runtime/kioslave/thumbnail/cursorcreator.cpp

   1 /*  This file is part of the KDE libraries
   2     Copyright (C) 2003 Fredrik Höglund <fredrik@kde.org>
   3
   4     This library is free software; you can redistribute it and/or
   5     modify it under the terms of the GNU Library General Public
   6     License as published by the Free Software Foundation; either
   7     version 2 of the License, or (at your option) any later version.
   8
   9     This library is distributed in the hope that it will be useful,
  10     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12     Library General Public License for more details.
  13
  14     You should have received a copy of the GNU Library General Public License
  15     along with this library; see the file COPYING.LIB.  If not, write to
  16     the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17     Boston, MA 02110-1301, USA.
  18 */
  19
  20 #include <QImage>
  21 #include <QFile>
  22
  23 #include <kdemacros.h>
  24
  25 #include "cursorcreator.h"
  26
  27 #include <X11/Xlib.h>
  28 #include <X11/Xcursor/Xcursor.h>
  29
  30 extern "C"
  31 {
  32     KDE_EXPORT ThumbCreator *new_creator()
  33     {
  34         return new CursorCreator;
  35     }
  36 }
  37
  38 bool CursorCreator::create( const QString &path, int width, int height, QImage &img )
  39 {
  40     XcursorImage *cursor = XcursorFilenameLoadImage(
  41                     QFile::encodeName( path ).data(),
  42                     width > height ? height : width );
  43
  44     if ( cursor ) {
  45         img = QImage( reinterpret_cast<uchar *>( cursor->pixels ),
  46                         cursor->width, cursor->height, 32,
  47                         NULL, 0, QImage::BigEndian );
  48             img.setAlphaBuffer( true );
  49
  50             // Convert the image to non-premultiplied alpha
  51             quint32 *pixels = reinterpret_cast<quint32 *>( img.bits() );
  52             for ( int i = 0; i < (img.width() * img.height()); i++ ) {
  53                     float alpha = qAlpha( pixels[i] ) / 255.0;
  54                     if ( alpha > 0.0 && alpha < 1.0 )
  55                             pixels[i] = qRgba( int( qRed(pixels[i]) / alpha ),
  56                                             int( qGreen(pixels[i]) / alpha ),
  57                                             int( qBlue(pixels[i]) / alpha ),
  58                                             qAlpha(pixels[i]) );
  59             }
  60
  61             // Create a deep copy of the image so the image data is preserved
  62             img = img.copy();
  63             XcursorImageDestroy( cursor );
  64             return true;
  65     }
  66
  67     return false;
  68 }
  69