/*
 * Copyright (C) 2007 Tomasz Boczkowski <tboczkowski@onet.pl>
 *
 * This file is part of the KDE project "KBounce"
 *
 * KBounce is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * KBounce 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
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with KBounce; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA  02110-1301, USA.
 */

#ifndef WALL_H
#define WALL_H

#include "kgamecanvas.h"
#include <QObject>
#include "gameobject.h"

class KBounceRenderer;
class KBounceBoard;

/**
 * KGameCanvasPixmap representing a wall "under-construction"
 *
 * There are four walls in a board, each of which extends in
 * other direction: up, right, down or left
 */ 
class KBounceWall : public QObject, public KGameCanvasPixmap
{
    Q_OBJECT

    public:
	enum Direction { Up = 0, Down, Left, Right };

	/**
	 * Constructor
	 * @param dir is set in construction and does not change in gameplay
	 * that means there will be no two walls extending in the same direction
	 * in the same time
	 */
	KBounceWall( Direction dir, KBounceRenderer* renderer, KBounceBoard* board );
	~KBounceWall();

	/**
	 * Changes object's state when collisions have been detected
	 * Called once per frame before advance() and update()
	 */
	void collide( KBounceCollision collision );
	/**
	 * Performs various movement and state calculations non-related
	 * to collision responses. Also updates m_boundingRect and 
	 * m_nextBoundingRect. This method is called once per frame
	 * after collide() and before update()
	 */
	void advance();
	/**
	 * Updates object's pixmap and position on screen
	 * Called once per frame after update()
	 */
	void update();

	/**
	 * Starts building wall beginning from tile specified by x and y
	 * The direction has been specified in constructor
	 */
	void build( int x, int y );
	/**
	 * Returns current object's bounding rect.
	 */
	QRectF boundingRect() const;
	/**
	 * Returns the bounding rect that is expected for wall to
	 * have in next frame. Collision in KBounceBoard are based on
	 * the result of this method
	 */
	QRectF nextBoundingRect() const;

	/**
	 * Changes on-screen dimensions of the wall. 
	 * Calculations are based on tile size, that is the on-screen
	 * size of board's tile
	 */
	void resize( const QSize& tileSize );

	/**
	* Set the wall velocity for wall filling speed.
	*/
	void setWallVelocity(qreal velocity);

    signals:
	void finished( int left, int top, int right, int bottom );
	void died();

    private:
	/**
	 * Returns true if rect2 intersects the edge at the end of wall
	 * e.g for wall extending in direction Up this will be the upper
	 * edge.
	 */
	bool safeEdgeHit( const QRectF& rect2 ) const;
	/**
	 * Helper function replacing emiting long finished signal
	 * It also hides the wall and plays corresponding sound
	 * If &param shorten is true the wall will be one unit in
	 * direction &param dir shorter than normal 
	 */
	void finish( bool shorten = false, Direction dir = Up);

	KBounceRenderer *m_renderer;
	KBounceBoard *m_board;
	Direction m_dir;
	QSize m_tileSize;
	QRectF m_boundingRect;
	QRectF m_nextBoundingRect;
	qreal m_wallVelocity;
};

#endif


