+  if ( addingVertex && !addingAtEndpoint && QgsProject::instance()->topologicalEditing() )
+  {
+    // topo editing: when adding a vertex to an existing segment, there may be other coincident segments
+    // that also need adding the same vertex
+    addExtraSegmentsToEdits( edits, mapPoint, dragLayer, layerPoint );
+  }
+
   applyEditsToLayers( edits );
 
   if ( QgsProject::instance()->topologicalEditing() && mapPointMatch->hasEdge() && mapPointMatch->layer() )
@@ -1625,6 +1683,40 @@ void QgsVertexTool::addExtraVerticesToEdits( QgsVertexTool::VertexEdits &edits,
 }
 
 
+void QgsVertexTool::addExtraSegmentsToEdits( QgsVertexTool::VertexEdits &edits, const QgsPointXY &mapPoint, QgsVectorLayer *dragLayer, const QgsPointXY &layerPoint )
+{
+  // insert new vertex also to other geometries/layers
+  for ( int i = 0; i < mDraggingExtraSegments.count(); ++i )
+  {
+    const Vertex &topo = mDraggingExtraSegments[i];
+
+    QHash<QgsFeatureId, QgsGeometry> &layerEdits = edits[topo.layer];
+    QgsGeometry topoGeom;
+    if ( layerEdits.contains( topo.fid ) )
+      topoGeom = QgsGeometry( edits[topo.layer][topo.fid] );
+    else
+      topoGeom = QgsGeometry( cachedGeometryForVertex( topo ) );
+
+    QgsPointXY point;
+    if ( dragLayer && topo.layer->crs() == dragLayer->crs() )
+      point = layerPoint;  // this point may come from exact match so it may be more precise
+    else
+      point = toLayerCoordinates( topo.layer, mapPoint );
+
+    QgsPoint pt( point );
+    if ( QgsWkbTypes::hasZ( topo.layer->wkbType() ) )
+      pt.addZValue( defaultZValue() );
+
+    if ( !topoGeom.insertVertex( pt, topo.vertexId + 1 ) )
+    {
+      QgsDebugMsg( QStringLiteral( "[topo] segment insert vertex failed!" ) );
+      continue;
+    }
+    edits[topo.layer][topo.fid] = topoGeom;
+  }
+}
+
+
 void QgsVertexTool::applyEditsToLayers( QgsVertexTool::VertexEdits &edits )
 {
   QHash<QgsVectorLayer *, QHash<QgsFeatureId, QgsGeometry> >::iterator it = edits.begin();
diff --git a/src/app/vertextool/qgsvertextool.h b/src/app/vertextool/qgsvertextool.h
@@ -156,6 +156,9 @@ class APP_EXPORT QgsVertexTool : public QgsMapToolAdvancedDigitizing
     //! Gets list of matches of all vertices of a layer exactly snapped to a map point
     QList<QgsPointLocator::Match> layerVerticesSnappedToPoint( QgsVectorLayer *layer, const QgsPointXY &mapPoint );
 
+    //! Gets list of matches of all segments of a layer coincident with the given segment
+    QList<QgsPointLocator::Match> layerSegmentsSnappedToSegment( QgsVectorLayer *layer, const QgsPointXY &mapPoint1, const QgsPointXY &mapPoint2 );
+
     void startDraggingAddVertex( const QgsPointLocator::Match &m );
 
     void startDraggingAddVertexAtEndpoint( const QgsPointXY &mapPoint );
@@ -177,6 +180,8 @@ class APP_EXPORT QgsVertexTool : public QgsMapToolAdvancedDigitizing
 
     void addExtraVerticesToEdits( VertexEdits &edits, const QgsPointXY &mapPoint, QgsVectorLayer *dragLayer = nullptr, const QgsPointXY &layerPoint = QgsPointXY() );
 
+    void addExtraSegmentsToEdits( QgsVertexTool::VertexEdits &edits, const QgsPointXY &mapPoint, QgsVectorLayer *dragLayer, const QgsPointXY &layerPoint );
+
     void applyEditsToLayers( VertexEdits &edits );
 
 
@@ -330,6 +335,12 @@ class APP_EXPORT QgsVertexTool : public QgsMapToolAdvancedDigitizing
      */
     QList<QgsVector> mDraggingExtraVerticesOffset;
 
+    /**
+     * list of Vertex instances identifying segments (by their first vertex index) that should
+     * also get a new vertex: this is used for topo editing when adding a vertex to existing segment
+     */
+    QList<Vertex> mDraggingExtraSegments;
+
     // members for selection handling
 
     //! list of Vertex instances of vertices that are selected
diff --git a/tests/src/app/testqgsvertextool.cpp b/tests/src/app/testqgsvertextool.cpp
@@ -64,6 +64,7 @@ class TestQgsVertexTool : public QObject
     void testMoveMultipleVertices();
     void testMoveVertexTopo();
     void testDeleteVertexTopo();
+    void testAddVertexTopo();
     void testActiveLayerPriority();
     void testSelectedFeaturesPriority();
 
@@ -532,6 +533,37 @@ void TestQgsVertexTool::testDeleteVertexTopo()
   QgsProject::instance()->setTopologicalEditing( false );
 }
 
+void TestQgsVertexTool::testAddVertexTopo()
+{
+  // test addition of a vertex on a segment shared with another geometry
+
+  // add a temporary polygon
+  QgsFeature fTmp;
+  fTmp.setGeometry( QgsGeometry::fromWkt( "POLYGON((4 4, 7 4, 7 6, 4 6, 4 4))" ) );
+  bool resAdd = mLayerPolygon->addFeature( fTmp );
+  QVERIFY( resAdd );
+  QgsFeatureId fTmpId = fTmp.id();
+
+  QCOMPARE( mLayerPolygon->undoStack()->index(), 2 );
+
+  QgsProject::instance()->setTopologicalEditing( true );
+
+  mouseClick( 5.5, 4, Qt::LeftButton );
+  mouseClick( 5, 5, Qt::LeftButton );
+
+  QCOMPARE( mLayerPolygon->undoStack()->index(), 3 );
+
+  QCOMPARE( mLayerPolygon->getFeature( mFidPolygonF1 ).geometry(), QgsGeometry::fromWkt( "POLYGON((4 1, 7 1, 7 4, 5 5, 4 4, 4 1))" ) );
+  QCOMPARE( mLayerPolygon->getFeature( fTmpId ).geometry(), QgsGeometry::fromWkt( "POLYGON((4 4, 5 5, 7 4, 7 6, 4 6, 4 4))" ) );
+
+  mLayerPolygon->undoStack()->undo();
+  mLayerPolygon->undoStack()->undo();
+
+  QCOMPARE( mLayerPolygon->getFeature( mFidPolygonF1 ).geometry(), QgsGeometry::fromWkt( "POLYGON((4 1, 7 1, 7 4, 4 4, 4 1))" ) );
+
+  QgsProject::instance()->setTopologicalEditing( false );
+}
+
 void TestQgsVertexTool::testActiveLayerPriority()
 {
   // check that features from current layer get priority when picking points
