Avoid code duplication in QImage{Reader,Writer}

Extract code related to supportedImageFormats() and
supportedMimeTypes() into QImageReaderWriterHelpers
namespace.

Change-Id: If0f56682072859be1b6f07afd7737431325827fc
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>

5 files changed, 299 insertions, 201 deletions

diff --git a/src/gui/image/image.pri b/src/gui/image/image.pri
index 76aba944b2..b4942f06d4 100644
--- a/src/gui/image/image.pri
+++ b/src/gui/image/image.pri
@@ -9,6 +9,7 @@ HEADERS += \
         image/qimage_p.h \
         image/qimageiohandler.h \
         image/qimagereader.h \
+        image/qimagereaderwriterhelpers_p.h \
         image/qimagewriter.h \
         image/qpaintengine_pic_p.h \
         image/qpicture.h \
@@ -33,6 +34,7 @@ SOURCES += \
         image/qimage_conversions.cpp \
         image/qimageiohandler.cpp \
         image/qimagereader.cpp \
+        image/qimagereaderwriterhelpers.cpp \
         image/qimagewriter.cpp \
         image/qpaintengine_pic.cpp \
         image/qpicture.cpp \
diff --git a/src/gui/image/qimagereader.cpp b/src/gui/image/qimagereader.cpp
index 7086e102ea..a2686bd238 100644
--- a/src/gui/image/qimagereader.cpp
+++ b/src/gui/image/qimagereader.cpp
@@ -164,73 +164,13 @@
 #include <private/qpnghandler_p.h>
 #endif
 
+#include <private/qimagereaderwriterhelpers_p.h>
+
 #include <algorithm>
 
 QT_BEGIN_NAMESPACE
 
-#ifndef QT_NO_IMAGEFORMATPLUGIN
-Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loader,
-                          (QImageIOHandlerFactoryInterface_iid, QLatin1String("/imageformats")))
-#endif
-
-enum _qt_BuiltInFormatType {
-#ifndef QT_NO_IMAGEFORMAT_PNG
-    _qt_PngFormat,
-#endif
-#ifndef QT_NO_IMAGEFORMAT_BMP
-    _qt_BmpFormat,
-#endif
-#ifndef QT_NO_IMAGEFORMAT_PPM
-    _qt_PpmFormat,
-    _qt_PgmFormat,
-    _qt_PbmFormat,
-#endif
-#ifndef QT_NO_IMAGEFORMAT_XBM
-    _qt_XbmFormat,
-#endif
-#ifndef QT_NO_IMAGEFORMAT_XPM
-    _qt_XpmFormat,
-#endif
-    _qt_NumFormats,
-    _qt_NoFormat = -1
-};
-
-#if !defined(QT_NO_IMAGEFORMAT_PPM)
-# define MAX_MT_SIZE 20
-#elif !defined(QT_NO_IMAGEFORMAT_XBM) || !defined(QT_NO_IMAGEFORMAT_XPM)
-#  define MAX_MT_SIZE 10
-#else
-#  define MAX_MT_SIZE 4
-#endif
-
-struct _qt_BuiltInFormatStruct
-{
-    char extension[4];
-    char mimeType[MAX_MT_SIZE];
-};
-
-#undef MAX_MT_SIZE
-
-static const _qt_BuiltInFormatStruct _qt_BuiltInFormats[] = {
-#ifndef QT_NO_IMAGEFORMAT_PNG
-    {"png", "png"},
-#endif
-#ifndef QT_NO_IMAGEFORMAT_BMP
-    {"bmp", "bmp"},
-#endif
-#ifndef QT_NO_IMAGEFORMAT_PPM
-    {"ppm", "x-portable-pixmap"},
-    {"pgm", "x-portable-graymap"},
-    {"pbm", "x-portable-bitmap"},
-#endif
-#ifndef QT_NO_IMAGEFORMAT_XBM
-    {"xbm", "x-xbitmap"},
-#endif
-#ifndef QT_NO_IMAGEFORMAT_XPM
-    {"xpm", "x-xpixmap"},
-#endif
-};
-Q_STATIC_ASSERT(_qt_NumFormats == sizeof _qt_BuiltInFormats / sizeof *_qt_BuiltInFormats);
+using namespace QImageReaderWriterHelpers;
 
 static QImageIOHandler *createReadHandlerHelper(QIODevice *device,
                                                 const QByteArray &format,
@@ -251,7 +191,7 @@ static QImageIOHandler *createReadHandlerHelper(QIODevice *device,
     typedef QMultiMap<int, QString> PluginKeyMap;
 
     // check if we have plugins that support the image format
-    QFactoryLoader *l = loader();
+    auto l = QImageReaderWriterHelpers::pluginLoader();
     const PluginKeyMap keyMap = l->keyMap();
 
 #ifdef QIMAGEREADER_DEBUG
@@ -1565,16 +1505,6 @@ QByteArray QImageReader::imageFormat(QIODevice *device)
     return format;
 }
 
-#ifndef QT_NO_IMAGEFORMATPLUGIN
-void supportedImageHandlerFormats(QFactoryLoader *loader,
-                                  QImageIOPlugin::Capability cap,
-                                  QList<QByteArray> *result);
-
-void supportedImageHandlerMimeTypes(QFactoryLoader *loader,
-                                  QImageIOPlugin::Capability cap,
-                                  QList<QByteArray> *result);
-#endif
-
 /*!
     Returns the list of image formats supported by QImageReader.
 
@@ -1605,18 +1535,7 @@ void supportedImageHandlerMimeTypes(QFactoryLoader *loader,
 
 QList<QByteArray> QImageReader::supportedImageFormats()
 {
-    QList<QByteArray> formats;
-    formats.reserve(_qt_NumFormats);
-    for (int i = 0; i < _qt_NumFormats; ++i)
-        formats << _qt_BuiltInFormats[i].extension;
-
-#ifndef QT_NO_IMAGEFORMATPLUGIN
-    supportedImageHandlerFormats(loader(), QImageIOPlugin::CanRead, &formats);
-#endif // QT_NO_IMAGEFORMATPLUGIN
-
-    std::sort(formats.begin(), formats.end());
-    formats.erase(std::unique(formats.begin(), formats.end()), formats.end());
-    return formats;
+    return QImageReaderWriterHelpers::supportedImageFormats(QImageReaderWriterHelpers::CanRead);
 }
 
 /*!
@@ -1630,18 +1549,7 @@ QList<QByteArray> QImageReader::supportedImageFormats()
 
 QList<QByteArray> QImageReader::supportedMimeTypes()
 {
-    QList<QByteArray> mimeTypes;
-    mimeTypes.reserve(_qt_NumFormats);
-    for (const auto &fmt : _qt_BuiltInFormats)
-        mimeTypes.append(QByteArrayLiteral("image/") + fmt.mimeType);
-
-#ifndef QT_NO_IMAGEFORMATPLUGIN
-    supportedImageHandlerMimeTypes(loader(), QImageIOPlugin::CanRead, &mimeTypes);
-#endif // QT_NO_IMAGEFORMATPLUGIN
-
-    std::sort(mimeTypes.begin(), mimeTypes.end());
-    mimeTypes.erase(std::unique(mimeTypes.begin(), mimeTypes.end()), mimeTypes.end());
-    return mimeTypes;
+    return QImageReaderWriterHelpers::supportedMimeTypes(QImageReaderWriterHelpers::CanRead);
 }
 
 QT_END_NAMESPACE
diff --git a/src/gui/image/qimagereaderwriterhelpers.cpp b/src/gui/image/qimagereaderwriterhelpers.cpp
new file mode 100644
index 0000000000..6481f0e603
--- /dev/null
+++ b/src/gui/image/qimagereaderwriterhelpers.cpp
@@ -0,0 +1,148 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "private/qimagereaderwriterhelpers_p.h"
+
+#include <qjsonarray.h>
+#include <qmutex.h>
+#include <private/qfactoryloader_p.h>
+
+QT_BEGIN_NAMESPACE
+
+namespace QImageReaderWriterHelpers {
+
+#ifndef QT_NO_IMAGEFORMATPLUGIN
+
+Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loader,
+                          (QImageIOHandlerFactoryInterface_iid, QLatin1String("/imageformats")))
+Q_GLOBAL_STATIC(QMutex, loaderMutex)
+
+static void appendImagePluginFormats(QFactoryLoader *loader,
+                                     QImageIOPlugin::Capability cap,
+                                     QList<QByteArray> *result)
+{
+    typedef QMultiMap<int, QString> PluginKeyMap;
+    typedef PluginKeyMap::const_iterator PluginKeyMapConstIterator;
+
+    const PluginKeyMap keyMap = loader->keyMap();
+    const PluginKeyMapConstIterator cend = keyMap.constEnd();
+    int i = -1;
+    QImageIOPlugin *plugin = 0;
+    result->reserve(result->size() + keyMap.size());
+    for (PluginKeyMapConstIterator it = keyMap.constBegin(); it != cend; ++it) {
+        if (it.key() != i) {
+            i = it.key();
+            plugin = qobject_cast<QImageIOPlugin *>(loader->instance(i));
+        }
+        const QByteArray key = it.value().toLatin1();
+        if (plugin && (plugin->capabilities(0, key) & cap) != 0)
+            result->append(key);
+    }
+}
+
+static void appendImagePluginMimeTypes(QFactoryLoader *loader,
+                                       QImageIOPlugin::Capability cap,
+                                       QList<QByteArray> *result)
+{
+    QList<QJsonObject> metaDataList = loader->metaData();
+
+    const int pluginCount = metaDataList.size();
+    for (int i = 0; i < pluginCount; ++i) {
+        const QJsonObject metaData = metaDataList.at(i).value(QLatin1String("MetaData")).toObject();
+        const QJsonArray keys = metaData.value(QLatin1String("Keys")).toArray();
+        const QJsonArray mimeTypes = metaData.value(QLatin1String("MimeTypes")).toArray();
+        QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(loader->instance(i));
+        const int keyCount = keys.size();
+        for (int k = 0; k < keyCount; ++k) {
+            if (plugin && (plugin->capabilities(0, keys.at(k).toString().toLatin1()) & cap) != 0)
+                result->append(mimeTypes.at(k).toString().toLatin1());
+        }
+    }
+}
+
+QSharedPointer<QFactoryLoader> pluginLoader()
+{
+    loaderMutex()->lock();
+    return QSharedPointer<QFactoryLoader>(loader(), [](QFactoryLoader *) {
+        loaderMutex()->unlock();
+    });
+}
+
+static inline QImageIOPlugin::Capability pluginCapability(Capability cap)
+{
+    return cap == CanRead ? QImageIOPlugin::CanRead : QImageIOPlugin::CanWrite;
+}
+
+#endif // QT_NO_IMAGEFORMATPLUGIN
+
+QList<QByteArray> supportedImageFormats(Capability cap)
+{
+    QList<QByteArray> formats;
+    formats.reserve(_qt_NumFormats);
+    for (int i = 0; i < _qt_NumFormats; ++i)
+        formats << _qt_BuiltInFormats[i].extension;
+
+#ifndef QT_NO_IMAGEFORMATPLUGIN
+    appendImagePluginFormats(loader(), pluginCapability(cap), &formats);
+#endif // QT_NO_IMAGEFORMATPLUGIN
+
+    std::sort(formats.begin(), formats.end());
+    formats.erase(std::unique(formats.begin(), formats.end()), formats.end());
+    return formats;
+}
+
+QList<QByteArray> supportedMimeTypes(Capability cap)
+{
+    QList<QByteArray> mimeTypes;
+    mimeTypes.reserve(_qt_NumFormats);
+    for (const auto &fmt : _qt_BuiltInFormats)
+        mimeTypes.append(QByteArrayLiteral("image/") + fmt.mimeType);
+
+#ifndef QT_NO_IMAGEFORMATPLUGIN
+    appendImagePluginMimeTypes(loader(), pluginCapability(cap), &mimeTypes);
+#endif // QT_NO_IMAGEFORMATPLUGIN
+
+    std::sort(mimeTypes.begin(), mimeTypes.end());
+    mimeTypes.erase(std::unique(mimeTypes.begin(), mimeTypes.end()), mimeTypes.end());
+    return mimeTypes;
+}
+
+} // QImageReaderWriterHelpers
+
+QT_END_NAMESPACE
diff --git a/src/gui/image/qimagereaderwriterhelpers_p.h b/src/gui/image/qimagereaderwriterhelpers_p.h
new file mode 100644
index 0000000000..358ae9be89
--- /dev/null
+++ b/src/gui/image/qimagereaderwriterhelpers_p.h
@@ -0,0 +1,138 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QIMAGEREADERWRITERHELPERS_P_H
+#define QIMAGEREADERWRITERHELPERS_P_H
+
+#include <QtGui/private/qtguiglobal_p.h>
+#include <qsharedpointer.h>
+#include "qimageiohandler.h"
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API. It exists purely as an
+// implementation detail. This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+QT_BEGIN_NAMESPACE
+
+class QFactoryLoader;
+
+namespace QImageReaderWriterHelpers {
+
+enum _qt_BuiltInFormatType {
+#ifndef QT_NO_IMAGEFORMAT_PNG
+    _qt_PngFormat,
+#endif
+#ifndef QT_NO_IMAGEFORMAT_BMP
+    _qt_BmpFormat,
+#endif
+#ifndef QT_NO_IMAGEFORMAT_PPM
+    _qt_PpmFormat,
+    _qt_PgmFormat,
+    _qt_PbmFormat,
+#endif
+#ifndef QT_NO_IMAGEFORMAT_XBM
+    _qt_XbmFormat,
+#endif
+#ifndef QT_NO_IMAGEFORMAT_XPM
+    _qt_XpmFormat,
+#endif
+    _qt_NumFormats,
+    _qt_NoFormat = -1
+};
+
+#if !defined(QT_NO_IMAGEFORMAT_PPM)
+# define MAX_MT_SIZE 20
+#elif !defined(QT_NO_IMAGEFORMAT_XBM) || !defined(QT_NO_IMAGEFORMAT_XPM)
+#  define MAX_MT_SIZE 10
+#else
+#  define MAX_MT_SIZE 4
+#endif
+
+struct _qt_BuiltInFormatStruct
+{
+    char extension[4];
+    char mimeType[MAX_MT_SIZE];
+};
+
+#undef MAX_MT_SIZE
+
+static const _qt_BuiltInFormatStruct _qt_BuiltInFormats[] = {
+#ifndef QT_NO_IMAGEFORMAT_PNG
+    {"png", "png"},
+#endif
+#ifndef QT_NO_IMAGEFORMAT_BMP
+    {"bmp", "bmp"},
+#endif
+#ifndef QT_NO_IMAGEFORMAT_PPM
+    {"ppm", "x-portable-pixmap"},
+    {"pgm", "x-portable-graymap"},
+    {"pbm", "x-portable-bitmap"},
+#endif
+#ifndef QT_NO_IMAGEFORMAT_XBM
+    {"xbm", "x-xbitmap"},
+#endif
+#ifndef QT_NO_IMAGEFORMAT_XPM
+    {"xpm", "x-xpixmap"},
+#endif
+};
+Q_STATIC_ASSERT(_qt_NumFormats == sizeof _qt_BuiltInFormats / sizeof *_qt_BuiltInFormats);
+
+#ifndef QT_NO_IMAGEFORMATPLUGIN
+QSharedPointer<QFactoryLoader> pluginLoader();
+#endif
+
+enum Capability {
+    CanRead,
+    CanWrite
+};
+QList<QByteArray> supportedImageFormats(Capability cap);
+QList<QByteArray> supportedMimeTypes(Capability cap);
+
+}
+
+QT_END_NAMESPACE
+
+#endif // QIMAGEREADERWRITERHELPERS_P_H
diff --git a/src/gui/image/qimagewriter.cpp b/src/gui/image/qimagewriter.cpp
index a39d204677..fd036da604 100644
--- a/src/gui/image/qimagewriter.cpp
+++ b/src/gui/image/qimagewriter.cpp
@@ -102,7 +102,6 @@
 #include <qfileinfo.h>
 #include <qimage.h>
 #include <qimageiohandler.h>
-#include <qjsonarray.h>
 #include <qset.h>
 #include <qvariant.h>
 
@@ -119,15 +118,12 @@
 #include <private/qpnghandler_p.h>
 #endif
 
+#include <private/qimagereaderwriterhelpers_p.h>
+
 #include <algorithm>
 
 QT_BEGIN_NAMESPACE
 
-#ifndef QT_NO_IMAGEFORMATPLUGIN
-Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loader,
-                          (QImageIOHandlerFactoryInterface_iid, QLatin1String("/imageformats")))
-#endif
-
 static QImageIOHandler *createWriteHandlerHelper(QIODevice *device,
     const QByteArray &format)
 {
@@ -139,7 +135,7 @@ static QImageIOHandler *createWriteHandlerHelper(QIODevice *device,
     typedef QMultiMap<int, QString> PluginKeyMap;
 
     // check if any plugins can write the image
-    QFactoryLoader *l = loader();
+    auto l = QImageReaderWriterHelpers::pluginLoader();
     const PluginKeyMap keyMap = l->keyMap();
     int suffixPluginIndex = -1;
 #endif
@@ -824,52 +820,6 @@ bool QImageWriter::supportsOption(QImageIOHandler::ImageOption option) const
     return d->handler->supportsOption(option);
 }
 
-
-#ifndef QT_NO_IMAGEFORMATPLUGIN
-void supportedImageHandlerFormats(QFactoryLoader *loader,
-                                  QImageIOPlugin::Capability cap,
-                                  QList<QByteArray> *result)
-{
-    typedef QMultiMap<int, QString> PluginKeyMap;
-    typedef PluginKeyMap::const_iterator PluginKeyMapConstIterator;
-
-    const PluginKeyMap keyMap = loader->keyMap();
-    const PluginKeyMapConstIterator cend = keyMap.constEnd();
-    int i = -1;
-    QImageIOPlugin *plugin = 0;
-    result->reserve(result->size() + keyMap.size());
-    for (PluginKeyMapConstIterator it = keyMap.constBegin(); it != cend; ++it) {
-        if (it.key() != i) {
-            i = it.key();
-            plugin = qobject_cast<QImageIOPlugin *>(loader->instance(i));
-        }
-        const QByteArray key = it.value().toLatin1();
-        if (plugin && (plugin->capabilities(0, key) & cap) != 0)
-            result->append(key);
-    }
-}
-
-void supportedImageHandlerMimeTypes(QFactoryLoader *loader,
-                                    QImageIOPlugin::Capability cap,
-                                    QList<QByteArray> *result)
-{
-    QList<QJsonObject> metaDataList = loader->metaData();
-
-    const int pluginCount = metaDataList.size();
-    for (int i = 0; i < pluginCount; ++i) {
-        const QJsonObject metaData = metaDataList.at(i).value(QLatin1String("MetaData")).toObject();
-        const QJsonArray keys = metaData.value(QLatin1String("Keys")).toArray();
-        const QJsonArray mimeTypes = metaData.value(QLatin1String("MimeTypes")).toArray();
-        QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(loader->instance(i));
-        const int keyCount = keys.size();
-        for (int k = 0; k < keyCount; ++k) {
-            if (plugin && (plugin->capabilities(0, keys.at(k).toString().toLatin1()) & cap) != 0)
-                result->append(mimeTypes.at(k).toString().toLatin1());
-        }
-    }
-}
-#endif // QT_NO_IMAGEFORMATPLUGIN
-
 /*!
     Returns the list of image formats supported by QImageWriter.
 
@@ -897,30 +847,7 @@ void supportedImageHandlerMimeTypes(QFactoryLoader *loader,
 */
 QList<QByteArray> QImageWriter::supportedImageFormats()
 {
-    QList<QByteArray> formats;
-#ifndef QT_NO_IMAGEFORMAT_BMP
-    formats << "bmp";
-#endif
-#ifndef QT_NO_IMAGEFORMAT_PPM
-    formats << "pbm" << "pgm" << "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_IMAGEFORMATPLUGIN
-    supportedImageHandlerFormats(loader(), QImageIOPlugin::CanWrite, &formats);
-#endif // QT_NO_IMAGEFORMATPLUGIN
-
-    std::sort(formats.begin(), formats.end());
-    formats.erase(std::unique(formats.begin(), formats.end()), formats.end());
-    return formats;
+    return QImageReaderWriterHelpers::supportedImageFormats(QImageReaderWriterHelpers::CanWrite);
 }
 
 /*!
@@ -933,32 +860,7 @@ QList<QByteArray> QImageWriter::supportedImageFormats()
 */
 QList<QByteArray> QImageWriter::supportedMimeTypes()
 {
-    QList<QByteArray> mimeTypes;
-#ifndef QT_NO_IMAGEFORMAT_BMP
-    mimeTypes << "image/bmp";
-#endif
-#ifndef QT_NO_IMAGEFORMAT_PPM
-    mimeTypes << "image/x-portable-bitmap";
-    mimeTypes << "image/x-portable-graymap";
-    mimeTypes << "image/x-portable-pixmap";
-#endif
-#ifndef QT_NO_IMAGEFORMAT_XBM
-    mimeTypes << "image/x-xbitmap";
-#endif
-#ifndef QT_NO_IMAGEFORMAT_XPM
-    mimeTypes << "image/x-xpixmap";
-#endif
-#ifndef QT_NO_IMAGEFORMAT_PNG
-    mimeTypes << "image/png";
-#endif
-
-#ifndef QT_NO_IMAGEFORMATPLUGIN
-    supportedImageHandlerMimeTypes(loader(), QImageIOPlugin::CanWrite, &mimeTypes);
-#endif // QT_NO_IMAGEFORMATPLUGIN
-
-    std::sort(mimeTypes.begin(), mimeTypes.end());
-    mimeTypes.erase(std::unique(mimeTypes.begin(), mimeTypes.end()), mimeTypes.end());
-    return mimeTypes;
+    return QImageReaderWriterHelpers::supportedMimeTypes(QImageReaderWriterHelpers::CanWrite);
 }
 
 QT_END_NAMESPACE