bool DeleteArrowHead(int position, const wxString& name);
bool DeleteLineControlPoint();
void DrawArrows(wxDC& dc);
void DrawRegion(wxDC& dc, wxShapeRegion *region, double x, double y);
void EraseRegion(wxDC& dc, wxShapeRegion *region, double x, double y);
bool DeleteArrowHead(int position, const wxString& name);
bool DeleteLineControlPoint();
void DrawArrows(wxDC& dc);
void DrawRegion(wxDC& dc, wxShapeRegion *region, double x, double y);
void EraseRegion(wxDC& dc, wxShapeRegion *region, double x, double y);