/***************************************************************************
            ClipBoard.h  -  the Kwave clipboard
			     -------------------
    begin                : Tue Jun 26, 2001
    copyright            : (C) 2001 by Thomas Eschenbacher
    email                : Thomas Eschenbacher <thomas.eschenbacher@gmx.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 CLIP_BOARD_H
#define CLIP_BOARD_H

#include "config.h"

#include <QClipboard>
#include <QtGlobal>
#include <QObject>

#include "libkwave/Sample.h"

class QWidget;

namespace Kwave
{

    class SignalManager;

    /**
     * Implements a global clipboard for Kwave. It supports only the three
     * simple operations <c>put</c>, <c>get</c> and <c>clear</c>.
     */
    class Q_DECL_EXPORT ClipBoard: public QObject
    {
	Q_OBJECT
    public:

	/** Constructor. */
	ClipBoard();

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

	/** returns the static instance of the clipboard */
	static ClipBoard &instance();

	/**
	 * Discards the current content of the clipboard and fills
	 * it with a selected range of samples from a set of tracks.
	 * @param widget the widget used as parent for displaying
	 *               error messages
	 * @param signal_manager the SignalManager with the tracks to read from
	 * @param track_list a list of indices of tracks for reading
	 * @param offset first sample to copy
	 * @param length number of samples
	 */
	void copy(QWidget *widget, Kwave::SignalManager &signal_manager,
	          const QList<unsigned int> &track_list,
	          sample_index_t offset, sample_index_t length);

	/**
	 * Transfers all stored data from the clipboard into a SignalManager.
	 *
	 * @param widget the widget used as parent for displaying
	 *               error messages
	 * @param signal_manager the SignalManager with the tracks to write to
	 * @param offset sample position where to paste
	 * @param length length of the current selection in samples
	 * @return true if successful, false if failed
	 */
	bool paste(QWidget *widget, Kwave::SignalManager &signal_manager,
	           sample_index_t offset, sample_index_t length);

	/**
	 * Clears the internal buffers. The clipboard will be empty after this
	 * function returns and the sample rate will be set to zero.
	 */
	void clear();

	/**
	 * Returns true if the buffer is empty.
	 */
	bool isEmpty();

    signals:

	/**
	 * Emitted whenever the clipboard has changed from empty
	 * to non-empty (with decodeable data) or vice versa.
	 * @param data_available if true: contains decodeable data,
	 *                       if false: nothing decodeable or empty
	 */
	void clipboardChanged(bool data_available);

    public slots:

	/**
	 * emits clipboardChanged() whenever the clipboard has changed
	 * from empty to filled (with decodeable data) or vice versa
	 * (connected to the Qt clipboard)
	 */
	void slotChanged(QClipboard::Mode mode);

    private:

	/** number of tracks of the content */
	unsigned int m_tracks;

    };
}

#endif /* CLIP_BOARD_H */

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