nodeview: implemented ability to select and delete node edges

app/widget/nodeview/nodeviewedge.cpp

@@ -23,6 +23,7 @@
 #include <QApplication>
 #include <QDebug>
 #include <QGraphicsSceneMouseEvent>
+#include <QStyleOptionGraphicsItem>
 
 #include "common/clamp.h"
 #include "common/lerp.h"
@@ -34,10 +35,12 @@ OLIVE_NAMESPACE_ENTER
 NodeViewEdge::NodeViewEdge(QGraphicsItem *parent) :
   QGraphicsPathItem(parent),
   edge_(nullptr),
-  color_group_(QPalette::Active),
-  color_role_(QPalette::Text),
+  connected_(false),
+  highlighted_(false),
   flow_dir_(NodeViewCommon::kLeftToRight)
 {
+  setFlag(QGraphicsItem::ItemIsSelectable);
+
   // Ensures this UI object is drawn behind other objects
   setZValue(-1);
 
@@ -83,24 +86,16 @@ void NodeViewEdge::Adjust()
 
 void NodeViewEdge::SetConnected(bool c)
 {
-  if (c) {
-    color_group_ = QPalette::Active;
-  } else {
-    color_group_ = QPalette::Disabled;
-  }
+  connected_ = c;
 
-  UpdatePen();
+  update();
 }
 
 void NodeViewEdge::SetHighlighted(bool e)
 {
-  if (e) {
-    color_role_ = QPalette::Highlight;
-  } else {
-    color_role_ = QPalette::Text;
-  }
+  highlighted_ = e;
 
-  UpdatePen();
+  update();
 }
 
 void NodeViewEdge::SetPoints(const QPointF &start, const QPointF &end, bool input_is_expanded)
@@ -137,9 +132,26 @@ void NodeViewEdge::SetFlowDirection(NodeViewCommon::FlowDirection dir)
   Adjust();
 }
 
-void NodeViewEdge::UpdatePen()
+void NodeViewEdge::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *)
 {
-  setPen(QPen(qApp->palette().color(color_group_, color_role_), edge_width_));
+  QPalette::ColorGroup group;
+  QPalette::ColorRole role;
+
+  if (connected_) {
+    group = QPalette::Active;
+  } else {
+    group = QPalette::Disabled;
+  }
+
+  if (highlighted_ != bool(option->state & QStyle::State_Selected)) {
+    role = QPalette::Highlight;
+  } else {
+    role = QPalette::Text;
+  }
+
+  painter->setPen(QPen(qApp->palette().color(group, role), edge_width_));
+  painter->setBrush(Qt::NoBrush);
+  painter->drawPath(path());
 }
 
 OLIVE_NAMESPACE_EXIT