/*
 *  This file is part of the KDE libraries
 *  Copyright (C) 1998 Mark Donohoe <donohoe@kde.org>
 *    Stephan Kulow <coolo@kde.org>
 *
 *  $Id: kpixmap.h,v 1.32 2004/09/09 20:44:57 staniek Exp $
 *
 *  This library 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.
 *
 *  This library 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 this library; see the file COPYING.LIB.  If not, write to
 *  the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 *  Boston, MA 02111-1307, USA.
 */

#ifndef __KPIXMAP_H__
#define __KPIXMAP_H__

#include <qpixmap.h>

#include <kdelibs_export.h>

const int KColorMode_Mask = 0x00000300;
const int WebOnly  = 0x00000200;
const int LowOnly = 0x00000300;

class KPixmapPrivate;

/**
 * Off-screen paint device with extended features.

 * KPixmap has two new color modes, WebColor and LowColor, applicable
 * to 8bpp displays.

 * In WebColor mode all images are dithered to the Netscape palette,
 * even when they have their own color table. WebColor is the default
 * mode for KPixmap so that standard applications can share the Netscape
 * palette across the desktop.

 * In LowColor mode images are checked to see if their color table
 * matches the KDE icon palette. If the color tables do not match, the
 * images are dithered to a minimal 3x3x3 color cube. LowColor mode can
 * be used to load icons, background images etc. so that components of
 * the desktop which are always present use no more than 40 colors.

 * @author Mark Donohoe (donohoe@kde.org)
 * @version $Id: kpixmap.h,v 1.32 2004/09/09 20:44:57 staniek Exp $
 */
class KDEFX_EXPORT KPixmap : public QPixmap
{
public:
    /**
     * This enumeration provides a color pallete specification
     * @see KPixmap::convertFromImage(), KPixmap::load()
     */
    enum ColorMode { Auto,   //!< Convert to monochrome if possible
                     Color,  //!< Native display depth
                     Mono,   //!< Monochrome pixmap
                     LowColor, //!< 3x3x3 color cube (or monochrome)
                     WebColor //!< Netscape pallete (or monochrome)
                   };
    /**
     * This enumeration provides a gradient mode specification
     */
    enum GradientMode { Horizontal,
                        Vertical,
                        Diagonal,
                        CrossDiagonal
                      };

    /**
     * Constructs a null pixmap.
     */
    KPixmap() : QPixmap() {};

    /**
     * Destructs the pixmap.
            * ### KDE 4: remove
     */
    ~KPixmap();

    /**
     * Copies the QPixmap @p pix.
            */
    KPixmap(const QPixmap& pix);

    /**
     * Converts an image and sets this pixmap.
     *
     * The conversion_flags argument is a bitwise-OR from the
     * following choices. The options marked (default) are the
     * choice if no other choice from the list is included (they
     * are zero):
     *
     * Color/Mono preference
     *
     * @li WebColor -  If the image has depth 1 and contains
     * only black and white pixels then the pixmap becomes monochrome. If
     * the pixmap has a depth of 8 bits per pixel then the Netscape
     * palette is used for the pixmap color table.
     * @li LowColor - If the image has depth 1 and contains only black and
     * white pixels then the pixmap becomes monochrome. If the pixmap has a
     * depth of 8 bits per pixel and the image does not posess a color table
     * that matches the Icon palette a 3x3x3 color cube is used for the
     * pixmap color table.
     * @li AutoColor (default) - If the image has depth 1 and contains
     * only black and white pixels, then the pixmap becomes
     * monochrome.
     * @li ColorOnly - The pixmap is dithered/converted to the native
     * display depth.
     * @li MonoOnly - The pixmap becomes monochrome. If necessary, it
     * is dithered using the chosen dithering algorithm.
     *
     * Dithering mode preference, for RGB channels
     *
     * @li DiffuseDither (default) - A high quality dither.
     * @li OrderedDither - A faster more ordered dither.
     * @li ThresholdDither - No dithering, closest color is used.
     *
     * Dithering mode preference, for alpha channel
     *
     * @li DiffuseAlphaDither - A high quality dither.
     * @li OrderedAlphaDither - A faster more ordered dither.
     * @li ThresholdAlphaDither (default) - No dithering.
     *
     * Color matching versus dithering preference
     *
     * @li PreferDither - Always dither 32-bit images when the image
     * is being converted to 8-bits. This is the default when
     * converting to a pixmap.
     * @li AvoidDither - Only dither 32-bit images if the image has
     * more than 256 colors and it is being converted to 8-bits.
     * This is the default when an image is converted for the
     * purpose of saving to a file.
     *
     * Passing 0 for @p conversion_flags gives all the default
     * options.
     *
     * @param img the image to convert
     * @param conversion_flags bitmask, described above
     * @return @p true if successful.
     **/
    bool convertFromImage( const QImage &img, int conversion_flags );

    /**
     * This is an overloaded member function, provided for
     * convenience. It differs from the above function only in
     * what argument(s) it accepts.
     * @param img the image to convert
     * @param mode a ColorMode to apply
     * @return @p true if successful.
     **/
    bool convertFromImage( const QImage &img, ColorMode mode = WebColor );

    /**
     * Loads a pixmap from the file @p fileName.
     *
     * If format is specified, the loader attempts to read the
     * pixmap using the specified format. If format is not
     * specified (default), the loader reads a few bytes from the
     * header to guess the file format.
     *
     * The QImageIO documentation lists the supported image
     * formats and explains how to add extra formats.
     *
     * @param fileName the name of the file to load the image from
     * @param format the format for the image
     * @param conversion_flags a bitmask, as described in
     *        convertFromImage()
     * @return @p true if successful, or false if the pixmap
     *         could not be loaded.
     **/
    bool load( const QString& fileName, const char *format,
               int conversion_flags );

    /**
     * This is an overloaded member function, provided for
     * convenience. It differs from the above function only in
     * what argument(s) it accepts.
     * @param fileName the name of the file to load the image from
     * @param format the format for the image
     * @param mode a ColorMode to apply
     * @return @p true if successful, or false if the pixmap
     *         could not be loaded.
     **/
    bool load( const QString& fileName,
               const char *format = 0,
               ColorMode mode = WebColor );

    /**
     * Returns true if the image posesses a color table that
     * matches the Icon palette or false otherwise.
     *
     * An image with one color not found in the Icon palette is
     * considered to be a match, since this extra color may be a
     * transparent background.
     * @param image the image to test
     **/
    bool checkColorTable(const QImage &image);

private:
    KPixmapPrivate *d;
};

#endif