wesnoth/src/mouse_handler_base.hpp

/* $Id$ */
/*
   Copyright (C) 2006 - 2009 by Joerg Hinrichs <joerg.hinrichs@alice-dsl.de>
   wesnoth playturn Copyright (C) 2003 by David White <dave@whitevine.net>
   Part of the Battle for Wesnoth Project http://www.wesnoth.org/

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License version 2
   or at your option any later version.
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY.

   See the COPYING file for more details.
*/

#ifndef MOUSE_HANDLER_BASE_H_INCLUDED
#define MOUSE_HANDLER_BASE_H_INCLUDED

#include "display.hpp"
#include "map_location.hpp"
#include "SDL.h"

namespace events {

struct command_disabler
{
	command_disabler();
	~command_disabler();
};

extern int commands_disabled;

class mouse_handler_base {
public:
	mouse_handler_base();
	virtual ~mouse_handler_base() {}

	/**
	 * Reference to the used display objects. Derived classes should ensure
	 * this is always valid. Note the constructor of this class cannot use this.
	 */
	virtual display& gui() = 0;

	/**
	 * Const version.
	 */
	virtual const display& gui() const = 0;

	/**
	 * @return true when the class in the "dragging" state.
	 */
	bool is_dragging() const;

	void mouse_motion_event(const SDL_MouseMotionEvent& event, const bool browse);

	/** update the mouse with a fake mouse motion */
	void mouse_update(const bool browse);

	bool get_show_menu() const { return show_menu_; }

	/**
	 * This handles minimap scrolling and click-drag.
	 * @returns true when the caller should not process the mouse motion
	 * further (i.e. should return), false otherwise.
	 */
	bool mouse_motion_default(int x, int y, bool& update);

	/**
	 * Called when a mouse motion event takes place. Derived classes mustprovide an
	 * implementation, possibly using mouse_motion_default().
	 */
	virtual void mouse_motion(int x, int y, const bool browse, bool update=false) = 0;

	virtual void mouse_press(const SDL_MouseButtonEvent& event, const bool browse);
	bool is_left_click(const SDL_MouseButtonEvent& event);
	bool is_middle_click(const SDL_MouseButtonEvent& event);
	bool is_right_click(const SDL_MouseButtonEvent& event);

	/**
	 * Derived classes can overrid this to disable mousewheel scrolling under
	 * some circumstances, e.g. when the mouse wheel controls something else,
	 * but the event is also received by this class
	 */
	virtual bool allow_mouse_wheel_scroll(int x, int y);

	/**
	 * Overriden in derived classes, called on a right click (mousedown).
	 * Defaults to process (initiate) minimap scrolling.
	 * @returns true when the click should not process the event further.
	 * This means do not treat the call as a start of drag movement.
	 */
	virtual bool left_click(int x, int y, const bool browse);

	/**
	 * Called whenever the left mouse drag has "ended".
	 */
	virtual void left_drag_end(int x, int y, const bool browse);

	/**
	 * Called when the left mouse button is up
	 */
	virtual void left_mouse_up(int x, int y, const bool browse);

	/**
	 * Overriden in derived classes, called on a right click (mousedown).
	 * Defaults to displaying the menu (by setting the appropriate flag)
	 * if right_click_show_menu returns true.
	 * @returns true when the click should not process the event further.
	 * This means do not treat the call as a start of drag movement.
	 */
	virtual bool right_click(int x, int y, const bool browse);

	/**
	 * Called in the default right_click when the context menu is about to
	 * be shown, can be used for preprocessing and preventing the menu from
	 * being displayed without rewriting the right click function.
	 * @returns true when the menu should be displayed and false otherwise
	 */
	virtual bool right_click_show_menu(int x, int y, const bool browse);

	/**
	 * Called whenever the right mouse drag has "ended".
	 */
	virtual void right_drag_end(int x, int y, const bool browse);

	/**
	 * Called when the right mouse button is up
	 */
	virtual void right_mouse_up(int x, int y, const bool browse);

protected:
	void clear_dragging(const SDL_MouseButtonEvent& event, bool browse);
	void init_dragging(bool& dragging_flag);

	/** MMB click (on game map) state flag */
	bool simple_warp_;
	/** minimap scrolling (scroll-drag) state flag */
	bool minimap_scrolling_;
	/** LMB drag init flag */
	bool dragging_left_;
	/** Actual drag flag */
	bool dragging_started_;
	/** RMB drag init flag */
	bool dragging_right_;
	/** Drag start position x */
	int drag_from_x_;
	/** Drag start position y */
	int drag_from_y_;
	/** Drag start map location */
	map_location drag_from_hex_;

	/** last highlighted hex */
	map_location last_hex_;

	/** Show context menu flag */
	bool show_menu_;

	static const int drag_threshold_;
};

} // end namespace events

#endif