small cleanups, itemAt fix with Map

lib/qtgraph/edge.cpp

@@ -8,12 +8,13 @@
 static const double Pi = 3.14159265358979323846264338327950288419717;
 static double TwoPi = 2.0 * Pi;
 
-Edge::Edge(Node *sourceNode, Node *destNode)
+Edge::Edge(Node* s, Node* d, Edge::ArrowStyle arrowStyle  )
-    : arrowSize(10)
+    : m_arrowStyle(arrowStyle)
+    , arrowSize(10)
 {
     setAcceptedMouseButtons(0);
-    source = sourceNode;
+    source = s;
-    dest = destNode;
+    dest = d;
     source->addEdge(this);
     dest->addEdge(this);
     adjust();
@@ -67,7 +68,7 @@ void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
     if (!source || !dest)
         return;
 
-    QLineF line(sourcePoint, destPoint);
+    const QLineF line(sourcePoint, destPoint);
     if (qFuzzyCompare(line.length(), qreal(0.)))
         return;
 
@@ -76,20 +77,24 @@ void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
     painter->drawLine(line);
 
     // Draw the arrows
+    if (m_arrowStyle == NoArrow)
+      return;
+
     double angle = ::acos(line.dx() / line.length());
     if (line.dy() >= 0)
         angle = TwoPi - angle;
 
-    QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + Pi / 3) * arrowSize,
-                                                  cos(angle + Pi / 3) * arrowSize);
-    QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + Pi - Pi / 3) * arrowSize,
-                                                  cos(angle + Pi - Pi / 3) * arrowSize);
-    QPointF destArrowP1 = destPoint + QPointF(sin(angle - Pi / 3) * arrowSize,
-                                              cos(angle - Pi / 3) * arrowSize);
-    QPointF destArrowP2 = destPoint + QPointF(sin(angle - Pi + Pi / 3) * arrowSize,
-                                              cos(angle - Pi + Pi / 3) * arrowSize);
-
     painter->setBrush(Qt::black);
+
+    if (m_arrowStyle == ArrowToSource || m_arrowStyle == ArrowToBothSides) {
+      const QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + Pi / 3) * arrowSize, cos(angle + Pi / 3) * arrowSize);
+      const QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + Pi - Pi / 3) * arrowSize, cos(angle + Pi - Pi / 3) * arrowSize);
       painter->drawPolygon(QPolygonF() << line.p1() << sourceArrowP1 << sourceArrowP2);
+    }
+
+    if (m_arrowStyle == ArrowToDestination || m_arrowStyle == ArrowToBothSides) {
+      const QPointF destArrowP1 = destPoint + QPointF(sin(angle - Pi / 3) * arrowSize, cos(angle - Pi / 3) * arrowSize);
+      const QPointF destArrowP2 = destPoint + QPointF(sin(angle - Pi + Pi / 3) * arrowSize, cos(angle - Pi + Pi / 3) * arrowSize);
       painter->drawPolygon(QPolygonF() << line.p2() << destArrowP1 << destArrowP2);
     }
+}

lib/qtgraph/edge.hpp

@@ -8,7 +8,15 @@ class Node;
 class Edge : public QGraphicsItem
 {
 public:
-    Edge(Node *sourceNode, Node *destNode);
+
+    enum ArrowStyle {
+      NoArrow,
+      ArrowToDestination,
+      ArrowToSource,
+      ArrowToBothSides
+    };
+
+    Edge(Node *source, Node *destination, ArrowStyle arrowStyle = NoArrow );
 
     Node *sourceNode() const;
     Node *destNode() const;
@@ -24,6 +32,7 @@ protected:
 
 private:
     Node *source, *dest;
+    ArrowStyle m_arrowStyle;
 
     QPointF sourcePoint;
     QPointF destPoint;

lib/qtgraph/graphwidget.cpp

@@ -12,10 +12,6 @@
 
 #include <QtGui/QApplication>
 
-#include <QtCore/QtGlobal>
-
-#include <math.h>
-
 namespace std {
   template <>
   struct hash<float2>
@@ -28,6 +24,11 @@ namespace std {
   };
 }
 
+// for the map
+bool operator< (const float2& v1, const float2& v2) {
+  return length(v1) < length(v2);
+}
+
 
 GraphWidget::GraphWidget(Graph<float2>* graph, QWidget *p)
     : QGraphicsView(p)
@@ -56,25 +57,19 @@ void GraphWidget::itemMoved(const QPointF oldPos, const QPointF newPos)
 
 void GraphWidget::updateFromGraph()
 {
-//   for (const auto cit : m_graph) {
+  // scene()->itemAt returns the topmost only which can be an Edge
+  QMap<float2, Node*> node_map;
   for (Graph<float2>::iterator cit = m_graph->begin(); cit != m_graph->end(); ++cit) {
     Node *node = new Node(this);
     scene()->addItem(node);
     node->setPos(cit->x, cit->y);
+    node_map.insert(*cit, node);
   }
 
-//     for (const auto cit : g) {
   for (Graph<float2>::iterator cit = m_graph->begin(); cit != m_graph->end(); ++cit) {
     for (const auto cit2 : m_graph->neighboursOf(*cit)) {
-
+      Node* node1 = node_map.find(*cit).value();
-      float2 v = *cit;
+      Node* node2 = node_map.find(cit2).value();
-      Node* node1 = dynamic_cast<Node*>(scene()->itemAt(v.x, v.y)); /// @bug itemAt sometimes doesn't work
-      Q_CHECK_PTR(node1);
-
-      float2 v2 = cit2;
-      Node* node2 = dynamic_cast<Node*>(scene()->itemAt(v2.x, v2.y)); /// @bug itemAt sometimes doesn't work
-      Q_CHECK_PTR(node2);
-
       scene()->addItem(new Edge(node1, node2));
     }
   }

lib/qtgraph/main.cpp

@@ -27,19 +27,19 @@ namespace std {
   };
 
   template <typename T>
-  std::string to_string_with_precision(const T a_value, const int n = 6)
+  inline std::string to_string_with_precision(const T a_value, const int n = 6)
   {
       std::ostringstream out;
       out << std::fixed << std::setprecision(n) << a_value;
       return out.str();
   }
-}
 
-// inline std::ostream& operator<< (std::ostream& os, const float2& f2)
+  inline std::ostream& operator<< (std::ostream& os, const float2& f2)
-// {
+  {
-//   os << f2.x << "," << f2.y;
+    os << std::to_string_with_precision(f2);
-//   return os;
+    return os;
-// }
+  }
+}
 
 float2 float2creator(const std::string& line)
 {
@@ -61,7 +61,8 @@ int main(int argc, char **argv)
   qsrand(QTime(0,0,0).secsTo(QTime::currentTime()));
 
 
-  Graph<float2> g = readGraphFromXML<float2>("graph_example.xml", float2creator);
+  const std::string xml_file = "graph_example.xml";
+  Graph<float2> g = readGraphFromXML<float2>(xml_file, float2creator);
 
   GraphWidget *widget = new GraphWidget(&g);
   widget->updateFromGraph();
@@ -77,6 +78,6 @@ int main(int argc, char **argv)
   mainWindow.show();
   const int app_retval = app.exec();
 
-  writeGraphToXML<float2>(g, "graph_example.xml", float2serializer);
+  writeGraphToXML<float2>(g, xml_file, float2serializer);
   return app_retval;
 }