/*
    Copyright (C) 2009 Paul Davis 

    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.

*/

#include <gtkmm/menu.h>
#include "editor_component.h"
#include "cairo_widget.h"

namespace ARDOUR {
	class Session;
	class RouteGroup;
}

class Editor;

/** Parent class for tabs which represent route groups as coloured tabs;
 *  Currently used on the left-hand side of the editor and at the top of the mixer.
 */
class GroupTabs : public CairoWidget, public EditorComponent
{
public:
	GroupTabs (Editor *);

	void connect_to_session (ARDOUR::Session *);

protected:

	struct Tab {
		double from; ///< start coordinate
		double to; ///< end coordinate
		Gdk::Color colour; ///< colour
		ARDOUR::RouteGroup* group; ///< route group
		double first_ui_size; ///< GUI size of the first route in the group
		double last_ui_size; ///< GUI size of the last route in the group
	};

private:
	/** Compute all the tabs for this widget.
	 *  @return Tabs.
	 */
	virtual std::list<Tab> compute_tabs () const = 0;

	/** Draw a tab.
	 *  @param cr Cairo context.
	 *  @param t Tab.
	 */
	virtual void draw_tab (cairo_t* cr, Tab const & t) const = 0;

	/** @param x x coordinate
	 *  @param y y coordinate
	 *  @return x or y, depending on which is the primary coordinate for this widget.
	 */
	virtual double primary_coordinate (double, double) const = 0;

	/** Take a list of tabs and alter the route groups to reflect the tabs.
	 *  @param tabs.
	 */
	virtual void reflect_tabs (std::list<Tab> const & tabs) = 0;

	/** @return Size of the widget along the primary axis */
	virtual double extent () const = 0;

	/** @param g Route group, or 0.
         *  @return Menu to be popped up on right-click over the given route group.
	 */
	virtual Gtk::Menu* get_menu (ARDOUR::RouteGroup* g) = 0;

	void render (cairo_t *);
	void on_size_request (Gtk::Requisition *);
	bool on_button_press_event (GdkEventButton *);
	bool on_motion_notify_event (GdkEventMotion *);
	bool on_button_release_event (GdkEventButton *);

	Tab * click_to_tab (double, Tab**, Tab**);

	std::list<Tab> _tabs; ///< current list of tabs
	Tab* _dragging; ///< tab being dragged, or 0
	bool _drag_moved; ///< true if there has been movement during any current drag
	bool _drag_from; ///< true if the drag is of the `from' end of the tab, otherwise it's the `to' end
	double _drag_last; ///< last mouse pointer position during drag
	double _drag_limit; ///< limit of the current drag
};