/****************************************************************************
** Copyright (C) 2001-2011 Klaralvdalens Datakonsult AB.  All rights reserved.
**
** This file is part of the KD Chart library.
**
** Licensees holding valid commercial KD Chart licenses may use this file in
** accordance with the KD Chart Commercial License Agreement provided with
** the Software.
**
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 and version 3 as published by the
** Free Software Foundation and appearing in the file LICENSE.GPL.txt included.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
** Contact info@kdab.com if any conditions of this licensing are not
** clear to you.
**
**********************************************************************/

#ifndef __KDCHART_PALETTE_H__
#define __KDCHART_PALETTE_H__

#include <QObject>
#include <QBrush>
#include "KDChartGlobal.h"

namespace KDChart {

  /**
   * \brief A Palette is a set of brushes (or colors) to be used
   * for painting data sets.
   *
   * The palette class encapsulates a colletion of brushes, which in
   * the simplest case are colors, to be used for painting a series of
   * data sets. When asked for the m-th color, a palette of size n will
   * wrap around and thus cycle through the available colors.
   *
   * Three builtin palettes are provided for convenience, one with a default
   * set of colors, one with a subdued color selection, one with rainbow
   * colors.
   *
   * When a palette changes, it emits a changed() signal. Hook up to it, if
   * you want to repaint when the color selection changes.
   */

class KDCHART_EXPORT Palette: public QObject
{
    Q_OBJECT
public:
    explicit Palette( QObject *parent  = 0 );
    Palette( const Palette& );
    Palette &operator= ( const Palette & );

    ~Palette();

    /** Provide access to the three builtin palettes, one with standard bright
     * colors, one with more subdued colors, and one with rainbow colors.  */
    static const Palette& defaultPalette();
    static const Palette& subduedPalette();
    static const Palette& rainbowPalette();

    /** @return whether this represents a valid palette. For a palette to be
     * valid it needs to have at least one brush associated. */
    bool isValid() const;

    /** @return the number of brushed in the palette.  */
    int size() const;

    /** Adds \a brush to the palette. If no \a position is specified, the
     * brush is appended. 
     */
    void addBrush( const QBrush & brush, int position = -1 );

    /**
     * Query the palette for a brush at the specified position. If the
     * position exceeds the size of the palette, it wraps around.
     */
    QBrush getBrush( int position ) const;

    /** Remove the brush at position \a position, if there is one.  */
    void removeBrush( int position );

Q_SIGNALS:
    /**  Emitted whenever the palette changes. Views listen to this and
     * repaing.  */
    void changed();

private:
    KDCHART_DECLARE_PRIVATE_BASE_VALUE( Palette )
};

}
KDCHART_DECLARE_SWAP_SPECIALISATION( KDChart::Palette )
#endif