feat: connect nodes

src/gui/network/SocketGraphic.h

@@ -6,16 +6,24 @@ class SocketGraphic
 : public QGraphicsItem
 {
 public:
-    SocketGraphic(QGraphicsItem *parent = nullptr);
     QRectF boundingRect() const override;
 
     void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget) override;
 
+    enum class SocketType {
+        Input,
+        Output
+    };
+
+    SocketGraphic(SocketGraphic::SocketType type, QGraphicsItem *parent = nullptr);
+    SocketType getIO();
+
 private:
     int socketSize_ = 1;
     QBrush brushInactive_;
     QBrush brushActive_;
     bool hovered_=false;
+    SocketType type_;
 protected:
     void hoverEnterEvent(QGraphicsSceneHoverEvent *event) override;
     void hoverLeaveEvent(QGraphicsSceneHoverEvent *event) override;