Provide imageType() from QQmlImageProviderBase

Clients who are only interested in the type of image data provided
by an image provider should not need to cast the base pointer to
a QQuickImageProvider to access this information.

Also make the QQmlImageProviderBase constructor private to prevent
unwanted inheritance; all implementors should use the
QQuickImageProvider class.

Change-Id: Ia2dd2595c2711fa7df47265c9857f45ef0f4cc41
Reviewed-by: Kent Hansen <kent.hansen@nokia.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/src/qml/qml/qqmlengine.h b/src/qml/qml/qqmlengine.h
index 41696923c5..21a03d63ce 100644
--- a/src/qml/qml/qqmlengine.h
+++ b/src/qml/qml/qqmlengine.h
@@ -57,7 +57,20 @@ QT_BEGIN_NAMESPACE
 class Q_QML_EXPORT QQmlImageProviderBase
 {
 public:
+    enum ImageType {
+        Image,
+        Pixmap,
+        Texture,
+        Invalid
+    };
+
     virtual ~QQmlImageProviderBase();
+
+    virtual ImageType imageType() const = 0;
+
+private:
+    friend class QQuickImageProvider;
+    QQmlImageProviderBase();
 };
 
 class QQmlComponent;