Split image handler plugin project files

One pri for each handler, e.g. src/gui/image/qjpeghandler.pri.
One pri for each 3rd party package, e.g src/3rdparty/libjpeg.pri.
One shared pri for zlib dependency of 3rd party packages.

This was really about image handler plugins, but PNG got the
same treatment for consistency's sake.

Also, moved image handler source files from plugins to src/gui/image
so they are with the other image handlers.

Merge-request: 715
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

1 files changed, 901 insertions, 0 deletions

diff --git a/src/gui/image/qjpeghandler.cpp b/src/gui/image/qjpeghandler.cpp
new file mode 100644
index 0000000000..60e7cce913
--- /dev/null
+++ b/src/gui/image/qjpeghandler.cpp
@@ -0,0 +1,901 @@
+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qjpeghandler.h"
+
+#include <qimage.h>
+#include <qvariant.h>
+#include <qvector.h>
+#include <qbuffer.h>
+
+#include <stdio.h>      // jpeglib needs this to be pre-included
+#include <setjmp.h>
+
+#ifdef FAR
+#undef FAR
+#endif
+
+// including jpeglib.h seems to be a little messy
+extern "C" {
+// mingw includes rpcndr.h but does not define boolean
+#if defined(Q_OS_WIN) && defined(Q_CC_GNU)
+#   if defined(__RPCNDR_H__) && !defined(boolean)
+        typedef unsigned char boolean;
+#       define HAVE_BOOLEAN
+#   endif
+#endif
+
+#define XMD_H           // shut JPEGlib up
+#if defined(Q_OS_UNIXWARE)
+#  define HAVE_BOOLEAN  // libjpeg under Unixware seems to need this
+#endif
+#include <jpeglib.h>
+#ifdef const
+#  undef const          // remove crazy C hackery in jconfig.h
+#endif
+}
+
+QT_BEGIN_NAMESPACE
+
+struct my_error_mgr : public jpeg_error_mgr {
+    jmp_buf setjmp_buffer;
+};
+
+#if defined(Q_C_CALLBACKS)
+extern "C" {
+#endif
+
+static void my_error_exit (j_common_ptr cinfo)
+{
+    my_error_mgr* myerr = (my_error_mgr*) cinfo->err;
+    char buffer[JMSG_LENGTH_MAX];
+    (*cinfo->err->format_message)(cinfo, buffer);
+    qWarning("%s", buffer);
+    longjmp(myerr->setjmp_buffer, 1);
+}
+
+#if defined(Q_C_CALLBACKS)
+}
+#endif
+
+
+static const int max_buf = 4096;
+
+struct my_jpeg_source_mgr : public jpeg_source_mgr {
+    // Nothing dynamic - cannot rely on destruction over longjump
+    QIODevice *device;
+    JOCTET buffer[max_buf];
+    const QBuffer *memDevice;
+
+public:
+    my_jpeg_source_mgr(QIODevice *device);
+};
+
+#if defined(Q_C_CALLBACKS)
+extern "C" {
+#endif
+
+static void qt_init_source(j_decompress_ptr)
+{
+}
+
+static boolean qt_fill_input_buffer(j_decompress_ptr cinfo)
+{
+    my_jpeg_source_mgr* src = (my_jpeg_source_mgr*)cinfo->src;
+    if (src->memDevice) {
+        src->next_input_byte = (const JOCTET *)(src->memDevice->data().constData() + src->memDevice->pos());
+        src->bytes_in_buffer = (size_t)(src->memDevice->data().size() - src->memDevice->pos());
+        return true;
+    }
+    src->next_input_byte = src->buffer;
+    int num_read = src->device->read((char*)src->buffer, max_buf);
+    if (num_read <= 0) {
+        // Insert a fake EOI marker - as per jpeglib recommendation
+        src->buffer[0] = (JOCTET) 0xFF;
+        src->buffer[1] = (JOCTET) JPEG_EOI;
+        src->bytes_in_buffer = 2;
+    } else {
+        src->bytes_in_buffer = num_read;
+    }
+#if defined(Q_OS_UNIXWARE)
+    return B_TRUE;
+#else
+    return true;
+#endif
+}
+
+static void qt_skip_input_data(j_decompress_ptr cinfo, long num_bytes)
+{
+    my_jpeg_source_mgr* src = (my_jpeg_source_mgr*)cinfo->src;
+
+    // `dumb' implementation from jpeglib
+
+    /* Just a dumb implementation for now.  Could use fseek() except
+     * it doesn't work on pipes.  Not clear that being smart is worth
+     * any trouble anyway --- large skips are infrequent.
+     */
+    if (num_bytes > 0) {
+        while (num_bytes > (long) src->bytes_in_buffer) {  // Should not happen in case of memDevice
+            num_bytes -= (long) src->bytes_in_buffer;
+            (void) qt_fill_input_buffer(cinfo);
+            /* note we assume that qt_fill_input_buffer will never return false,
+            * so suspension need not be handled.
+            */
+        }
+        src->next_input_byte += (size_t) num_bytes;
+        src->bytes_in_buffer -= (size_t) num_bytes;
+    }
+}
+
+static void qt_term_source(j_decompress_ptr cinfo)
+{
+    my_jpeg_source_mgr* src = (my_jpeg_source_mgr*)cinfo->src;
+    if (!src->device->isSequential())
+    {
+        // read() isn't used for memDevice, so seek past everything that was used
+        if (src->memDevice)
+            src->device->seek(src->device->pos() + (src->memDevice->data().size() - src->memDevice->pos() - src->bytes_in_buffer));
+        else
+            src->device->seek(src->device->pos() - src->bytes_in_buffer);
+    }
+}
+
+#if defined(Q_C_CALLBACKS)
+}
+#endif
+
+inline my_jpeg_source_mgr::my_jpeg_source_mgr(QIODevice *device)
+{
+    jpeg_source_mgr::init_source = qt_init_source;
+    jpeg_source_mgr::fill_input_buffer = qt_fill_input_buffer;
+    jpeg_source_mgr::skip_input_data = qt_skip_input_data;
+    jpeg_source_mgr::resync_to_restart = jpeg_resync_to_restart;
+    jpeg_source_mgr::term_source = qt_term_source;
+    this->device = device;
+    memDevice = qobject_cast<QBuffer *>(device);
+    bytes_in_buffer = 0;
+    next_input_byte = buffer;
+}
+
+
+inline static bool read_jpeg_size(int &w, int &h, j_decompress_ptr cinfo)
+{
+    (void) jpeg_calc_output_dimensions(cinfo);
+
+    w = cinfo->output_width;
+    h = cinfo->output_height;
+    return true;
+}
+
+#define HIGH_QUALITY_THRESHOLD 50
+
+inline static bool read_jpeg_format(QImage::Format &format, j_decompress_ptr cinfo)
+{
+
+    bool result = true;
+    switch (cinfo->output_components) {
+    case 1:
+        format = QImage::Format_Indexed8;
+        break;
+    case 3:
+    case 4:
+        format = QImage::Format_RGB32;
+        break;
+    default:
+        result = false;
+        break;
+    }
+    cinfo->output_scanline = cinfo->output_height;
+    return result;
+}
+
+static bool ensureValidImage(QImage *dest, struct jpeg_decompress_struct *info,
+                             const QSize& size)
+{
+    QImage::Format format;
+    switch (info->output_components) {
+    case 1:
+        format = QImage::Format_Indexed8;
+        break;
+    case 3:
+    case 4:
+        format = QImage::Format_RGB32;
+        break;
+    default:
+        return false; // unsupported format
+    }
+
+    if (dest->size() != size || dest->format() != format) {
+        *dest = QImage(size, format);
+
+        if (format == QImage::Format_Indexed8) {
+            dest->setColorCount(256);
+            for (int i = 0; i < 256; i++)
+                dest->setColor(i, qRgb(i,i,i));
+        }
+    }
+
+    return !dest->isNull();
+}
+
+static bool read_jpeg_image(QImage *outImage,
+                            QSize scaledSize, QRect scaledClipRect,
+                            QRect clipRect, int inQuality, j_decompress_ptr info, struct my_error_mgr* err  )
+{
+    if (!setjmp(err->setjmp_buffer)) {
+        // -1 means default quality.
+        int quality = inQuality;
+        if (quality < 0)
+            quality = 75;
+
+        // If possible, merge the scaledClipRect into either scaledSize
+        // or clipRect to avoid doing a separate scaled clipping pass.
+        // Best results are achieved by clipping before scaling, not after.
+        if (!scaledClipRect.isEmpty()) {
+            if (scaledSize.isEmpty() && clipRect.isEmpty()) {
+                // No clipping or scaling before final clip.
+                clipRect = scaledClipRect;
+                scaledClipRect = QRect();
+            } else if (scaledSize.isEmpty()) {
+                // Clipping, but no scaling: combine the clip regions.
+                scaledClipRect.translate(clipRect.topLeft());
+                clipRect = scaledClipRect.intersected(clipRect);
+                scaledClipRect = QRect();
+            } else if (clipRect.isEmpty()) {
+                // No clipping, but scaling: if we can map back to an
+                // integer pixel boundary, then clip before scaling.
+                if ((info->image_width % scaledSize.width()) == 0 &&
+                        (info->image_height % scaledSize.height()) == 0) {
+                    int x = scaledClipRect.x() * info->image_width /
+                            scaledSize.width();
+                    int y = scaledClipRect.y() * info->image_height /
+                            scaledSize.height();
+                    int width = (scaledClipRect.right() + 1) *
+                                info->image_width / scaledSize.width() - x;
+                    int height = (scaledClipRect.bottom() + 1) *
+                                 info->image_height / scaledSize.height() - y;
+                    clipRect = QRect(x, y, width, height);
+                    scaledSize = scaledClipRect.size();
+                    scaledClipRect = QRect();
+                }
+            } else {
+                // Clipping and scaling: too difficult to figure out,
+                // and not a likely use case, so do it the long way.
+            }
+        }
+
+        // Determine the scale factor to pass to libjpeg for quick downscaling.
+        if (!scaledSize.isEmpty()) {
+            if (clipRect.isEmpty()) {
+                info->scale_denom =
+                    qMin(info->image_width / scaledSize.width(),
+                         info->image_height / scaledSize.height());
+            } else {
+                info->scale_denom =
+                    qMin(clipRect.width() / scaledSize.width(),
+                         clipRect.height() / scaledSize.height());
+            }
+            if (info->scale_denom < 2) {
+                info->scale_denom = 1;
+            } else if (info->scale_denom < 4) {
+                info->scale_denom = 2;
+            } else if (info->scale_denom < 8) {
+                info->scale_denom = 4;
+            } else {
+                info->scale_denom = 8;
+            }
+            info->scale_num = 1;
+            if (!clipRect.isEmpty()) {
+                // Correct the scale factor so that we clip accurately.
+                // It is recommended that the clip rectangle be aligned
+                // on an 8-pixel boundary for best performance.
+                while (info->scale_denom > 1 &&
+                       ((clipRect.x() % info->scale_denom) != 0 ||
+                        (clipRect.y() % info->scale_denom) != 0 ||
+                        (clipRect.width() % info->scale_denom) != 0 ||
+                        (clipRect.height() % info->scale_denom) != 0)) {
+                    info->scale_denom /= 2;
+                }
+            }
+        }
+
+        // If high quality not required, use fast decompression
+        if( quality < HIGH_QUALITY_THRESHOLD ) {
+            info->dct_method = JDCT_IFAST;
+            info->do_fancy_upsampling = FALSE;
+        }
+
+        (void) jpeg_calc_output_dimensions(info);
+
+        // Determine the clip region to extract.
+        QRect imageRect(0, 0, info->output_width, info->output_height);
+        QRect clip;
+        if (clipRect.isEmpty()) {
+            clip = imageRect;
+        } else if (info->scale_denom == info->scale_num) {
+            clip = clipRect.intersected(imageRect);
+        } else {
+            // The scale factor was corrected above to ensure that
+            // we don't miss pixels when we scale the clip rectangle.
+            clip = QRect(clipRect.x() / int(info->scale_denom),
+                         clipRect.y() / int(info->scale_denom),
+                         clipRect.width() / int(info->scale_denom),
+                         clipRect.height() / int(info->scale_denom));
+            clip = clip.intersected(imageRect);
+        }
+
+        // Allocate memory for the clipped QImage.
+        if (!ensureValidImage(outImage, info, clip.size()))
+            longjmp(err->setjmp_buffer, 1);
+
+        // Avoid memcpy() overhead if grayscale with no clipping.
+        bool quickGray = (info->output_components == 1 &&
+                          clip == imageRect);
+        if (!quickGray) {
+            // Ask the jpeg library to allocate a temporary row.
+            // The library will automatically delete it for us later.
+            // The libjpeg docs say we should do this before calling
+            // jpeg_start_decompress().  We can't use "new" here
+            // because we are inside the setjmp() block and an error
+            // in the jpeg input stream would cause a memory leak.
+            JSAMPARRAY rows = (info->mem->alloc_sarray)
+                              ((j_common_ptr)info, JPOOL_IMAGE,
+                               info->output_width * info->output_components, 1);
+
+            (void) jpeg_start_decompress(info);
+
+            while (info->output_scanline < info->output_height) {
+                int y = int(info->output_scanline) - clip.y();
+                if (y >= clip.height())
+                    break;      // We've read the entire clip region, so abort.
+
+                (void) jpeg_read_scanlines(info, rows, 1);
+
+                if (y < 0)
+                    continue;   // Haven't reached the starting line yet.
+
+                if (info->output_components == 3) {
+                    // Expand 24->32 bpp.
+                    uchar *in = rows[0] + clip.x() * 3;
+                    QRgb *out = (QRgb*)outImage->scanLine(y);
+                    for (int i = 0; i < clip.width(); ++i) {
+                        *out++ = qRgb(in[0], in[1], in[2]);
+                        in += 3;
+                    }
+                } else if (info->out_color_space == JCS_CMYK) {
+                    // Convert CMYK->RGB.
+                    uchar *in = rows[0] + clip.x() * 4;
+                    QRgb *out = (QRgb*)outImage->scanLine(y);
+                    for (int i = 0; i < clip.width(); ++i) {
+                        int k = in[3];
+                        *out++ = qRgb(k * in[0] / 255, k * in[1] / 255,
+                                      k * in[2] / 255);
+                        in += 4;
+                    }
+                } else if (info->output_components == 1) {
+                    // Grayscale.
+                    memcpy(outImage->scanLine(y),
+                           rows[0] + clip.x(), clip.width());
+                }
+            }
+        } else {
+            // Load unclipped grayscale data directly into the QImage.
+            (void) jpeg_start_decompress(info);
+            while (info->output_scanline < info->output_height) {
+                uchar *row = outImage->scanLine(info->output_scanline);
+                (void) jpeg_read_scanlines(info, &row, 1);
+            }
+        }
+
+        if (info->output_scanline == info->output_height)
+            (void) jpeg_finish_decompress(info);
+
+        if (info->density_unit == 1) {
+            outImage->setDotsPerMeterX(int(100. * info->X_density / 2.54));
+            outImage->setDotsPerMeterY(int(100. * info->Y_density / 2.54));
+        } else if (info->density_unit == 2) {
+            outImage->setDotsPerMeterX(int(100. * info->X_density));
+            outImage->setDotsPerMeterY(int(100. * info->Y_density));
+        }
+
+        if (scaledSize.isValid() && scaledSize != clip.size()) {
+            *outImage = outImage->scaled(scaledSize, Qt::IgnoreAspectRatio, quality >= HIGH_QUALITY_THRESHOLD ? Qt::SmoothTransformation : Qt::FastTransformation);
+        }
+
+        if (!scaledClipRect.isEmpty())
+            *outImage = outImage->copy(scaledClipRect);
+        return !outImage->isNull();
+    }
+    else
+        return false;
+}
+
+struct my_jpeg_destination_mgr : public jpeg_destination_mgr {
+    // Nothing dynamic - cannot rely on destruction over longjump
+    QIODevice *device;
+    JOCTET buffer[max_buf];
+
+public:
+    my_jpeg_destination_mgr(QIODevice *);
+};
+
+
+#if defined(Q_C_CALLBACKS)
+extern "C" {
+#endif
+
+static void qt_init_destination(j_compress_ptr)
+{
+}
+
+static boolean qt_empty_output_buffer(j_compress_ptr cinfo)
+{
+    my_jpeg_destination_mgr* dest = (my_jpeg_destination_mgr*)cinfo->dest;
+
+    int written = dest->device->write((char*)dest->buffer, max_buf);
+    if (written == -1)
+        (*cinfo->err->error_exit)((j_common_ptr)cinfo);
+
+    dest->next_output_byte = dest->buffer;
+    dest->free_in_buffer = max_buf;
+
+#if defined(Q_OS_UNIXWARE)
+    return B_TRUE;
+#else
+    return true;
+#endif
+}
+
+static void qt_term_destination(j_compress_ptr cinfo)
+{
+    my_jpeg_destination_mgr* dest = (my_jpeg_destination_mgr*)cinfo->dest;
+    qint64 n = max_buf - dest->free_in_buffer;
+
+    qint64 written = dest->device->write((char*)dest->buffer, n);
+    if (written == -1)
+        (*cinfo->err->error_exit)((j_common_ptr)cinfo);
+}
+
+#if defined(Q_C_CALLBACKS)
+}
+#endif
+
+inline my_jpeg_destination_mgr::my_jpeg_destination_mgr(QIODevice *device)
+{
+    jpeg_destination_mgr::init_destination = qt_init_destination;
+    jpeg_destination_mgr::empty_output_buffer = qt_empty_output_buffer;
+    jpeg_destination_mgr::term_destination = qt_term_destination;
+    this->device = device;
+    next_output_byte = buffer;
+    free_in_buffer = max_buf;
+}
+
+static bool can_write_format(QImage::Format fmt)
+{
+    switch (fmt) {
+    case QImage::Format_Mono:
+    case QImage::Format_MonoLSB:
+    case QImage::Format_Indexed8:
+    case QImage::Format_RGB888:
+    case QImage::Format_RGB32:
+    case QImage::Format_ARGB32:
+    case QImage::Format_ARGB32_Premultiplied:
+        return true;
+        break;
+    default:
+        break;
+    }
+    return false;
+}
+
+static bool write_jpeg_image(const QImage &sourceImage, QIODevice *device, int sourceQuality)
+{
+    bool success = false;
+    const QImage image = can_write_format(sourceImage.format()) ?
+                         sourceImage : sourceImage.convertToFormat(QImage::Format_RGB888);
+    const QVector<QRgb> cmap = image.colorTable();
+
+    struct jpeg_compress_struct cinfo;
+    JSAMPROW row_pointer[1];
+    row_pointer[0] = 0;
+
+    struct my_jpeg_destination_mgr *iod_dest = new my_jpeg_destination_mgr(device);
+    struct my_error_mgr jerr;
+
+    cinfo.err = jpeg_std_error(&jerr);
+    jerr.error_exit = my_error_exit;
+
+    if (!setjmp(jerr.setjmp_buffer)) {
+        // WARNING:
+        // this if loop is inside a setjmp/longjmp branch
+        // do not create C++ temporaries here because the destructor may never be called
+        // if you allocate memory, make sure that you can free it (row_pointer[0])
+        jpeg_create_compress(&cinfo);
+
+        cinfo.dest = iod_dest;
+
+        cinfo.image_width = image.width();
+        cinfo.image_height = image.height();
+
+        bool gray=false;
+        switch (image.format()) {
+        case QImage::Format_Mono:
+        case QImage::Format_MonoLSB:
+        case QImage::Format_Indexed8:
+            gray = true;
+            for (int i = image.colorCount(); gray && i--;) {
+                gray = gray & (qRed(cmap[i]) == qGreen(cmap[i]) &&
+                               qRed(cmap[i]) == qBlue(cmap[i]));
+            }
+            cinfo.input_components = gray ? 1 : 3;
+            cinfo.in_color_space = gray ? JCS_GRAYSCALE : JCS_RGB;
+            break;
+        default:
+            cinfo.input_components = 3;
+            cinfo.in_color_space = JCS_RGB;
+        }
+
+        jpeg_set_defaults(&cinfo);
+
+        qreal diffInch = qAbs(image.dotsPerMeterX()*2.54/100. - qRound(image.dotsPerMeterX()*2.54/100.))
+                         + qAbs(image.dotsPerMeterY()*2.54/100. - qRound(image.dotsPerMeterY()*2.54/100.));
+        qreal diffCm = (qAbs(image.dotsPerMeterX()/100. - qRound(image.dotsPerMeterX()/100.))
+                        + qAbs(image.dotsPerMeterY()/100. - qRound(image.dotsPerMeterY()/100.)))*2.54;
+        if (diffInch < diffCm) {
+            cinfo.density_unit = 1; // dots/inch
+            cinfo.X_density = qRound(image.dotsPerMeterX()*2.54/100.);
+            cinfo.Y_density = qRound(image.dotsPerMeterY()*2.54/100.);
+        } else {
+            cinfo.density_unit = 2; // dots/cm
+            cinfo.X_density = (image.dotsPerMeterX()+50) / 100;
+            cinfo.Y_density = (image.dotsPerMeterY()+50) / 100;
+        }
+
+
+        int quality = sourceQuality >= 0 ? qMin(sourceQuality,100) : 75;
+#if defined(Q_OS_UNIXWARE)
+        jpeg_set_quality(&cinfo, quality, B_TRUE /* limit to baseline-JPEG values */);
+        jpeg_start_compress(&cinfo, B_TRUE);
+#else
+        jpeg_set_quality(&cinfo, quality, true /* limit to baseline-JPEG values */);
+        jpeg_start_compress(&cinfo, true);
+#endif
+
+        row_pointer[0] = new uchar[cinfo.image_width*cinfo.input_components];
+        int w = cinfo.image_width;
+        while (cinfo.next_scanline < cinfo.image_height) {
+            uchar *row = row_pointer[0];
+            switch (image.format()) {
+            case QImage::Format_Mono:
+            case QImage::Format_MonoLSB:
+                if (gray) {
+                    const uchar* data = image.scanLine(cinfo.next_scanline);
+                    if (image.format() == QImage::Format_MonoLSB) {
+                        for (int i=0; i<w; i++) {
+                            bool bit = !!(*(data + (i >> 3)) & (1 << (i & 7)));
+                            row[i] = qRed(cmap[bit]);
+                        }
+                    } else {
+                        for (int i=0; i<w; i++) {
+                            bool bit = !!(*(data + (i >> 3)) & (1 << (7 -(i & 7))));
+                            row[i] = qRed(cmap[bit]);
+                        }
+                    }
+                } else {
+                    const uchar* data = image.scanLine(cinfo.next_scanline);
+                    if (image.format() == QImage::Format_MonoLSB) {
+                        for (int i=0; i<w; i++) {
+                            bool bit = !!(*(data + (i >> 3)) & (1 << (i & 7)));
+                            *row++ = qRed(cmap[bit]);
+                            *row++ = qGreen(cmap[bit]);
+                            *row++ = qBlue(cmap[bit]);
+                        }
+                    } else {
+                        for (int i=0; i<w; i++) {
+                            bool bit = !!(*(data + (i >> 3)) & (1 << (7 -(i & 7))));
+                            *row++ = qRed(cmap[bit]);
+                            *row++ = qGreen(cmap[bit]);
+                            *row++ = qBlue(cmap[bit]);
+                        }
+                    }
+                }
+                break;
+            case QImage::Format_Indexed8:
+                if (gray) {
+                    const uchar* pix = image.scanLine(cinfo.next_scanline);
+                    for (int i=0; i<w; i++) {
+                        *row = qRed(cmap[*pix]);
+                        ++row; ++pix;
+                    }
+                } else {
+                    const uchar* pix = image.scanLine(cinfo.next_scanline);
+                    for (int i=0; i<w; i++) {
+                        *row++ = qRed(cmap[*pix]);
+                        *row++ = qGreen(cmap[*pix]);
+                        *row++ = qBlue(cmap[*pix]);
+                        ++pix;
+                    }
+                }
+                break;
+            case QImage::Format_RGB888:
+                memcpy(row, image.scanLine(cinfo.next_scanline), w * 3);
+                break;
+            case QImage::Format_RGB32:
+            case QImage::Format_ARGB32:
+            case QImage::Format_ARGB32_Premultiplied: {
+                QRgb* rgb = (QRgb*)image.scanLine(cinfo.next_scanline);
+                for (int i=0; i<w; i++) {
+                    *row++ = qRed(*rgb);
+                    *row++ = qGreen(*rgb);
+                    *row++ = qBlue(*rgb);
+                    ++rgb;
+                }
+                break;
+            }
+            default:
+                qWarning("QJpegHandler: unable to write image of format %i",
+                         image.format());
+                break;
+            }
+            jpeg_write_scanlines(&cinfo, row_pointer, 1);
+        }
+
+        jpeg_finish_compress(&cinfo);
+        jpeg_destroy_compress(&cinfo);
+        success = true;
+    } else {
+        jpeg_destroy_compress(&cinfo);
+        success = false;
+    }
+
+    delete iod_dest;
+    delete [] row_pointer[0];
+    return success;
+}
+
+class QJpegHandlerPrivate
+{
+public:
+    enum State {
+        Ready,
+        ReadHeader,
+        Error
+    };
+
+    QJpegHandlerPrivate(QJpegHandler *qq)
+        : quality(75), iod_src(0), state(Ready), q(qq)
+    {}
+
+    ~QJpegHandlerPrivate()
+    {
+        if(iod_src)
+        {
+            jpeg_destroy_decompress(&info);
+            delete iod_src;
+            iod_src = 0;
+        }
+    }
+
+    bool readJpegHeader(QIODevice*);
+    bool read(QImage *image);
+
+    int quality;
+    QVariant size;
+    QImage::Format format;
+    QSize scaledSize;
+    QRect scaledClipRect;
+    QRect clipRect;
+    struct jpeg_decompress_struct info;
+    struct my_jpeg_source_mgr * iod_src;
+    struct my_error_mgr err;
+
+    State state;
+
+    QJpegHandler *q;
+};
+
+/*!
+    \internal
+*/
+bool QJpegHandlerPrivate::readJpegHeader(QIODevice *device)
+{
+    if(state == Ready)
+    {
+        state = Error;
+        iod_src = new my_jpeg_source_mgr(device);
+
+        jpeg_create_decompress(&info);
+        info.src = iod_src;
+        info.err = jpeg_std_error(&err);
+        err.error_exit = my_error_exit;
+
+        if (!setjmp(err.setjmp_buffer)) {
+    #if defined(Q_OS_UNIXWARE)
+            (void) jpeg_read_header(&info, B_TRUE);
+    #else
+            (void) jpeg_read_header(&info, true);
+    #endif
+
+            int width = 0;
+            int height = 0;
+            read_jpeg_size(width, height, &info);
+            size = QSize(width, height);
+
+            format = QImage::Format_Invalid;
+            read_jpeg_format(format, &info);
+            state = ReadHeader;
+            return true;
+        }
+        else
+        {
+            return false;
+        }
+    }
+    else if(state == Error)
+        return false;
+    return true;
+}
+
+bool QJpegHandlerPrivate::read(QImage *image)
+{
+    if(state == Ready)
+        readJpegHeader(q->device());
+
+    if(state == ReadHeader)
+    {
+        bool success = read_jpeg_image(image, scaledSize, scaledClipRect, clipRect, quality,  &info, &err);
+        state = success ? Ready : Error;
+        return success;
+    }
+
+    return false;
+
+}
+
+QJpegHandler::QJpegHandler()
+    : d(new QJpegHandlerPrivate(this))
+{
+}
+
+QJpegHandler::~QJpegHandler()
+{
+    delete d;
+}
+
+bool QJpegHandler::canRead() const
+{
+    if(d->state == QJpegHandlerPrivate::Ready && !canRead(device()))
+        return false;
+
+    if (d->state != QJpegHandlerPrivate::Error) {
+        setFormat("jpeg");
+        return true;
+    }
+
+    return false;
+}
+
+bool QJpegHandler::canRead(QIODevice *device)
+{
+    if (!device) {
+        qWarning("QJpegHandler::canRead() called with no device");
+        return false;
+    }
+
+    char buffer[2];
+    if (device->peek(buffer, 2) != 2)
+        return false;
+    return uchar(buffer[0]) == 0xff && uchar(buffer[1]) == 0xd8;
+}
+
+bool QJpegHandler::read(QImage *image)
+{
+    if (!canRead())
+        return false;
+    return d->read(image);
+}
+
+bool QJpegHandler::write(const QImage &image)
+{
+    return write_jpeg_image(image, device(), d->quality);
+}
+
+bool QJpegHandler::supportsOption(ImageOption option) const
+{
+    return option == Quality
+        || option == ScaledSize
+        || option == ScaledClipRect
+        || option == ClipRect
+        || option == Size
+        || option == ImageFormat;
+}
+
+QVariant QJpegHandler::option(ImageOption option) const
+{
+    switch(option) {
+    case Quality:
+        return d->quality;
+    case ScaledSize:
+        return d->scaledSize;
+    case ScaledClipRect:
+        return d->scaledClipRect;
+    case ClipRect:
+        return d->clipRect;
+    case Size:
+        d->readJpegHeader(device());
+        return d->size;
+    case ImageFormat:
+        d->readJpegHeader(device());
+        return d->format;
+    default:
+        return QVariant();
+    }
+}
+
+void QJpegHandler::setOption(ImageOption option, const QVariant &value)
+{
+    switch(option) {
+    case Quality:
+        d->quality = value.toInt();
+        break;
+    case ScaledSize:
+        d->scaledSize = value.toSize();
+        break;
+    case ScaledClipRect:
+        d->scaledClipRect = value.toRect();
+        break;
+    case ClipRect:
+        d->clipRect = value.toRect();
+        break;
+    default:
+        break;
+    }
+}
+
+QByteArray QJpegHandler::name() const
+{
+    return "jpeg";
+}
+
+
+
+
+QT_END_NAMESPACE