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

#ifndef GRAPH_DISPLAYER_CANVAS_H

#define GRAPH_DISPLAYER_CANVAS_H

#include <all_include.h>

#include <mapstorage.h>

#include <libgnomecanvasmm.h>

#include <libgnomecanvasmm/polygon.h>

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

class GraphDisplayerCanvas : public Gnome::Canvas::CanvasAA

{

  typedef Gnome::Canvas::CanvasAA Parent;

public:

  GraphDisplayerCanvas(Graph &, CoordinatesMap &, MapStorage &);

  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 changeLineWidth (std::string mapname);

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

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

  int changeColor (std::string mapname);

  ///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 changeText (std::string mapname);

  ///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

  bool event_handler(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 move_event_handler(GdkEvent*);

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

  bool create_node_event_handler(GdkEvent*);

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

  bool create_edge_event_handler(GdkEvent*);

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

  bool eraser_event_handler(GdkEvent*);

  ///Deletes the given element.

  void delete_item(NodeIt);

  ///Deletes the given element.

  void delete_item(EdgeIt);

  ///The graph, on which we work

  Graph g;

  ///Map of nodes of graph

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

  ///Map of edges of graph

  Graph::EdgeMap<Gnome::Canvas::Line *> edgesmap;

  ///Map of texts to write on edges

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

  ///Group of graphical elements of displayed_graph

  Gnome::Canvas::Group displayed_graph;

  ///Here we store the maps that can be displayed through properties.

  MapStorage mapstorage;

  ///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;

  ///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;

  Graph::NodeIt active_node;

  Graph::EdgeIt active_edge;

  static const int zoom_step = 5;

};

#endif //GRAPH_DISPLAYER_CANVAS_H