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livetrax/libs/canvas/canvas/arrow.h

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2.2 KiB
C++

/*
Copyright (C) 2011 Paul Davis
Author: Carl Hetherington <cth@carlh.net>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/** @file canvas/arrow.h
* @brief Declaration of the Arrow canvas object.
*/
#ifndef __CANVAS_ARROW_H__
#define __CANVAS_ARROW_H__
#include "canvas/group.h"
namespace ArdourCanvas {
class Line;
class Polygon;
/** A composite item which draws a line with arrow heads
* at either or both ends.
*
* The arrow heads are identified by the indices 0 and 1;
* head 0 is at the (x0, y0) end of the line, and head 1
* at the (x1, y1) end.
*
* @todo Draws vertical lines only; could be generalised
* to draw lines at any angle.
*/
class Arrow : public Group
{
public:
Arrow (Group *);
void set_show_head (int, bool);
void set_head_outward (int, bool);
void set_head_height (int, Distance);
void set_head_width (int, Distance);
void set_outline_width (Distance);
void set_color (Color);
Coord x () const;
Coord y1 () const;
void set_x (Coord);
void set_y0 (Coord);
void set_y1 (Coord);
private:
void setup_polygon (int);
/** Representation of a single arrow head */
struct Head {
Polygon* polygon; ///< the polygon which represents its shape
bool show; ///< true if this head should be visible
bool outward; ///< true if this head points out from the line
Distance height; ///< the height of the head
Distance width; ///< the maximum width of the head
};
/** our arrow heads; _heads[0] is at the (x0, y0) end of the line,
* and _heads[1] at the (x1, y1) end.
*/
Head _heads[2];
/** our line */
Line* _line;
};
}
#endif