// -*- C++ -*- //

 #ifndef GRAPH_DISPLAYER_CANVAS_H

 #define GRAPH_DISPLAYER_CANVAS_H

 class GraphDisplayerCanvas;

 #include "all_include.h"

 #include "nbtab.h"

 #include <libgnomecanvasmm.h>

 #include <libgnomecanvasmm/polygon.h>

 #include <lemon/xy.h>

 ///This class is the canvas, on which the graph can be drawn.

 class GraphDisplayerCanvas : public Gnome::Canvas::CanvasAA

 {

   class BrokenEdge : public Gnome::Canvas::Line

   {

     GraphDisplayerCanvas & gdc;

     Gnome::Canvas::Polygon * arrow;

     Gnome::Art::Point * my_points;

     ///Indicates whether the button of mouse is pressed or not

     bool isbutton;

     ///At this location was the mousebutton pressed.

     ///It helps to calculate the distance of dragging.

     double clicked_x, clicked_y;

     ///event handler for forming edges

     bool edgeFormerEventHandler(GdkEvent*);

   public:

     BrokenEdge(Gnome::Canvas::Group &, Gnome::Canvas::Points, GraphDisplayerCanvas &);

     ~BrokenEdge();

     void setPoints(Gnome::Canvas::Points, bool move=false);

     xy<double> getArrowPos();

   };

   typedef Gnome::Canvas::CanvasAA Parent;

 public:

   GraphDisplayerCanvas(NoteBookTab &);

   virtual ~GraphDisplayerCanvas();

   ///Changes the linewidth attribute according to the given map.

   ///\param mapname is the name of the map which contains the new values

   int changeEdgeWidth (std::string mapname, Edge new_item=INVALID);

   int resetEdgeWidth (Edge new_item=INVALID);

   ///Changes the linecolor attribute according to the given map.

   ///\param mapname is the name of the map which contains the new values

   int changeEdgeColor (std::string mapname, Edge new_item=INVALID);

   int resetEdgeColor (Edge new_item=INVALID);

   ///Changes the text of line attribute according to the given map.

   ///\param mapname is the name of the map which contains the new values

   int changeEdgeText (std::string mapname, Edge new_item=INVALID);

   int resetEdgeText (Edge new_item=INVALID);

   ///Changes the linewidth attribute according to the given map.

   ///\param mapname is the name of the map which contains the new values

   int changeNodeRadius (std::string mapname, Node new_item=INVALID);

   int resetNodeRadius (Node new_item=INVALID);

   ///Changes the linecolor attribute according to the given map.

   ///\param mapname is the name of the map which contains the new values

   int changeNodeColor (std::string mapname, Node new_item=INVALID);

   int resetNodeColor (Node new_item=INVALID);

   ///Changes the text of line attribute according to the given map.

   ///\param mapname is the name of the map which contains the new values

   int changeNodeText (std::string mapname, Node new_item=INVALID);

   int resetNodeText (Node new_item=INVALID);

   void propertyChange(bool, int);

   void propertyUpdate(Edge, int, int dummy=0);

   void propertyUpdate(Node, int, int dummy=0);

   void propertyUpdate(Edge);

   void propertyUpdate(Node);

   ///Callback for 'ViewZoomIn' action.

   virtual void zoomIn();

   ///Callback for 'ViewZoomOut' action.

   virtual void zoomOut();

   ///Callback for 'ViewZoomFit' action.

   virtual void zoomFit();

   ///Callback for 'ViewZoom100' action.

   virtual void zoom100();

   ///Sets the scroll region of the convas to the bounding box of the graph.

   void updateScrollRegion();

   ///This function changes the tool in the graph-editor's hand

   void changeEditorialTool(int);

 protected:

   //maximizing, minimizing, restoring window, etc. 

   virtual bool on_expose_event(GdkEventExpose *);

 private:

   ///This function is responsible for the correct

   ///reaction of any action happened in the territory

   ///of the canvas

   ///DEPRECATED!!!!

   bool eventHandler(GdkEvent* e, Node n);

   ///actual event handler

   ///

   ///Actual event handler should be stored, to be able to disconnect it and later reconnect it.

   sigc::connection actual_handler;

   ///event handler for the case when move-tool is active

   bool moveEventHandler(GdkEvent*);

   ///event handler for the case when create_node-tool is active

   bool createNodeEventHandler(GdkEvent*);

   ///event handler for the case when create_edge-tool is active

   bool createEdgeEventHandler(GdkEvent*);

   ///event handler for the case when eraser-tool is active

   bool eraserEventHandler(GdkEvent*);

   ///event handler for the case when edge map editor tool is active

   bool edgeMapEditEventHandler(GdkEvent*);

   ///event handler for the case when node map editor tool is active

   bool nodeMapEditEventHandler(GdkEvent*);

 public:

   ///Moves the text to new place

   void textReposition(xy<double>);

   ///Activates an edge belonging to a BrokenEdge

   ///

   ///After we have activated an edge this way,

   ///the GDC object will know, which edge is under forming

   ///therefore it can redraw the necessarz elementy on the canvas,

   ///for example the text belonging to the \ref BrokenEdge can be

   ///redrawn (\ref textReposition).

   void toggleEdgeActivity(BrokenEdge*, bool);

 public:

   ///\return the actual tool in hand

   int getActualTool();

   void drawGraph();

   void clear();

   ///creates a new Nodemap

   int addNewNodeMap(double,std::string);

   ///creates a new Edgemap

   int addNewEdgeMap(double,std::string);

 private:

   ///Deletes the given element.

   void deleteItem(Node);

   ///Deletes the given element.

   void deleteItem(Edge);

 private:

   ///Map of nodes of graph

   Graph::NodeMap<Gnome::Canvas::Ellipse *> nodesmap;

   ///Map of edges of graph

   Graph::EdgeMap<BrokenEdge *> edgesmap;

   ///Map of texts to write on edges

   Graph::EdgeMap<Gnome::Canvas::Text *> edgetextmap;

   ///Map of texts to write on nodes

   Graph::NodeMap<Gnome::Canvas::Text *> nodetextmap;

   ///Group of graphical elements of displayed_graph

   Gnome::Canvas::Group displayed_graph;

 private:

   ///Indicates whether the button of mouse is pressed or not

   int isbutton;

   ///Stores the actual tool in hand

   int actual_tool;

   ///At this location was the mousebutton pressed.

   ///It helps to calculate the distance of dragging.

   double clicked_x, clicked_y;

   ///Remembers which Gnome::Canvas::Item was pressed.

   ///this variable is needed, because

   ///1. we cannot query the item at he cursor as fast as it could not cause a Segmentation Fault

   ///2. we would like to handle only ony item per movement, therefore quering it is not a working solution

   Gnome::Canvas::Item * active_item, * target_item;

   Node active_node;

   Edge active_edge;

   Edge forming_edge;

   std::string nodemap_to_edit, edgemap_to_edit;

   static const int zoom_step = 5;

 private:

   ///reference to the parent window

   NoteBookTab & mytab;

 };

 #endif //GRAPH_DISPLAYER_CANVAS_H