qimagewriter.cpp

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#include "qimagewriter.h"

#include <qbytearray.h>
#include <qfile.h>
#include <qfileinfo.h>
#include <qimageiohandler.h>
#include <qset.h>
#include <qvariant.h>

// factory loader
#include <qcoreapplication.h>
#include <private/qfactoryloader_p.h>

// image handlers
#include <private/qbmphandler_p.h>
#include <private/qppmhandler_p.h>
#include <private/qxbmhandler_p.h>
#include <private/qxpmhandler_p.h>
#ifndef QT_NO_IMAGEFORMAT_PNG
#include <private/qpnghandler_p.h>
#endif
#ifndef QT_NO_IMAGEFORMAT_JPEG
#include <private/qjpeghandler_p.h>
#endif
#ifndef QT_NO_IMAGEFORMAT_MNG
#include <private/qmnghandler_p.h>
#endif
#ifndef QT_NO_IMAGEFORMAT_TIFF
#include <private/qtiffhandler_p.h>
#endif
#ifdef QT_BUILTIN_GIF_READER
#include <private/qgifhandler_p.h>
#endif

QT_BEGIN_NAMESPACE

#ifndef QT_NO_LIBRARY
Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loader,
                          (QImageIOHandlerFactoryInterface_iid, QLatin1String("/imageformats")))
#endif

static QImageIOHandler *createWriteHandlerHelper(QIODevice *device,
    const QByteArray &format)
{
    QByteArray form = format.toLower();
    QByteArray suffix;
    QImageIOHandler *handler = 0;

#ifndef QT_NO_LIBRARY
    // check if any plugins can write the image
    QFactoryLoader *l = loader();
    QStringList keys = l->keys();
    int suffixPluginIndex = -1;
#endif

    if (device && format.isEmpty()) {
        // if there's no format, see if \a device is a file, and if so, find
        // the file suffix and find support for that format among our plugins.
        // this allows plugins to override our built-in handlers.
        if (QFile *file = qobject_cast<QFile *>(device)) {
            if (!(suffix = QFileInfo(file->fileName()).suffix().toLower().toLatin1()).isEmpty()) {
#ifndef QT_NO_LIBRARY
                int index = keys.indexOf(QString::fromLatin1(suffix));
                if (index != -1)
                    suffixPluginIndex = index;
#endif
            }
        }
    }

    QByteArray testFormat = !form.isEmpty() ? form : suffix;

#ifndef QT_NO_LIBRARY
    if (suffixPluginIndex != -1) {
        // when format is missing, check if we can find a plugin for the
        // suffix.
        QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(QString::fromLatin1(suffix)));
        if (plugin && (plugin->capabilities(device, suffix) & QImageIOPlugin::CanWrite))
            handler = plugin->create(device, suffix);
    }
#endif // QT_NO_LIBRARY

    // check if any built-in handlers can write the image
    if (!handler && !testFormat.isEmpty()) {
        if (false) {
#ifndef QT_NO_IMAGEFORMAT_PNG
        } else if (testFormat == "png") {
            handler = new QPngHandler;
#endif
#ifndef QT_NO_IMAGEFORMAT_JPEG
        } else if (testFormat == "jpg" || testFormat == "jpeg") {
            handler = new QJpegHandler;
#endif
#ifndef QT_NO_IMAGEFORMAT_MNG
        } else if (testFormat == "mng") {
            handler = new QMngHandler;
#endif
#ifndef QT_NO_IMAGEFORMAT_TIFF
        } else if (testFormat == "tif" || testFormat == "tiff") {
            handler = new QTiffHandler;
#endif
#ifdef QT_BUILTIN_GIF_READER
        } else if (testFormat == "gif") {
            handler = new QGifHandler;
#endif
#ifndef QT_NO_IMAGEFORMAT_BMP
        } else if (testFormat == "bmp") {
            handler = new QBmpHandler;
#endif
#ifndef QT_NO_IMAGEFORMAT_XPM
        } else if (testFormat == "xpm") {
            handler = new QXpmHandler;
#endif
#ifndef QT_NO_IMAGEFORMAT_XBM
        } else if (testFormat == "xbm") {
            handler = new QXbmHandler;
            handler->setOption(QImageIOHandler::SubType, testFormat);
#endif
#ifndef QT_NO_IMAGEFORMAT_PPM
        } else if (testFormat == "pbm" || testFormat == "pbmraw" || testFormat == "pgm"
                 || testFormat == "pgmraw" || testFormat == "ppm" || testFormat == "ppmraw") {
            handler = new QPpmHandler;
            handler->setOption(QImageIOHandler::SubType, testFormat);
#endif
        }
    }

#ifndef QT_NO_LIBRARY
    if (!testFormat.isEmpty()) {
        for (int i = 0; i < keys.size(); ++i) {
            QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(keys.at(i)));
            if (plugin && (plugin->capabilities(device, testFormat) & QImageIOPlugin::CanWrite)) {
                delete handler;
                handler = plugin->create(device, testFormat);
                break;
            }
        }
    }
#endif // QT_NO_LIBRARY

    if (!handler)
        return 0;

    handler->setDevice(device);
    if (!testFormat.isEmpty())
        handler->setFormat(testFormat);
    return handler;
}

class QImageWriterPrivate
{
public:
    QImageWriterPrivate(QImageWriter *qq);

    // device
    QByteArray format;
    QIODevice *device;
    bool deleteDevice;
    QImageIOHandler *handler;

    // image options
    int quality;
    int compression;
    float gamma;
    QString description;
    QString text;

    // error
    QImageWriter::ImageWriterError imageWriterError;
    QString errorString;

    QImageWriter *q;
};

QImageWriterPrivate::QImageWriterPrivate(QImageWriter *qq)
{
    device = 0;
    deleteDevice = false;
    handler = 0;
    quality = -1;
    compression = 0;
    gamma = 0.0;
    imageWriterError = QImageWriter::UnknownError;
    errorString = QT_TRANSLATE_NOOP(QImageWriter, QLatin1String("Unknown error"));

    q = qq;
}

QImageWriter::QImageWriter()
    : d(new QImageWriterPrivate(this))
{
}

QImageWriter::QImageWriter(QIODevice *device, const QByteArray &format)
    : d(new QImageWriterPrivate(this))
{
    d->device = device;
    d->format = format;
}

QImageWriter::QImageWriter(const QString &fileName, const QByteArray &format)
    : d(new QImageWriterPrivate(this))
{
    QFile *file = new QFile(fileName);
    d->device = file;
    d->deleteDevice = true;
    d->format = format;
}

QImageWriter::~QImageWriter()
{
    if (d->deleteDevice)
        delete d->device;
    delete d->handler;
    delete d;
}

void QImageWriter::setFormat(const QByteArray &format)
{
    d->format = format;
}

QByteArray QImageWriter::format() const
{
    return d->format;
}

void QImageWriter::setDevice(QIODevice *device)
{
    if (d->device && d->deleteDevice)
        delete d->device;

    d->device = device;
    d->deleteDevice = false;
    delete d->handler;
    d->handler = 0;
}

QIODevice *QImageWriter::device() const
{
    return d->device;
}

void QImageWriter::setFileName(const QString &fileName)
{
    setDevice(new QFile(fileName));
    d->deleteDevice = true;
}

QString QImageWriter::fileName() const
{
    QFile *file = qobject_cast<QFile *>(d->device);
    return file ? file->fileName() : QString();
}

void QImageWriter::setQuality(int quality)
{
    d->quality = quality;
}

int QImageWriter::quality() const
{
    return d->quality;
}

void QImageWriter::setCompression(int compression)
{
    d->compression = compression;
}

int QImageWriter::compression() const
{
    return d->compression;
}

void QImageWriter::setGamma(float gamma)
{
    d->gamma = gamma;
}

float QImageWriter::gamma() const
{
    return d->gamma;
}

void QImageWriter::setDescription(const QString &description)
{
    d->description = description;
}

QString QImageWriter::description() const
{
    return d->description;
}

void QImageWriter::setText(const QString &key, const QString &text)
{
    if (!d->description.isEmpty())
        d->description += QLatin1String("\n\n");
    d->description += key.simplified() + QLatin1String(": ") + text.simplified();
}

bool QImageWriter::canWrite() const
{
    if (d->device && !d->handler && (d->handler = createWriteHandlerHelper(d->device, d->format)) == 0) {
        d->imageWriterError = QImageWriter::UnsupportedFormatError;
        d->errorString = QT_TRANSLATE_NOOP(QImageWriter,
                                           QLatin1String("Unsupported image format"));
        return false;
    }
    if (d->device && !d->device->isOpen())
        d->device->open(QIODevice::WriteOnly);
    if (!d->device || !d->device->isWritable()) {
        d->imageWriterError = QImageWriter::DeviceError;
        d->errorString = QT_TRANSLATE_NOOP(QImageWriter,
                                           QLatin1String("Device not writable"));
        return false;
    }
    return true;
}

bool QImageWriter::write(const QImage &image)
{
    if (!canWrite())
        return false;

    if (d->handler->supportsOption(QImageIOHandler::Quality))
        d->handler->setOption(QImageIOHandler::Quality, d->quality);
    if (d->handler->supportsOption(QImageIOHandler::CompressionRatio))
        d->handler->setOption(QImageIOHandler::CompressionRatio, d->compression);
    if (d->handler->supportsOption(QImageIOHandler::Gamma))
        d->handler->setOption(QImageIOHandler::Gamma, d->gamma);
    if (!d->description.isEmpty() && d->handler->supportsOption(QImageIOHandler::Description))
        d->handler->setOption(QImageIOHandler::Description, d->description);

    if (!d->handler->write(image))
        return false;
    if (QFile *file = qobject_cast<QFile *>(d->device))
        file->flush();
    return true;
}

QImageWriter::ImageWriterError QImageWriter::error() const
{
    return d->imageWriterError;
}

QString QImageWriter::errorString() const
{
    return d->errorString;
}

bool QImageWriter::supportsOption(QImageIOHandler::ImageOption option) const
{
    if (!d->handler && (d->handler = createWriteHandlerHelper(d->device, d->format)) == 0) {
        d->imageWriterError = QImageWriter::UnsupportedFormatError;
        d->errorString = QT_TRANSLATE_NOOP(QImageWriter,
                                           QLatin1String("Unsupported image format"));
        return false;
    }

    return d->handler->supportsOption(option);
}

QList<QByteArray> QImageWriter::supportedImageFormats()
{
    QSet<QByteArray> formats;
    formats << "bmp";
#ifndef QT_NO_IMAGEFORMAT_PPM
    formats << "ppm";
#endif
#ifndef QT_NO_IMAGEFORMAT_XBM
    formats << "xbm";
#endif
#ifndef QT_NO_IMAGEFORMAT_XPM
    formats << "xpm";
#endif
#ifndef QT_NO_IMAGEFORMAT_PNG
    formats << "png";
#endif
#ifndef QT_NO_IMAGEFORMAT_JPEG
    formats << "jpg" << "jpeg";
#endif
#ifndef QT_NO_IMAGEFORMAT_MNG
    formats << "mng";
#endif
#ifndef QT_NO_IMAGEFORMAT_TIFF
    formats << "tif" << "tiff";
#endif
#ifdef QT_BUILTIN_GIF_READER
    formats << "gif";
#endif

#ifndef QT_NO_LIBRARY
    QFactoryLoader *l = loader();
    QStringList keys = l->keys();
    for (int i = 0; i < keys.count(); ++i) {
        QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(keys.at(i)));
        if (plugin && (plugin->capabilities(0, keys.at(i).toLatin1()) & QImageIOPlugin::CanWrite) != 0)
            formats << keys.at(i).toLatin1();
    }
#endif // QT_NO_LIBRARY

    QList<QByteArray> sortedFormats;
    for (QSet<QByteArray>::ConstIterator it = formats.constBegin(); it != formats.constEnd(); ++it)
        sortedFormats << *it;

    qSort(sortedFormats);
    return sortedFormats;
}

QT_END_NAMESPACE