Don't inherit from QFactoryInterface for image plugins

QFactoryInterface is obsolete now that we have the new plugins loading
mechanism, where we can get the keys out of the plugin without
having to load it. Remove it from QImageIOHandlerFactoryInterface
as a first step of getting completely rid of it.

Change-Id: I856b149dd20131e1cdcdcb271c1a355c9e0da6ab
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/gui/image/qimageiohandler.cpp

@@ -171,9 +171,9 @@
     support for different image formats to Qt.
 
     Writing an image I/O plugin is achieved by subclassing this
-    base class, reimplementing the pure virtual functions capabilities(),
-    create(), and keys(), and exporting the class with the
-    Q_EXPORT_PLUGIN2() macro. See \l{How to Create Qt Plugins} for details.
+    base class, reimplementing the pure virtual functions capabilities()
+    and create(), and exporting the class with the
+    Q_PLUGIN_METADATA() macro. See \l{How to Create Qt Plugins} for details.
 
     An image format plugin can support three capabilities: reading (\l
     CanRead), writing (\l CanWrite) and \e incremental reading (\l
@@ -182,8 +182,15 @@
 
     create() should create an instance of your QImageIOHandler
     subclass, with the provided device and format properly set, and
-    return this handler. You must also reimplement keys() so that Qt
-    knows which image formats your plugin supports.
+    return this handler.
+
+    The json metadata file for the plugin needs to contain information
+    about the image formats the plugins supports. For a jpeg plugin, this
+    could e.g. look as follows:
+
+    \code
+    { "Keys": [ "jpg", "jpeg" ] }
+    \endcode
 
     Different plugins can support different capabilities. For example,
     you may have one plugin that supports reading the GIF format, and
@@ -205,17 +212,6 @@
     \value CanReadIncremental The plugin can read images incrementally.
 */
 
-/*!
-    \class QImageIOHandlerFactoryInterface
-    \brief The QImageIOHandlerFactoryInterface class provides the factory
-    interface for QImageIOPlugin.
-    \reentrant
-
-    \internal
-
-    \sa QImageIOPlugin
-*/
-
 #include "qimageiohandler.h"
 
 #include <qbytearray.h>
@@ -546,17 +542,6 @@ QImageIOPlugin::~QImageIOPlugin()
     \l CanWrite.
 */
 
-/*!
-    \fn QImageIOPlugin::keys() const
-
-    Returns the list of image keys this plugin supports.
-
-    These keys are usually the names of the image formats that are implemented
-    in the plugin (e.g., "jpg" or "gif").
-
-    \sa capabilities()
-*/
-
 /*!
     \fn QImageIOHandler *QImageIOPlugin::create(QIODevice *device, const QByteArray &format) const
 

src/gui/image/qimageiohandler.h

@@ -114,18 +114,11 @@ private:
     Q_DISABLE_COPY(QImageIOHandler)
 };
 
-struct Q_GUI_EXPORT QImageIOHandlerFactoryInterface : public QFactoryInterface
-{
-    virtual QImageIOHandler *create(QIODevice *device, const QByteArray &format = QByteArray()) const = 0;
-};
-
 #define QImageIOHandlerFactoryInterface_iid "org.qt-project.Qt.QImageIOHandlerFactoryInterface"
-Q_DECLARE_INTERFACE(QImageIOHandlerFactoryInterface, QImageIOHandlerFactoryInterface_iid)
 
-class Q_GUI_EXPORT QImageIOPlugin : public QObject, public QImageIOHandlerFactoryInterface
+class Q_GUI_EXPORT QImageIOPlugin : public QObject
 {
     Q_OBJECT
-    Q_INTERFACES(QImageIOHandlerFactoryInterface:QFactoryInterface)
 public:
     explicit QImageIOPlugin(QObject *parent = 0);
     virtual ~QImageIOPlugin();
@@ -138,7 +131,6 @@ public:
     Q_DECLARE_FLAGS(Capabilities, Capability)
 
     virtual Capabilities capabilities(QIODevice *device, const QByteArray &format) const = 0;
-    virtual QStringList keys() const = 0;
     virtual QImageIOHandler *create(QIODevice *device, const QByteArray &format = QByteArray()) const = 0;
 };
 

src/plugins/imageformats/gif/main.cpp

@@ -62,11 +62,6 @@ QGifPlugin::~QGifPlugin()
 {
 }
 
-QStringList QGifPlugin::keys() const
-{
-    return QStringList() << QLatin1String("gif");
-}
-
 QImageIOPlugin::Capabilities QGifPlugin::capabilities(QIODevice *device, const QByteArray &format) const
 {
     if (format == "gif" || (device && device->isReadable() && QGifHandler::canRead(device)))

src/plugins/imageformats/gif/main.h

@@ -57,7 +57,6 @@ public:
     QGifPlugin();
     ~QGifPlugin();
 
-    QStringList keys() const;
     Capabilities capabilities(QIODevice *device, const QByteArray &format) const;
     QImageIOHandler *create(QIODevice *device, const QByteArray &format = QByteArray()) const;
 };

src/plugins/imageformats/ico/main.cpp

@@ -45,11 +45,6 @@
 
 QT_BEGIN_NAMESPACE
 
-QStringList QICOPlugin::keys() const
-{
-    return QStringList() << QLatin1String("ico");
-}
-
 QImageIOPlugin::Capabilities QICOPlugin::capabilities(QIODevice *device, const QByteArray &format) const
 {
     if (format == "ico")

src/plugins/imageformats/ico/main.h

@@ -56,7 +56,6 @@ class QICOPlugin : public QImageIOPlugin
     Q_OBJECT
     Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QImageIOHandlerFactoryInterface" FILE "ico.json")
 public:
-    QStringList keys() const;
     Capabilities capabilities(QIODevice *device, const QByteArray &format) const;
     QImageIOHandler *create(QIODevice *device, const QByteArray &format = QByteArray()) const;
 };

src/plugins/imageformats/jpeg/main.cpp

@@ -50,11 +50,6 @@
 
 QT_BEGIN_NAMESPACE
 
-QStringList QJpegPlugin::keys() const
-{
-    return QStringList() << QLatin1String("jpeg") << QLatin1String("jpg");
-}
-
 QImageIOPlugin::Capabilities QJpegPlugin::capabilities(QIODevice *device, const QByteArray &format) const
 {
     if (format == "jpeg" || format == "jpg")

src/plugins/imageformats/jpeg/main.h

@@ -55,7 +55,6 @@ class QJpegPlugin : public QImageIOPlugin
     Q_OBJECT
     Q_PLUGIN_METADATA(IID "org.qt-project.Qt.QImageIOHandlerFactoryInterface" FILE "jpeg.json")
 public:
-    QStringList keys() const;
     Capabilities capabilities(QIODevice *device, const QByteArray &format) const;
     QImageIOHandler *create(QIODevice *device, const QByteArray &format = QByteArray()) const;
 };