workspace/plasma/wallpapers/image/renderthread.cpp

   1 /*
   2   Copyright (c) 2007 Paolo Capriotti <p.capriotti@gmail.com>
   3
   4   This program is free software; you can redistribute it and/or modify
   5   it under the terms of the GNU General Public License as published by
   6   the Free Software Foundation; either version 2 of the License, or
   7   (at your option) any later version.
   8 */
   9
  10 #include "renderthread.h"
  11
  12 #include <QPainter>
  13 #include <QFile>
  14 #include <KDebug>
  15 #include <KSvgRenderer>
  16
  17 RenderThread::RenderThread()
  18 : m_current_token(-1)
  19 , m_size(0, 0)
  20 , m_ratio(1.0)
  21 {
  22     m_abort = false;
  23     m_restart = false;
  24 }
  25
  26 RenderThread::~RenderThread()
  27 {
  28     {
  29         // abort computation
  30         QMutexLocker lock(&m_mutex);
  31         m_abort = true;
  32         m_condition.wakeOne();
  33     }
  34
  35     wait();
  36 }
  37
  38 void RenderThread::setSize(const QSize& size)
  39 {
  40     QMutexLocker lock(&m_mutex);
  41     m_size = size;
  42 }
  43
  44 void RenderThread::setRatio(float ratio)
  45 {
  46     QMutexLocker lock(&m_mutex);
  47     m_ratio = ratio;
  48 }
  49
  50 int RenderThread::render(const QString &file,
  51                           const QColor &color,
  52                           Background::ResizeMethod method,
  53                           Qt::TransformationMode mode)
  54 {
  55     int token;
  56     {
  57         QMutexLocker lock(&m_mutex);
  58         m_file = file;
  59         m_color = color;
  60         m_method = method;
  61         m_mode = mode;
  62         m_restart = true;
  63         token = ++m_current_token;
  64     }
  65
  66     if (!isRunning()) {
  67         start();
  68     }
  69     else {
  70         m_condition.wakeOne();
  71     }
  72
  73     return token;
  74 }
  75
  76 void RenderThread::run()
  77 {
  78     QString file;
  79     QColor color;
  80     QSize size;
  81     float ratio;
  82     Background::ResizeMethod method;
  83     Qt::TransformationMode mode;
  84     int token;
  85
  86     forever {
  87         {
  88             QMutexLocker lock(&m_mutex);
  89
  90             while (!m_restart && !m_abort) {
  91                 m_condition.wait(&m_mutex);
  92             }
  93
  94             if (m_abort) {
  95                 return;
  96             }
  97
  98             m_restart = false;
  99
 100             // load all parameters in nonshared variables
 101             token = m_current_token;
 102             file = m_file;
 103             color = m_color;
 104             size = m_size;
 105             ratio = m_ratio;
 106             method = m_method;
 107             mode = m_mode;
 108         }
 109
 110         QImage result(size, QImage::Format_ARGB32_Premultiplied);
 111         result.fill(color.rgba());
 112
 113         if (file.isEmpty() || !QFile::exists(file)) {
 114             emit done(token, result);
 115             continue;
 116         }
 117
 118         QPoint pos(0, 0);
 119         bool tiled = false;
 120         bool scalable = file.endsWith("svg") || file.endsWith("svgz");
 121         QSize scaledSize;
 122         QImage img;
 123
 124         // set image size
 125         QSize imgSize;
 126         if (scalable) {
 127             // scalable: image can be of any size
 128             imgSize = size;
 129         } else {
 130             // otherwise, use the natural size of the loaded image
 131             img = QImage(file);
 132             imgSize = img.size();
 133             kDebug() << "loaded with" << imgSize << ratio;
 134         }
 135
 136         // if any of them is zero we may run into a div-by-zero below.
 137         if (imgSize.width() < 1) {
 138             imgSize.setWidth(1);
 139         }
 140
 141         if (imgSize.height() < 1) {
 142             imgSize.setHeight(1);
 143         }
 144
 145         // set render parameters according to resize mode
 146         switch (method)
 147         {
 148         case Background::Scale:
 149             imgSize *= ratio;
 150             scaledSize = size;
 151             break;
 152         case Background::Center:
 153             scaledSize = imgSize;
 154             pos = QPoint((size.width() - scaledSize.width()) / 2,
 155                         (size.height() - scaledSize.height()) / 2);
 156
 157             //If the picture is bigger than the screen, shrink it
 158             if (size.width() < imgSize.width() && imgSize.width() > imgSize.height()) {
 159                 int width = size.width();
 160                 int height = width * scaledSize.height() / imgSize.width();
 161                 scaledSize = QSize(width, height);
 162                 pos = QPoint((size.width() - scaledSize.width()) / 2,
 163                              (size.height() - scaledSize.height()) / 2);
 164             } else if (size.height() < imgSize.height()) {
 165                 int height = size.height();
 166                 int width = height * imgSize.width() / imgSize.height();
 167                 scaledSize = QSize(width, height);
 168                 pos = QPoint((size.width() - scaledSize.width()) / 2,
 169                              (size.height() - scaledSize.height()) / 2);
 170             }
 171
 172             break;
 173         case Background::Maxpect: {
 174             imgSize *= ratio;
 175             float xratio = (float) size.width() / imgSize.width();
 176             float yratio = (float) size.height() / imgSize.height();
 177             if (xratio > yratio) {
 178                 int height = size.height();
 179                 int width = height * imgSize.width() / imgSize.height();
 180                 scaledSize = QSize(width, height);
 181             } else {
 182                 int width = size.width();
 183                 int height = width * imgSize.height() / imgSize.width();
 184                 scaledSize = QSize(width, height);
 185             }
 186             pos = QPoint((size.width() - scaledSize.width()) / 2,
 187                         (size.height() - scaledSize.height()) / 2);
 188             break;
 189         }
 190         case Background::ScaleCrop: {
 191             imgSize *= ratio;
 192             float xratio = (float) size.width() / imgSize.width();
 193             float yratio = (float) size.height() / imgSize.height();
 194             if (xratio > yratio) {
 195                 int width = size.width();
 196                 int height = width * imgSize.height() / imgSize.width();
 197                 scaledSize = QSize(width, height);
 198             } else {
 199                 int height = size.height();
 200                 int width = height * imgSize.width() / imgSize.height();
 201                 scaledSize = QSize(width, height);
 202             }
 203             pos = QPoint((size.width() - scaledSize.width()) / 2,
 204                         (size.height() - scaledSize.height()) / 2);
 205             break;
 206         }
 207         case Background::Tiled:
 208             scaledSize = imgSize;
 209             tiled = true;
 210             break;
 211         case Background::CenterTiled:
 212             scaledSize = imgSize;
 213             pos = QPoint(
 214                 -scaledSize.width() +
 215                     ((size.width() - scaledSize.width()) / 2) % scaledSize.width(),
 216                 -scaledSize.height() +
 217                     ((size.height() - scaledSize.height()) / 2) % scaledSize.height());
 218             tiled = true;
 219             break;
 220         }
 221
 222         QPainter p(&result);
 223         kDebug() << token << scalable << scaledSize << imgSize;
 224         if (scalable) {
 225             // tiling is ignored for scalable wallpapers
 226             KSvgRenderer svg(file);
 227             if (m_restart) {
 228                 continue;
 229             }
 230             svg.render(&p);
 231         } else {
 232             if (scaledSize != imgSize) {
 233                 img = img.scaled(scaledSize, Qt::IgnoreAspectRatio, mode);
 234             }
 235
 236             if (m_restart) {
 237                 continue;
 238             }
 239
 240             if (tiled) {
 241                 for (int x = pos.x(); x < size.width(); x += scaledSize.width()) {
 242                     for (int y = pos.y(); y < size.height(); y += scaledSize.height()) {
 243                         p.drawImage(QPoint(x, y), img);
 244                         if (m_restart) {
 245                             goto endLoop;
 246                         }
 247                     }
 248                 }
 249             } else {
 250                 p.drawImage(pos, img);
 251             }
 252         }
 253
 254         // signal we're done
 255         emit done(token, result);
 256         endLoop: continue;
 257     }
 258 }