/***************************************************************************
            ImageView.h  -  simple widget class for displaying a QImage
			     -------------------
    begin                : 1999
    copyright            : (C) 1999 by Martin Wilz
    email                : Martin Wilz <mwilz@ernie.mi.uni-koeln.de>
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef IMAGEVIEW_H
#define IMAGEVIEW_H

#include "config.h"

#include <QtGlobal>
#include <QImage>
#include <QPainter>
#include <QWidget>

namespace Kwave
{
    /**
     * Simple widget class for displaying a QImage.
     */
    class Q_DECL_EXPORT ImageView: public QWidget
    {
	Q_OBJECT
    public:
	/**
	 * Constructor.
	 * @param parent pointer to the parent widget, can be 0
	 * @param fit_width if set to true, the image will be scaled to fit
	 *        horizontally into the widget; if false the image will be
	 *        cut off at the edge and should be scrolled
	 * @param fit_height if set to true, the image will be scaled to fit
	 *        vertically into the widget; if false the image will be
	 *        cut off at the edge and should be scrolled
	 */
	explicit ImageView(QWidget *parent = 0,
	                   bool fit_width = true,
	                   bool fit_height = true);

	/**
	 * Destructor
	 */
	virtual ~ImageView();

	/**
	 * Returns the position and size of the current image, packed
	 * into a QRect object.
	 * @return rectangle with the image coordinates and size
	 */
	QRect imageRect();

    public slots:

	/**
	* Sets a new QImage for displaying.
	* @param image a pointer to the image
	*/
	void setImage(QImage image);

	/** sets a new horizontal offset, useful for scrolling */
	void setHorizOffset(int offset);

	/** sets a new vertical offset, useful for scrolling */
	void setVertOffset(int offset);

    signals:

	void viewInfo(int, int, int);
	void sigCursorPos(const QPoint pos);

    protected:

	void mouseMoveEvent(QMouseEvent *e);

	void mousePressEvent(QMouseEvent *e);

	void paintEvent(QPaintEvent *);

    private:
	/**
	 * offset of the image, in original unscaled coordinates
	 * of the internal QImage
	 */
	QPoint m_offset;

	/**
	 * last displayed image rectangle. Note that the left and
	 * top coordinates are unscaled, but the width and height
	 * might be scaled to screen coordinates!
	 */
	QRect m_last_rect;

	/** pointer to the QImage to be displayed */
	QImage m_image;

	/** if true, scale to fit horizontally */
	bool m_fit_width;

	/** if true, scale to fit vertically */
	bool m_fit_height;

	/**
	 * scale factor in horizontal direction, will be
	 * (width of the image / width of the widget) if m_fit_width
	 * is true, or 1.0 else
	 */
	double m_scale_x;

	/**
	 * scale factor in vertical direction, will be
	 * (height of the image / height of the widget) if m_fit_height
	 * is true, or 1.0 else
	 */
	double m_scale_y;

    };
}

#endif // _IMAGEVIEW_H_

//***************************************************************************
//***************************************************************************
