Improve QWaylandExtension

By using curiously recurring template pattern we can generate a getter
which is very convenient, and all QWaylandExtensions should have this
casting operation

Change-Id: Idb5a786655f2e106cf5388b11ed71e8b6ddddec0

3 files changed, 34 insertions, 53 deletions

diff --git a/src/compositor/global/qwaylandextension.cpp b/src/compositor/global/qwaylandextension.cpp
index 55fd994ee..e255aecc3 100644
--- a/src/compositor/global/qwaylandextension.cpp
+++ b/src/compositor/global/qwaylandextension.cpp
@@ -70,7 +70,7 @@ QWaylandExtensionContainer::~QWaylandExtensionContainer()
 QWaylandExtension *QWaylandExtensionContainer::extension(const QByteArray &name)
 {
     for (int i = 0; i < extension_vector.size(); i++) {
-        if (extension_vector.at(i)->name() == name)
+        if (extension_vector.at(i)->extensionInterface()->name == name)
             return extension_vector.at(i);
     }
     return Q_NULLPTR;
@@ -79,7 +79,7 @@ QWaylandExtension *QWaylandExtensionContainer::extension(const QByteArray &name)
 QWaylandExtension *QWaylandExtensionContainer::extension(const wl_interface *interface)
 {
     for (int i = 0; i < extension_vector.size(); i++) {
-        if (extension_vector.at(i)->interface() == interface)
+        if (extension_vector.at(i)->extensionInterface() == interface)
             return extension_vector.at(i);
     }
     return Q_NULLPTR;
@@ -101,18 +101,4 @@ void QWaylandExtensionContainer::removeExtension(QWaylandExtension *extension)
     extension_vector.removeOne(extension);
 }
 
-QWaylandExtensionTemplate::QWaylandExtensionTemplate(QWaylandExtensionContainer *container, QObject *parent)
-    : QWaylandExtension(container, parent)
-{ }
-
-QWaylandExtensionTemplate::QWaylandExtensionTemplate(QWaylandExtensionTemplatePrivate &dd, QObject *parent)
-    : QWaylandExtension(dd, parent)
-{ }
-
-const struct wl_interface *QWaylandExtensionTemplate::interface() const
-{
-    Q_D(const QWaylandExtensionTemplate);
-    return d->interface();
-}
-
 QT_END_NAMESPACE
diff --git a/src/compositor/global/qwaylandextension.h b/src/compositor/global/qwaylandextension.h
index e31c6398d..dbb87a99b 100644
--- a/src/compositor/global/qwaylandextension.h
+++ b/src/compositor/global/qwaylandextension.h
@@ -46,27 +46,10 @@
 QT_BEGIN_NAMESPACE
 
 class QWaylandCompositor;
-class QWaylandExtensionContainer;
+class QWaylandExtension;
 class QWaylandExtensionPrivate;
 class QWaylandExtensionTemplatePrivate;
 
-class Q_COMPOSITOR_EXPORT QWaylandExtension : public QObject
-{
-    Q_OBJECT
-    Q_DECLARE_PRIVATE(QWaylandExtension)
-public:
-    QWaylandExtension(QWaylandExtensionContainer *container, QObject *parent = 0);
-    virtual ~QWaylandExtension();
-
-    virtual const struct wl_interface *interface() const = 0;
-
-    const QByteArray name() const { return interface()->name; }
-    quint32 version() const { return interface()->version; }
-
-protected:
-    QWaylandExtension(QWaylandExtensionPrivate &dd, QObject *parent = 0);
-};
-
 class Q_COMPOSITOR_EXPORT QWaylandExtensionContainer
 {
 public:
@@ -82,17 +65,44 @@ protected:
     QVector<QWaylandExtension *> extension_vector;
 };
 
-class Q_COMPOSITOR_EXPORT QWaylandExtensionTemplate : public QWaylandExtension
+class Q_COMPOSITOR_EXPORT QWaylandExtension : public QObject
 {
     Q_OBJECT
+    Q_DECLARE_PRIVATE(QWaylandExtension)
+public:
+    QWaylandExtension(QWaylandExtensionContainer *container, QObject *parent = 0);
+    virtual ~QWaylandExtension();
+
+    virtual const struct wl_interface *extensionInterface() const = 0;
+
+protected:
+    QWaylandExtension(QWaylandExtensionPrivate &dd, QObject *parent = 0);
+};
+
+template <typename T>
+class Q_COMPOSITOR_EXPORT QWaylandExtensionTemplate : public QWaylandExtension
+{
     Q_DECLARE_PRIVATE(QWaylandExtensionTemplate)
 public:
-    QWaylandExtensionTemplate(QWaylandExtensionContainer *container, QObject *parent = 0);
+    QWaylandExtensionTemplate(QWaylandExtensionContainer *container, QObject *parent = 0)
+        : QWaylandExtension(container, parent)
+    { }
+
+    const struct wl_interface *extensionInterface() const Q_DECL_OVERRIDE
+    {
+        return T::interface();
+    }
 
-    const struct wl_interface *interface() const Q_DECL_OVERRIDE;
+    static T *get(QWaylandExtensionContainer *container)
+    {
+        if (!container) return Q_NULLPTR;
+        return qobject_cast<T *>(container->extension(T::interfaceName()));
+    }
 
 protected:
-    QWaylandExtensionTemplate(QWaylandExtensionTemplatePrivate &dd, QObject *parent = 0);
+    QWaylandExtensionTemplate(QWaylandExtensionTemplatePrivate &dd, QObject *parent = 0)
+        : QWaylandExtension(dd, parent)
+    { }
 };
 
 QT_END_NAMESPACE
diff --git a/src/compositor/global/qwaylandextension_p.h b/src/compositor/global/qwaylandextension_p.h
index b86943650..5ca5bd3cf 100644
--- a/src/compositor/global/qwaylandextension_p.h
+++ b/src/compositor/global/qwaylandextension_p.h
@@ -56,25 +56,10 @@ public:
 
 class Q_COMPOSITOR_EXPORT QWaylandExtensionTemplatePrivate : public QWaylandExtensionPrivate
 {
-    Q_DECLARE_PUBLIC(QWaylandExtension)
-
 public:
     QWaylandExtensionTemplatePrivate(QWaylandExtensionContainer *container)
         : QWaylandExtensionPrivate(container)
-    {}
-
-    virtual const struct wl_interface *interface() const = 0;
-};
-
-template <typename T>
-class Q_COMPOSITOR_EXPORT QWaylandExtensionTemplatePrivateImpl : public QWaylandExtensionTemplatePrivate, public T
-{
-public:
-    QWaylandExtensionTemplatePrivateImpl(QWaylandExtensionContainer *container)
-        : QWaylandExtensionTemplatePrivate(container)
     { }
-
-    const struct wl_interface *interface() const Q_DECL_OVERRIDE { return T::interface(); }
 };
 
 #endif  /*QWAYLANDEXTENSION_P_H*/