Fix GitHub Issue #25: Add a way to delete edges

- Right-click on edge opens context menu with a delete option

CHANGELOG

@@ -1,3 +1,11 @@
+x.y.z
+=====
+
+New features:
+
+* Fix GitHub Issue #25: Add a way to delete edges
+  * Right-click on edge opens context menu with a delete option
+
 1.8.0 - "Mighty Move"
 =====================
 

src/constants.hpp

@@ -138,6 +138,8 @@ static const int MAX_SIZE = 24;
 
 namespace View {
 
+static const int CLICK_TOLERANCE = 5;
+
 static const double DRAG_NODE_OPACITY = 0.5;
 
 static const int ZOOM_MAX = 200;

src/editor_data.cpp

@@ -55,6 +55,8 @@ void EditorData::loadMindMapData(QString fileName)
 {
     clearSelectionGroup();
 
+    m_selectedEdge = nullptr;
+
     m_selectedNode = nullptr;
 
 #ifndef HEIMER_UNIT_TEST
@@ -82,6 +84,8 @@ void EditorData::undo()
     {
         clearSelectionGroup();
 
+        m_selectedEdge = nullptr;
+
         m_selectedNode = nullptr;
 
         m_dragAndDropNode = nullptr;
@@ -105,6 +109,8 @@ void EditorData::redo()
 {
     if (m_undoStack.isRedoable())
     {
+        m_selectedEdge = nullptr;
+
         m_selectedNode = nullptr;
 
         m_dragAndDropNode = nullptr;
@@ -190,6 +196,20 @@ EdgePtr EditorData::addEdge(EdgePtr edge)
     return edge;
 }
 
+void EditorData::deleteEdge(Edge & edge)
+{
+    assert(m_mindMapData);
+
+    m_mindMapData->graph().deleteEdge(edge.sourceNode().index(), edge.targetNode().index());
+}
+
+void EditorData::deleteNode(Node & node)
+{
+    assert(m_mindMapData);
+
+    m_mindMapData->graph().deleteNode(node.index());
+}
+
 NodePtr EditorData::addNodeAt(QPointF pos)
 {
     assert(m_mindMapData);
@@ -243,11 +263,21 @@ void EditorData::moveSelectionGroup(Node & reference, QPointF location)
     }
 }
 
+void EditorData::setSelectedEdge(Edge * edge)
+{
+    m_selectedEdge = edge;
+}
+
 void EditorData::setSelectedNode(Node * node)
 {
     m_selectedNode = node;
 }
 
+Edge * EditorData::selectedEdge() const
+{
+    return m_selectedEdge;
+}
+
 Node * EditorData::selectedNode() const
 {
     return m_selectedNode;

src/editor_data.hpp

@@ -46,6 +46,10 @@ class EditorData : public QObject
 
     EdgePtr addEdge(EdgePtr edge);
 
+    void deleteEdge(Edge & edge);
+
+    void deleteNode(Node & node);
+
     NodePtr addNodeAt(QPointF pos);
 
     void clearSelectionGroup();
@@ -82,8 +86,12 @@ class EditorData : public QObject
 
     void setMindMapData(MindMapDataPtr newMindMapData);
 
+    void setSelectedEdge(Edge * edge);
+
     void setSelectedNode(Node * node);
 
+    Edge * selectedEdge() const;
+
     Node * selectedNode() const;
 
     size_t selectionGroupSize() const;
@@ -117,6 +125,8 @@ class EditorData : public QObject
 
     UndoStack m_undoStack;
 
+    Edge * m_selectedEdge = nullptr;
+
     Node * m_selectedNode = nullptr;
 
     std::set<Node *> m_selectionGroup;

src/editor_view.cpp

@@ -46,6 +46,7 @@ EditorView::EditorView(Mediator & mediator)
     : m_mediator(mediator)
 {
     createBackgroundContextMenuActions();
+    createEdgeContextMenuActions();
     createNodeContextMenuActions();
 
     setHorizontalScrollBarPolicy(Qt::ScrollBarAlwaysOff);
@@ -83,6 +84,19 @@ void EditorView::createBackgroundContextMenuActions()
     m_backgroundContextMenu.addAction(createNode);
 }
 
+void EditorView::createEdgeContextMenuActions()
+{
+    m_deleteEdgeAction = new QAction(tr("Delete edge"), &m_edgeContextMenu);
+    QObject::connect(m_deleteEdgeAction, &QAction::triggered, [=] {
+        assert(m_mediator.selectedEdge());
+        m_mediator.saveUndoPoint();
+        m_mediator.deleteEdge(*m_mediator.selectedEdge());
+    });
+
+    // Populate the menu
+    m_edgeContextMenu.addAction(m_deleteEdgeAction);
+}
+
 void EditorView::createNodeContextMenuActions()
 {
     m_setNodeColorAction = new QAction(tr("Set node color"), &m_nodeContextMenu);
@@ -139,6 +153,14 @@ void EditorView::handleMousePressEventOnBackground(QMouseEvent & event)
     }
 }
 
+void EditorView::handleMousePressEventOnEdge(QMouseEvent & event, Edge & edge)
+{
+    if (event.button() == Qt::RightButton)
+    {
+        handleRightButtonClickOnEdge(edge);
+    }
+}
+
 void EditorView::handleMousePressEventOnNode(QMouseEvent & event, Node & node)
 {
     if (node.index() != -1) // Prevent right-click on the drag node
@@ -209,6 +231,13 @@ void EditorView::handleLeftButtonClickOnNodeHandle(NodeHandle & nodeHandle)
     }
 }
 
+void EditorView::handleRightButtonClickOnEdge(Edge & edge)
+{
+    m_mediator.setSelectedEdge(&edge);
+
+    openEdgeContextMenu();
+}
+
 void EditorView::handleRightButtonClickOnNode(Node & node)
 {
     m_mediator.setSelectedNode(&node);
@@ -287,9 +316,11 @@ void EditorView::mousePressEvent(QMouseEvent * event)
     m_clickedPos = event->pos();
     m_clickedScenePos = mapToScene(m_clickedPos);
 
+    const int tolerance = Constants::View::CLICK_TOLERANCE;
+    QRectF clickRect(m_clickedScenePos.x() - tolerance, m_clickedScenePos.y() - tolerance, tolerance * 2, tolerance * 2);
+
     // Fetch all items at the location
-    QList<QGraphicsItem *> items = scene()->items(
-        m_clickedScenePos, Qt::IntersectsItemShape, Qt::DescendingOrder);
+    QList<QGraphicsItem *> items = scene()->items(clickRect, Qt::IntersectsItemShape, Qt::DescendingOrder);
 
     if (items.size())
     {
@@ -298,6 +329,10 @@ void EditorView::mousePressEvent(QMouseEvent * event)
         {
             handleMousePressEventOnNode(*event, *node);
         }
+        else if (auto edge = dynamic_cast<Edge *>(item))
+        {
+            handleMousePressEventOnEdge(*event, *edge);
+        }
         else if (auto node = dynamic_cast<NodeHandle *>(item))
         {
             handleMousePressEventOnNodeHandle(*event, *node);
@@ -356,6 +391,11 @@ void EditorView::openBackgroundContextMenu()
     m_backgroundContextMenu.exec(mapToGlobal(m_clickedPos));
 }
 
+void EditorView::openEdgeContextMenu()
+{
+    m_edgeContextMenu.exec(mapToGlobal(m_clickedPos));
+}
+
 void EditorView::openNodeContextMenu()
 {
     // Allow deletion of leaf nodes or nodes between exactly two nodes.

src/editor_view.hpp

@@ -81,10 +81,14 @@ public slots:
 
     void createBackgroundContextMenuActions();
 
+    void createEdgeContextMenuActions();
+
     void createNodeContextMenuActions();
 
     void handleMousePressEventOnBackground(QMouseEvent & event);
 
+    void handleMousePressEventOnEdge(QMouseEvent & event, Edge & edge);
+
     void handleMousePressEventOnNode(QMouseEvent & event, Node & node);
 
     void handleMousePressEventOnNodeHandle(QMouseEvent & event, NodeHandle & nodeHandle);
@@ -93,6 +97,8 @@ public slots:
 
     void handleLeftButtonClickOnNodeHandle(NodeHandle & nodeHandle);
 
+    void handleRightButtonClickOnEdge(Edge & edge);
+
     void handleRightButtonClickOnNode(Node & node);
 
     void initiateNewNodeDrag(NodeHandle & nodeHandle);
@@ -101,6 +107,8 @@ public slots:
 
     void openBackgroundContextMenu();
 
+    void openEdgeContextMenu();
+
     void openNodeContextMenu();
 
     void removeNodeFromSelectionGroup(Node & node);
@@ -115,6 +123,8 @@ public slots:
 
     QMenu m_backgroundContextMenu;
 
+    QMenu m_edgeContextMenu;
+
     QMenu m_nodeContextMenu;
 
     QPoint m_clickedPos;
@@ -131,6 +141,8 @@ public slots:
 
     QAction * m_setNodeTextColorAction = nullptr;
 
+    QAction * m_deleteEdgeAction = nullptr;
+
     QAction * m_deleteNodeAction = nullptr;
 
     QAction * m_deleteRow = nullptr;

src/graph.cpp

@@ -48,6 +48,24 @@ void Graph::addNode(NodeBasePtr node)
     m_nodes.push_back(node);
 }
 
+void Graph::deleteEdge(int index0, int index1)
+{
+    EdgeVector::iterator edgeIter;
+    bool edgeErased = false;
+    do
+    {
+        edgeIter = std::find_if(
+            m_edges.begin(), m_edges.end(), [=] (const EdgeBasePtr & edge){
+                return edge->sourceNodeBase().index() == index0 && edge->targetNodeBase().index() == index1;
+            });
+        edgeErased = edgeIter != m_edges.end();
+        if (edgeErased)
+        {
+            m_edges.erase(edgeIter);
+        }
+    } while (edgeErased);
+}
+
 void Graph::deleteNode(int index)
 {
     const auto iter = std::find_if(m_nodes.begin(), m_nodes.end(), [=] (const NodeBasePtr & node) {

src/graph.hpp

@@ -48,6 +48,8 @@ class Graph
 
     void addEdge(EdgeBasePtr edge);
 
+    void deleteEdge(int index0, int index1);
+
     bool areDirectlyConnected(NodeBasePtr node0, NodeBasePtr node1);
 
     //! Warning: this should not be used outside unit tests as it creates a pure EdgeBase

src/mediator.cpp

@@ -167,10 +167,15 @@ DragAndDropStore & Mediator::dadStore()
     return m_editorData->dadStore();
 }
 
+void Mediator::deleteEdge(Edge & edge)
+{
+    m_editorData->deleteEdge(edge);
+}
+
 void Mediator::deleteNode(Node & node)
 {
     m_editorView->resetDummyDragItems();
-    m_editorData->mindMapData()->graph().deleteNode(node.index());
+    m_editorData->deleteNode(node);
 }
 
 void Mediator::enableUndo(bool enable)
@@ -359,6 +364,11 @@ QSize Mediator::sceneRectSize() const
     return m_editorScene->sceneRect().size().toSize();
 }
 
+Edge * Mediator::selectedEdge() const
+{
+    return m_editorData->selectedEdge();
+}
+
 Node * Mediator::selectedNode() const
 {
     return m_editorData->selectedNode();
@@ -425,6 +435,11 @@ void Mediator::setEditorView(EditorView & editorView)
     });
 }
 
+void Mediator::setSelectedEdge(Edge * edge)
+{
+    m_editorData->setSelectedEdge(edge);
+}
+
 void Mediator::setSelectedNode(Node * node)
 {
     m_editorData->setSelectedNode(node);

src/mediator.hpp

@@ -68,6 +68,8 @@ class Mediator : public QObject
 
     DragAndDropStore & dadStore();
 
+    void deleteEdge(Edge & edge);
+
     void deleteNode(Node & node);
 
     QString fileName() const;
@@ -108,6 +110,8 @@ class Mediator : public QObject
 
     QSize sceneRectSize() const;
 
+    Edge * selectedEdge() const;
+
     Node * selectedNode() const;
 
     size_t selectionGroupSize() const;
@@ -118,6 +122,8 @@ class Mediator : public QObject
 
     void setEditorView(EditorView & editorView);
 
+    void setSelectedEdge(Edge * edge);
+
     void setSelectedNode(Node * node);
 
     void setupMindMapAfterUndoOrRedo();