Remove QIconEngineV2 and fold it into QIconEngine

Change-Id: Ife590b7639f4aadcfbd4d77ca170285b623c14ae
Reviewed-by: Jonas Gastal <jgastal@profusion.mobi>
Reviewed-by: Gunnar Sletta <gunnar.sletta@nokia.com>

9 files changed, 67 insertions, 271 deletions

diff --git a/src/widgets/kernel/qicon.cpp b/src/widgets/kernel/qicon.cpp
index 52fe2f8ebe..1d3236aa46 100644
--- a/src/widgets/kernel/qicon.cpp
+++ b/src/widgets/kernel/qicon.cpp
@@ -128,9 +128,7 @@ static void qt_cleanup_icon_cache()
 QIconPrivate::QIconPrivate()
     : engine(0), ref(1),
     serialNum(serialNumCounter.fetchAndAddRelaxed(1)),
-    detach_no(0),
-    engine_version(2),
-    v1RefCount(0)
+    detach_no(0)
 {
 }
 
@@ -139,7 +137,7 @@ QPixmapIconEngine::QPixmapIconEngine()
 }
 
 QPixmapIconEngine::QPixmapIconEngine(const QPixmapIconEngine &other)
-    : QIconEngineV2(other), pixmaps(other.pixmaps)
+    : QIconEngine(other), pixmaps(other.pixmaps)
 {
 }
 
@@ -374,7 +372,7 @@ QString QPixmapIconEngine::key() const
     return QLatin1String("QPixmapIconEngine");
 }
 
-QIconEngineV2 *QPixmapIconEngine::clone() const
+QIconEngine *QPixmapIconEngine::clone() const
 {
     return new QPixmapIconEngine(*this);
 }
@@ -430,9 +428,9 @@ bool QPixmapIconEngine::write(QDataStream &out) const
 void QPixmapIconEngine::virtual_hook(int id, void *data)
 {
     switch (id) {
-    case QIconEngineV2::AvailableSizesHook: {
-        QIconEngineV2::AvailableSizesArgument &arg =
-            *reinterpret_cast<QIconEngineV2::AvailableSizesArgument*>(data);
+    case QIconEngine::AvailableSizesHook: {
+        QIconEngine::AvailableSizesArgument &arg =
+            *reinterpret_cast<QIconEngine::AvailableSizesArgument*>(data);
         arg.sizes.clear();
         for (int i = 0; i < pixmaps.size(); ++i) {
             QPixmapIconEngineEntry &pe = pixmaps[i];
@@ -446,15 +444,13 @@ void QPixmapIconEngine::virtual_hook(int id, void *data)
         break;
     }
     default:
-        QIconEngineV2::virtual_hook(id, data);
+        QIconEngine::virtual_hook(id, data);
     }
 }
 
 #ifndef QT_NO_LIBRARY
 Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loader,
     (QIconEngineFactoryInterface_iid, QLatin1String("/iconengines"), Qt::CaseInsensitive))
-Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loaderV2,
-    (QIconEngineFactoryInterfaceV2_iid, QLatin1String("/iconengines"), Qt::CaseInsensitive))
 #endif
 
 
@@ -584,19 +580,6 @@ QIcon::QIcon(const QString &fileName)
 QIcon::QIcon(QIconEngine *engine)
     :d(new QIconPrivate)
 {
-    d->engine_version = 1;
-    d->engine = engine;
-    d->v1RefCount = new QAtomicInt(1);
-}
-
-/*!
-    Creates an icon with a specific icon \a engine. The icon takes
-    ownership of the engine.
-*/
-QIcon::QIcon(QIconEngineV2 *engine)
-    :d(new QIconPrivate)
-{
-    d->engine_version = 2;
     d->engine = engine;
 }
 
@@ -777,15 +760,7 @@ void QIcon::detach()
     if (d) {
         if (d->ref.load() != 1) {
             QIconPrivate *x = new QIconPrivate;
-            if (d->engine_version > 1) {
-                QIconEngineV2 *engine = static_cast<QIconEngineV2 *>(d->engine);
-                x->engine = engine->clone();
-            } else {
-                x->engine = d->engine;
-                x->v1RefCount = d->v1RefCount;
-                x->v1RefCount->ref();
-            }
-            x->engine_version = d->engine_version;
+            x->engine = d->engine->clone();
             if (!d->ref.deref())
                 delete d;
             d = x;
@@ -851,23 +826,12 @@ void QIcon::addFile(const QString &fileName, const QSize &size, Mode mode, State
         QString suffix = info.suffix();
         if (!suffix.isEmpty()) {
             // first try version 2 engines..
-            if (QIconEngineFactoryInterfaceV2 *factory = qobject_cast<QIconEngineFactoryInterfaceV2*>(loaderV2()->instance(suffix))) {
+            if (QIconEngineFactoryInterface *factory = qobject_cast<QIconEngineFactoryInterface*>(loader()->instance(suffix))) {
                 if (QIconEngine *engine = factory->create(fileName)) {
                     d = new QIconPrivate;
                     d->engine = engine;
                 }
             }
-            // ..then fall back and try to load version 1 engines
-            if (!d) {
-                if (QIconEngineFactoryInterface *factory = qobject_cast<QIconEngineFactoryInterface*>(loader()->instance(suffix))) {
-                    if (QIconEngine *engine = factory->create(fileName)) {
-                        d = new QIconPrivate;
-                        d->engine = engine;
-                        d->engine_version = 1;
-                        d->v1RefCount = new QAtomicInt(1);
-                    }
-                }
-            }
         }
 #endif
         // ...then fall back to the default engine
@@ -889,10 +853,9 @@ void QIcon::addFile(const QString &fileName, const QSize &size, Mode mode, State
 */
 QList<QSize> QIcon::availableSizes(Mode mode, State state) const
 {
-    if (!d || !d->engine || d->engine_version < 2)
+    if (!d || !d->engine)
         return QList<QSize>();
-    QIconEngineV2 *engine = static_cast<QIconEngineV2*>(d->engine);
-    return engine->availableSizes(mode, state);
+    return d->engine->availableSizes(mode, state);
 }
 
 /*!
@@ -908,10 +871,9 @@ QList<QSize> QIcon::availableSizes(Mode mode, State state) const
 */
 QString QIcon::name() const
 {
-    if (!d || !d->engine || d->engine_version < 2)
+    if (!d || !d->engine)
         return QString();
-    QIconEngineV2 *engine = static_cast<QIconEngineV2*>(d->engine);
-    return engine->iconName();
+    return d->engine->iconName();
 }
 
 /*!
@@ -1066,14 +1028,8 @@ QDataStream &operator<<(QDataStream &s, const QIcon &icon)
         if (icon.isNull()) {
             s << QString();
         } else {
-            if (icon.d->engine_version > 1) {
-                QIconEngineV2 *engine = static_cast<QIconEngineV2 *>(icon.d->engine);
-                s << engine->key();
-                engine->write(s);
-            } else {
-                // not really supported
-                qWarning("QIcon: Cannot stream QIconEngine. Use QIconEngineV2 instead.");
-            }
+            s << icon.d->engine->key();
+            icon.d->engine->write(s);
         }
     } else if (s.version() == QDataStream::Qt_4_2) {
         if (icon.isNull()) {
@@ -1113,17 +1069,17 @@ QDataStream &operator>>(QDataStream &s, QIcon &icon)
         s >> key;
         if (key == QLatin1String("QPixmapIconEngine")) {
             icon.d = new QIconPrivate;
-            QIconEngineV2 *engine = new QPixmapIconEngine;
+            QIconEngine *engine = new QPixmapIconEngine;
             icon.d->engine = engine;
             engine->read(s);
         } else if (key == QLatin1String("QIconLoaderEngine")) {
             icon.d = new QIconPrivate;
-            QIconEngineV2 *engine = new QIconLoaderEngine();
+            QIconEngine *engine = new QIconLoaderEngine();
             icon.d->engine = engine;
             engine->read(s);
 #if !defined (QT_NO_LIBRARY) && !defined(QT_NO_SETTINGS)
-        } else if (QIconEngineFactoryInterfaceV2 *factory = qobject_cast<QIconEngineFactoryInterfaceV2*>(loaderV2()->instance(key))) {
-            if (QIconEngineV2 *engine= factory->create()) {
+        } else if (QIconEngineFactoryInterface *factory = qobject_cast<QIconEngineFactoryInterface*>(loader()->instance(key))) {
+            if (QIconEngine *engine= factory->create()) {
                 icon.d = new QIconPrivate;
                 icon.d->engine = engine;
                 engine->read(s);
diff --git a/src/widgets/kernel/qicon.h b/src/widgets/kernel/qicon.h
index d7c2f8f49a..7bef500946 100644
--- a/src/widgets/kernel/qicon.h
+++ b/src/widgets/kernel/qicon.h
@@ -54,7 +54,6 @@ QT_BEGIN_NAMESPACE
 
 class QIconPrivate;
 class QIconEngine;
-class QIconEngineV2;
 
 class Q_WIDGETS_EXPORT QIcon
 {
@@ -67,7 +66,6 @@ public:
     QIcon(const QIcon &other);
     explicit QIcon(const QString &fileName); // file or resource name
     explicit QIcon(QIconEngine *engine);
-    explicit QIcon(QIconEngineV2 *engine);
     ~QIcon();
     QIcon &operator=(const QIcon &other);
 #ifdef Q_COMPILER_RVALUE_REFS
diff --git a/src/widgets/kernel/qicon_p.h b/src/widgets/kernel/qicon_p.h
index 378e913f95..37c4b7cb1f 100644
--- a/src/widgets/kernel/qicon_p.h
+++ b/src/widgets/kernel/qicon_p.h
@@ -69,14 +69,7 @@ public:
     QIconPrivate();
 
     ~QIconPrivate() {
-        if (engine_version == 1) {
-            if (!v1RefCount->deref()) {
-                delete engine;
-                delete v1RefCount;
-            }
-        } else if (engine_version == 2) {
-            delete engine;
-        }
+        delete engine;
     }
 
     QIconEngine *engine;
@@ -84,9 +77,6 @@ public:
     QAtomicInt ref;
     int serialNum;
     int detach_no;
-    int engine_version;
-
-    QAtomicInt *v1RefCount;
 };
 
 
@@ -107,7 +97,7 @@ struct QPixmapIconEngineEntry
 
 
 
-class QPixmapIconEngine : public QIconEngineV2 {
+class QPixmapIconEngine : public QIconEngine {
 public:
     QPixmapIconEngine();
     QPixmapIconEngine(const QPixmapIconEngine &);
@@ -119,9 +109,8 @@ public:
     void addPixmap(const QPixmap &pixmap, QIcon::Mode mode, QIcon::State state);
     void addFile(const QString &fileName, const QSize &size, QIcon::Mode mode, QIcon::State state);
 
-    // v2 functions
     QString key() const;
-    QIconEngineV2 *clone() const;
+    QIconEngine *clone() const;
     bool read(QDataStream &in);
     bool write(QDataStream &out) const;
     void virtual_hook(int id, void *data);
diff --git a/src/widgets/kernel/qiconengine.cpp b/src/widgets/kernel/qiconengine.cpp
index 9f36d7e50e..0a2d92ed69 100644
--- a/src/widgets/kernel/qiconengine.cpp
+++ b/src/widgets/kernel/qiconengine.cpp
@@ -52,8 +52,6 @@ QT_BEGIN_NAMESPACE
   \ingroup painting
   \inmodule QtWidgets
 
-  \bold {Use QIconEngineV2 instead.}
-
   An icon engine provides the rendering functions for a QIcon. Each icon has a
   corresponding icon engine that is responsible for drawing the icon with a
   requested size, mode and state.
@@ -67,7 +65,7 @@ QT_BEGIN_NAMESPACE
   The paint(), pixmap(), and addPixmap() functions are all virtual, and can
   therefore be reimplemented in subclasses of QIconEngine.
 
-  \sa QIconEngineV2, QIconEnginePlugin
+  \sa QIconEnginePlugin
 
 */
 
@@ -136,45 +134,8 @@ void QIconEngine::addFile(const QString &/*fileName*/, const QSize &/*size*/, QI
 }
 
 
-
-// version 2 functions
-
-
 /*!
-    \class QIconEngineV2
-
-    \brief The QIconEngineV2 class provides an abstract base class for QIcon renderers.
-
-    \ingroup painting
-    \inmodule QtWidgets
-
-    \since 4.3
-
-    An icon engine renders \l{QIcon}s. With icon engines, you can
-    customize icons. Qt provides a default engine that makes icons
-    adhere to the current style by scaling the icons and providing a
-    disabled appearance.
-
-    An engine is installed on an icon either through a QIcon
-    constructor or through a QIconEnginePluginV2. The plugins are used
-    by Qt if a specific engine is not given when the icon is created.
-    See the QIconEngineV2 class description to learn how to create
-    icon engine plugins.
-
-    An icon engine provides the rendering functions for a QIcon. Each
-    icon has a corresponding icon engine that is responsible for drawing
-    the icon with a requested size, mode and state.
-
-    QIconEngineV2 extends the API of QIconEngine to allow streaming of
-    the icon engine contents, and should be used instead of QIconEngine
-    for implementing new icon engines.
-
-    \sa QIconEnginePluginV2
-
-*/
-
-/*!
-    \enum QIconEngineV2::IconEngineHook
+    \enum QIconEngine::IconEngineHook
     \since 4.5
 
     These enum values are used for virtual_hook() to allow additional
@@ -194,33 +155,33 @@ void QIconEngine::addFile(const QString &/*fileName*/, const QSize &/*size*/, QI
  */
 
 /*!
-    \class QIconEngineV2::AvailableSizesArgument
+    \class QIconEngine::AvailableSizesArgument
     \since 4.5
 
     \inmodule QtWidgets
 
     This struct represents arguments to virtual_hook() function when
-    \a id parameter is QIconEngineV2::AvailableSizesHook.
+    \a id parameter is QIconEngine::AvailableSizesHook.
 
-    \sa virtual_hook(), QIconEngineV2::IconEngineHook
+    \sa virtual_hook(), QIconEngine::IconEngineHook
  */
 
 /*!
-    \variable QIconEngineV2::AvailableSizesArgument::mode
+    \variable QIconEngine::AvailableSizesArgument::mode
     \brief the requested mode of an image.
 
     \sa QIcon::Mode
 */
 
 /*!
-    \variable QIconEngineV2::AvailableSizesArgument::state
+    \variable QIconEngine::AvailableSizesArgument::state
     \brief the requested state of an image.
 
     \sa QIcon::State
 */
 
 /*!
-    \variable QIconEngineV2::AvailableSizesArgument::sizes
+    \variable QIconEngine::AvailableSizesArgument::sizes
 
     \brief image sizes that are available with specified \a mode and
     \a state. This is an output parameter and is filled after call to
@@ -232,26 +193,23 @@ void QIconEngine::addFile(const QString &/*fileName*/, const QSize &/*size*/, QI
 /*!
     Returns a key that identifies this icon engine.
  */
-QString QIconEngineV2::key() const
+QString QIconEngine::key() const
 {
     return QString();
 }
 
-/*!
-    Returns a clone of this icon engine.
+/*! \fn QIconEngine *QIconEngine::clone() const
+
+    Reimplement this method to return a clone of this icon engine.
  */
-QIconEngineV2 *QIconEngineV2::clone() const
-{
-    return 0;
-}
 
 /*!
     Reads icon engine contents from the QDataStream \a in. Returns
     true if the contents were read; otherwise returns false.
 
-    QIconEngineV2's default implementation always return false.
+    QIconEngine's default implementation always return false.
  */
-bool QIconEngineV2::read(QDataStream &)
+bool QIconEngine::read(QDataStream &)
 {
     return false;
 }
@@ -260,9 +218,9 @@ bool QIconEngineV2::read(QDataStream &)
     Writes the contents of this engine to the QDataStream \a out.
     Returns true if the contents were written; otherwise returns false.
 
-    QIconEngineV2's default implementation always return false.
+    QIconEngine's default implementation always return false.
  */
-bool QIconEngineV2::write(QDataStream &) const
+bool QIconEngine::write(QDataStream &) const
 {
     return false;
 }
@@ -270,19 +228,19 @@ bool QIconEngineV2::write(QDataStream &) const
 /*!
     \since 4.5
 
-    Additional method to allow extending QIconEngineV2 without
+    Additional method to allow extending QIconEngine without
     adding new virtual methods (and without breaking binary compatibility).
     The actual action and format of \a data depends on \a id argument
     which is in fact a constant from IconEngineHook enum.
 
     \sa IconEngineHook
 */
-void QIconEngineV2::virtual_hook(int id, void *data)
+void QIconEngine::virtual_hook(int id, void *data)
 {
     switch (id) {
-    case QIconEngineV2::AvailableSizesHook: {
-        QIconEngineV2::AvailableSizesArgument &arg =
-            *reinterpret_cast<QIconEngineV2::AvailableSizesArgument*>(data);
+    case QIconEngine::AvailableSizesHook: {
+        QIconEngine::AvailableSizesArgument &arg =
+            *reinterpret_cast<QIconEngine::AvailableSizesArgument*>(data);
         arg.sizes.clear();
         break;
     }
@@ -301,12 +259,12 @@ void QIconEngineV2::virtual_hook(int id, void *data)
     virtual_hook() method, hence this method depends on icon engine support
     and may not work with all icon engines.
  */
-QList<QSize> QIconEngineV2::availableSizes(QIcon::Mode mode, QIcon::State state)
+QList<QSize> QIconEngine::availableSizes(QIcon::Mode mode, QIcon::State state) const
 {
     AvailableSizesArgument arg;
     arg.mode = mode;
     arg.state = state;
-    virtual_hook(QIconEngineV2::AvailableSizesHook, reinterpret_cast<void*>(&arg));
+    const_cast<QIconEngine *>(this)->virtual_hook(QIconEngine::AvailableSizesHook, reinterpret_cast<void*>(&arg));
     return arg.sizes;
 }
 
@@ -319,10 +277,10 @@ QList<QSize> QIconEngineV2::availableSizes(QIcon::Mode mode, QIcon::State state)
     virtual_hook() method, hence this method depends on icon engine support
     and may not work with all icon engines.
  */
-QString QIconEngineV2::iconName()
+QString QIconEngine::iconName() const
 {
     QString name;
-    virtual_hook(QIconEngineV2::IconNameHook, reinterpret_cast<void*>(&name));
+    const_cast<QIconEngine *>(this)->virtual_hook(QIconEngine::IconNameHook, reinterpret_cast<void*>(&name));
     return name;
 }
 
diff --git a/src/widgets/kernel/qiconengine.h b/src/widgets/kernel/qiconengine.h
index 99e1b72e2f..9f964043bc 100644
--- a/src/widgets/kernel/qiconengine.h
+++ b/src/widgets/kernel/qiconengine.h
@@ -62,23 +62,11 @@ public:
     virtual void addPixmap(const QPixmap &pixmap, QIcon::Mode mode, QIcon::State state);
     virtual void addFile(const QString &fileName, const QSize &size, QIcon::Mode mode, QIcon::State state);
 
-#if 0
-    virtual int frameCount(QIcon::Mode fromMode, QIcon::State fromState, QIcon::Mode toMode, QIcon::State toState);
-    virtual void paintFrame(QPainter *painter, const QRect &rect, int frameNumber, QIcon::Mode fromMode, QIcon::State fromState, QIcon::Mode toMode, QIcon::State toState);
-#endif
-};
-
-// ### Qt 5: move the below into QIconEngine
-class Q_WIDGETS_EXPORT QIconEngineV2 : public QIconEngine
-{
-public:
     virtual QString key() const;
-    virtual QIconEngineV2 *clone() const;
+    virtual QIconEngine *clone() const = 0;
     virtual bool read(QDataStream &in);
     virtual bool write(QDataStream &out) const;
-    virtual void virtual_hook(int id, void *data);
 
-public:
     enum IconEngineHook { AvailableSizesHook = 1, IconNameHook };
 
     struct AvailableSizesArgument
@@ -88,12 +76,12 @@ public:
         QList<QSize> sizes;
     };
 
-    // ### Qt 5: make this function const and virtual.
-    QList<QSize> availableSizes(QIcon::Mode mode = QIcon::Normal,
-                                QIcon::State state = QIcon::Off);
+    virtual QList<QSize> availableSizes(QIcon::Mode mode = QIcon::Normal,
+                                    QIcon::State state = QIcon::Off) const;
 
-    // ### Qt 5: make this function const and virtual.
-    QString iconName();
+    virtual QString iconName() const;
+
+    virtual void virtual_hook(int id, void *data);
 };
 
 QT_END_NAMESPACE
diff --git a/src/widgets/kernel/qiconengineplugin.cpp b/src/widgets/kernel/qiconengineplugin.cpp
index fbf3463da9..ced4f5dd3e 100644
--- a/src/widgets/kernel/qiconengineplugin.cpp
+++ b/src/widgets/kernel/qiconengineplugin.cpp
@@ -103,72 +103,5 @@ QIconEnginePlugin::~QIconEnginePlugin()
 {
 }
 
-// version 2
-
-/*!
-    \class QIconEnginePluginV2
-    \brief The QIconEnginePluginV2 class provides an abstract base for custom QIconEngineV2 plugins.
-
-    \ingroup plugins
-    \inmodule QtWidgets
-
-    \since 4.3
- 
-    Icon engine plugins produces \l{QIconEngine}s for \l{QIcon}s; an
-    icon engine is used to render the icon. The keys that identifies
-    the engines the plugin can create are suffixes of 
-    icon filenames; they are returned by keys(). The create() function
-    receives the icon filename to return an engine for; it should
-    return 0 if it cannot produce an engine for the file.
-
-    Writing an icon engine plugin is achieved by inheriting
-    QIconEnginePluginV2, reimplementing keys() and create(), and
-    adding the Q_EXPORT_PLUGIN2() macro.
-
-    You should ensure that you do not duplicate keys. Qt will query
-    the plugins for icon engines in the order in which the plugins are
-    found during plugin search (see the plugins \l{How to Create Qt
-    Plugins}{overview document}).
-
-    \sa {How to Create Qt Plugins}
-*/
-
-/*!
-    \fn QStringList QIconEnginePluginV2::keys() const
-
-    Returns a list of icon engine keys that this plugin supports. The keys correspond
-    to the suffix of the file or resource name used when the plugin was created.
-    Keys are case insensitive.
-
-    \sa create()
-*/
-
-/*!
-    \fn QIconEngineV2* QIconEnginePluginV2::create(const QString& filename = QString())
-
-    Creates and returns a QIconEngine object for the icon with the given
-    \a filename.
-
-    \sa keys()
-*/
-
-/*!
-    Constructs a icon engine plugin with the given \a parent. This is invoked
-    automatically by the Q_EXPORT_PLUGIN2() macro.
-*/
-QIconEnginePluginV2::QIconEnginePluginV2(QObject *parent)
-    : QObject(parent)
-{
-}
-
-/*!
-    Destroys the icon engine plugin.
-
-    You never have to call this explicitly. Qt destroys a plugin
-    automatically when it is no longer used.
-*/
-QIconEnginePluginV2::~QIconEnginePluginV2()
-{
-}
 
 QT_END_NAMESPACE
diff --git a/src/widgets/kernel/qiconengineplugin.h b/src/widgets/kernel/qiconengineplugin.h
index 20ddb7e4e7..a30c5475ba 100644
--- a/src/widgets/kernel/qiconengineplugin.h
+++ b/src/widgets/kernel/qiconengineplugin.h
@@ -51,11 +51,10 @@ QT_BEGIN_NAMESPACE
 
 
 class QIconEngine;
-class QIconEngineV2;
 
 struct Q_WIDGETS_EXPORT QIconEngineFactoryInterface : public QFactoryInterface
 {
-    virtual QIconEngine *create(const QString &filename) = 0;
+    virtual QIconEngine *create(const QString &filename = QString()) = 0;
 };
 
 #define QIconEngineFactoryInterface_iid \
@@ -71,29 +70,7 @@ public:
     ~QIconEnginePlugin();
 
     virtual QStringList keys() const = 0;
-    virtual QIconEngine *create(const QString &filename) = 0;
-};
-
-// ### Qt 5: remove version 2
-struct Q_WIDGETS_EXPORT QIconEngineFactoryInterfaceV2 : public QFactoryInterface
-{
-    virtual QIconEngineV2 *create(const QString &filename = QString()) = 0;
-};
-
-#define QIconEngineFactoryInterfaceV2_iid \
-    "org.qt-project.Qt.QIconEngineFactoryInterfaceV2"
-Q_DECLARE_INTERFACE(QIconEngineFactoryInterfaceV2, QIconEngineFactoryInterfaceV2_iid)
-
-class Q_WIDGETS_EXPORT QIconEnginePluginV2 : public QObject, public QIconEngineFactoryInterfaceV2
-{
-    Q_OBJECT
-    Q_INTERFACES(QIconEngineFactoryInterfaceV2:QFactoryInterface)
-public:
-    QIconEnginePluginV2(QObject *parent = 0);
-    ~QIconEnginePluginV2();
-
-    virtual QStringList keys() const = 0;
-    virtual QIconEngineV2 *create(const QString &filename = QString()) = 0;
+    virtual QIconEngine *create(const QString &filename = QString()) = 0;
 };
 
 QT_END_NAMESPACE
diff --git a/src/widgets/kernel/qiconloader.cpp b/src/widgets/kernel/qiconloader.cpp
index 9031c4c075..0b86189b5e 100644
--- a/src/widgets/kernel/qiconloader.cpp
+++ b/src/widgets/kernel/qiconloader.cpp
@@ -45,6 +45,7 @@
 #include <private/qicon_p.h>
 #include <private/qguiplatformplugin_p.h>
 
+#include <QtWidgets/QApplication>
 #include <QtWidgets/QIconEnginePlugin>
 #include <QtGui/QPixmapCache>
 #include <QtWidgets/QIconEngine>
@@ -104,7 +105,7 @@ void QIconLoader::ensureInitialized()
         if (m_systemTheme.isEmpty())
             m_systemTheme = fallbackTheme();
 #ifndef QT_NO_LIBRARY
-        QFactoryLoader iconFactoryLoader(QIconEngineFactoryInterfaceV2_iid,
+        QFactoryLoader iconFactoryLoader(QIconEngineFactoryInterface_iid,
                                          QLatin1String("/iconengines"),
                                          Qt::CaseInsensitive);
         if (iconFactoryLoader.keys().contains(QLatin1String("svg")))
@@ -322,13 +323,13 @@ QIconLoaderEngine::~QIconLoaderEngine()
 }
 
 QIconLoaderEngine::QIconLoaderEngine(const QIconLoaderEngine &other)
-        : QIconEngineV2(other),
+        : QIconEngine(other),
         m_iconName(other.m_iconName),
         m_key(0)
 {
 }
 
-QIconEngineV2 *QIconLoaderEngine::clone() const
+QIconEngine *QIconLoaderEngine::clone() const
 {
     return new QIconLoaderEngine(*this);
 }
@@ -477,7 +478,7 @@ QSize QIconLoaderEngine::actualSize(const QSize &size, QIcon::Mode mode,
             return QSize(result, result);
         }
     }
-    return QIconEngineV2::actualSize(size, mode, state);
+    return QIconEngine::actualSize(size, mode, state);
 }
 
 QPixmap PixmapEntry::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)
@@ -489,7 +490,6 @@ QPixmap PixmapEntry::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State st
     if (basePixmap.isNull())
         basePixmap.load(filename);
 
-#if 0 // ### Qt5
     int actualSize = qMin(size.width(), size.height());
     QString key = QLatin1Literal("$qt_theme_")
                   % HexString<qint64>(basePixmap.cacheKey())
@@ -507,9 +507,6 @@ QPixmap PixmapEntry::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State st
         QPixmapCache::insert(key, cachedPixmap);
     }
     return cachedPixmap;
-#else
-    return basePixmap;
-#endif
 }
 
 QPixmap ScalableEntry::pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state)
@@ -543,10 +540,10 @@ void QIconLoaderEngine::virtual_hook(int id, void *data)
     ensureLoaded();
 
     switch (id) {
-    case QIconEngineV2::AvailableSizesHook:
+    case QIconEngine::AvailableSizesHook:
         {
-            QIconEngineV2::AvailableSizesArgument &arg
-                    = *reinterpret_cast<QIconEngineV2::AvailableSizesArgument*>(data);
+            QIconEngine::AvailableSizesArgument &arg
+                    = *reinterpret_cast<QIconEngine::AvailableSizesArgument*>(data);
             const QList<QIconDirInfo> directoryKey = iconLoaderInstance()->theme().keyList();
             arg.sizes.clear();
 
@@ -557,14 +554,14 @@ void QIconLoaderEngine::virtual_hook(int id, void *data)
             }
         }
         break;
-    case QIconEngineV2::IconNameHook:
+    case QIconEngine::IconNameHook:
         {
             QString &name = *reinterpret_cast<QString*>(data);
             name = m_iconName;
         }
         break;
     default:
-        QIconEngineV2::virtual_hook(id, data);
+        QIconEngine::virtual_hook(id, data);
     }
 }
 
diff --git a/src/widgets/kernel/qiconloader_p.h b/src/widgets/kernel/qiconloader_p.h
index 9c0349cf90..1b9043675b 100644
--- a/src/widgets/kernel/qiconloader_p.h
+++ b/src/widgets/kernel/qiconloader_p.h
@@ -109,7 +109,7 @@ struct PixmapEntry : public QIconLoaderEngineEntry
 
 typedef QList<QIconLoaderEngineEntry*> QThemeIconEntries;
 
-class QIconLoaderEngine : public QIconEngineV2
+class QIconLoaderEngine : public QIconEngine
 {
 public:
     QIconLoaderEngine(const QString& iconName = QString());
@@ -118,7 +118,7 @@ public:
     void paint(QPainter *painter, const QRect &rect, QIcon::Mode mode, QIcon::State state);
     QPixmap pixmap(const QSize &size, QIcon::Mode mode, QIcon::State state);
     QSize actualSize(const QSize &size, QIcon::Mode mode, QIcon::State state);
-    QIconEngineV2 *clone() const;
+    QIconEngine *clone() const;
     bool read(QDataStream &in);
     bool write(QDataStream &out) const;