nodeview: support multiple flow directions

app/widget/nodeview/nodeviewitem.h

@@ -28,6 +28,7 @@
 #include <QWidget>
 
 #include "node/node.h"
+#include "nodeviewcommon.h"
 #include "nodeviewedge.h"
 #include "nodeviewitemwidgetproxy.h"
 
@@ -71,6 +72,19 @@ public:
    */
   QPointF GetParamPoint(NodeParam* param) const;
 
+  /**
+   * @brief Sets the direction nodes are flowing
+   */
+  void SetFlowDirection(NodeViewCommon::FlowDirection dir);
+
+  static int DefaultTextPadding();
+
+  static int DefaultItemHeight();
+
+  static int DefaultItemWidth();
+
+  static int DefaultItemBorder();
+
 protected:
   virtual void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = nullptr) override;
 
@@ -153,6 +167,8 @@ private:
    */
   QUndoCommand* node_edge_change_command_;
 
+  NodeViewCommon::FlowDirection flow_dir_;
+
 };
 
 OLIVE_NAMESPACE_EXIT