Implement node selecting and deleting

Author: Miguel Ferreira

src/FlowGraphicsView.cpp

@@ -109,6 +109,44 @@ wheelEvent(QWheelEvent *event)
   scale(factor, factor);
 }
 
+void
+FlowGraphicsView::
+keyPressEvent(QKeyEvent *event)
+{
+	switch (event->key())
+	{
+	case Qt::Key_Escape:
+		_scene->clearSelection();
+		break;
+	case Qt::Key_Delete:
+		foreach(QGraphicsItem* item, _scene->selectedItems()){
+			_scene->removeNode(item);
+		}
+		break;
+	case Qt::Key_Shift:
+		setDragMode(QGraphicsView::RubberBandDrag);
+		break;
+	default:
+		break;
+	}
+	QGraphicsView::keyPressEvent(event);
+}
+
+void
+FlowGraphicsView::
+keyReleaseEvent(QKeyEvent *event)
+{
+	switch (event->key())
+	{
+	case Qt::Key_Shift:
+		setDragMode(QGraphicsView::ScrollHandDrag);
+		break;
+	default:
+		break;
+	}
+	QGraphicsView::keyReleaseEvent(event);
+}
+
 
 void
 FlowGraphicsView::

src/FlowGraphicsView.hpp

@@ -19,6 +19,10 @@ class NODE_EDITOR_PUBLIC FlowGraphicsView
 
   void wheelEvent(QWheelEvent *event) override;
 
+  void keyPressEvent(QKeyEvent *event) override;
+
+  void keyReleaseEvent(QKeyEvent *event) override;
+
   void drawBackground(QPainter* painter, const QRectF& r) override;
 
 private:

src/FlowScene.cpp

@@ -57,6 +57,26 @@ createNode(std::unique_ptr<NodeDataModel> && dataModel)
   return node;
 }
 
+void
+FlowScene::
+removeNode(QGraphicsItem* item)
+{
+	auto ngo = dynamic_cast<NodeGraphicsObject*>(item);
+	std::shared_ptr<Node> const& node = ngo->node().lock();
+
+	auto nodeState = node->nodeState();
+	for (std::weak_ptr<Connection> conn : nodeState.getEntries(PortType::In)) {
+		if(!conn.expired())
+			this->deleteConnection(conn.lock());
+	}
+	for (std::weak_ptr<Connection> conn : nodeState.getEntries(PortType::Out)) {
+		if (!conn.expired())
+			this->deleteConnection(conn.lock());
+	}
+
+	_nodes.erase(node->id());
+}
+
 
 FlowScene::
 FlowScene()

src/FlowScene.hpp

@@ -49,6 +49,9 @@ class NODE_EDITOR_PUBLIC FlowScene
   std::shared_ptr<Node>
   createNode(std::unique_ptr<NodeDataModel> &&dataModel);
 
+  void
+  removeNode(QGraphicsItem* item);
+
 private:
 
   using SharedConnection = std::shared_ptr<Connection>;

src/NodeGraphicsObject.cpp

@@ -28,6 +28,9 @@ NodeGraphicsObject(FlowScene &scene,
   setFlag(QGraphicsItem::ItemDoesntPropagateOpacityToChildren, true);
   setFlag(QGraphicsItem::ItemIsMovable, true);
   setFlag(QGraphicsItem::ItemIsFocusable, true);
+  setFlag(QGraphicsItem::ItemIsSelectable, true);
+  setFlag(QGraphicsItem::ItemSendsScenePositionChanges);
+
 
   setCacheMode( QGraphicsItem::DeviceCoordinateCache );
 
@@ -166,11 +169,24 @@ paint(QPainter * painter,
   NodePainter::paint(painter, node);
 }
 
+QVariant
+NodeGraphicsObject::
+itemChange(GraphicsItemChange change, const QVariant &value) {
+	if (change == ItemPositionChange && scene()) {
+		moveConnections();
+	}
+	return QGraphicsItem::itemChange(change, value);
+}
 
 void
 NodeGraphicsObject::
 mousePressEvent(QGraphicsSceneMouseEvent * event)
 {
+
+  if (!this->isSelected() && !(event->modifiers() & Qt::ControlModifier)) {
+		_scene.clearSelection();
+  }
+
   auto clickPort =
   [&](PortType portToCheck)
   {
@@ -216,11 +232,7 @@ mousePressEvent(QGraphicsSceneMouseEvent * event)
 
   clickPort(PortType::In);
   clickPort(PortType::Out);
-
-  event->accept();
-
-//------
-
+  
   auto pos     = event->pos();
   auto node    = _node.lock();
   auto & geom  = node->nodeGeometry();

src/NodeGraphicsObject.hpp

@@ -46,6 +46,9 @@ class NodeGraphicsObject : public QGraphicsObject
         QStyleOptionGraphicsItem const* option,
         QWidget*                        widget = 0) override;
 
+  QVariant
+  itemChange(GraphicsItemChange change, const QVariant &value) override;
+
   void
   mousePressEvent(QGraphicsSceneMouseEvent* event) override;
 

src/NodePainter.cpp

@@ -2,6 +2,7 @@
 
 #include <QtCore/QMargins>
 
+#include "NodeGraphicsObject.hpp"
 #include "NodeGeometry.hpp"
 #include "NodeState.hpp"
 #include "NodeDataModel.hpp"
@@ -16,11 +17,13 @@ paint(QPainter* painter,
 
   NodeState const& state = node->nodeState();
 
+  std::unique_ptr<NodeGraphicsObject> const& graphicsObject = node->nodeGraphicsObject();
+
   geom.recalculateSize(painter->fontMetrics());
 
   //--------------------------------------------
 
-  drawNodeRect(painter, geom);
+  drawNodeRect(painter, geom, graphicsObject);
 
   drawConnectionPoints(painter, geom, state);
 
@@ -39,16 +42,19 @@ paint(QPainter* painter,
 void
 NodePainter::
 drawNodeRect(QPainter* painter,
-             NodeGeometry const& geom)
+             NodeGeometry const& geom,
+             std::unique_ptr<NodeGraphicsObject> const& graphicsObject)
 {
+  auto color = graphicsObject->isSelected() ? QColor(255, 150, 0) : Qt::white;
+
   if (geom.hovered())
   {
-    QPen p(Qt::white, 2.0);
+    QPen p(color, 2.0);
     painter->setPen(p);
   }
   else
   {
-    QPen p(Qt::white, 1.5);
+    QPen p(color, 1.5);
     painter->setPen(p);
   }
 

src/NodePainter.hpp

@@ -6,6 +6,7 @@
 
 #include "PortType.hpp"
 
+class NodeGraphicsObject;
 class NodeGeometry;
 class NodeState;
 class Node;
@@ -27,7 +28,8 @@ class NodePainter
 
   static
   void
-  drawNodeRect(QPainter* painter, NodeGeometry const& geom);
+  drawNodeRect(QPainter* painter, NodeGeometry const& geom,
+               std::unique_ptr<NodeGraphicsObject> const& graphicsObject);
 
   static
   void