add a Wallpaper attached property for wallpapers

src/scriptengines/qml/plasmoid/appletinterface.cpp

@@ -59,7 +59,6 @@ AppletInterface::AppletInterface(DeclarativeAppletScript *script, QQuickItem *pa
       m_busy(false),
       m_hideOnDeactivate(true)
 {
-    qmlRegisterType<AppletInterface>();
     qmlRegisterType<QAction>();
 
     connect(this, &AppletInterface::configNeedsSaving,

src/scriptengines/qml/plasmoid/containmentinterface.cpp

@@ -59,8 +59,6 @@ ContainmentInterface::ContainmentInterface(DeclarativeAppletScript *parent)
 {
     setAcceptedMouseButtons(Qt::AllButtons);
 
-    qmlRegisterType<ContainmentInterface>();
-
     connect(containment(), &Plasma::Containment::appletRemoved,
             this, &ContainmentInterface::appletRemovedForward);
     connect(containment(), &Plasma::Containment::appletAdded,

src/scriptengines/qml/plasmoid/declarativeappletscript.cpp

@@ -42,6 +42,7 @@
 
 #include "plasmoid/appletinterface.h"
 #include "plasmoid/containmentinterface.h"
+#include "plasmoid/wallpaperinterface.h"
 
 #include <kdeclarative/qmlobject.h>
 #include <kdeclarative/configpropertymap.h>
@@ -60,6 +61,9 @@ DeclarativeAppletScript::DeclarativeAppletScript(QObject *parent, const QVariant
     qmlRegisterUncreatableType<ContainmentInterface>("org.kde.plasma.plasmoid", 2, 0, "Containment",
                                              QLatin1String("Do not create objects of type Containment"));
 
+    qmlRegisterUncreatableType<WallpaperInterface>("org.kde.plasma.plasmoid", 2, 0, "Wallpaper",
+                                             QLatin1String("Do not create objects of type Wallpaper"));
+
     qmlRegisterType<KDeclarative::ConfigPropertyMap>();
     Q_UNUSED(args);
 }

src/scriptengines/qml/plasmoid/wallpaperinterface.cpp

@@ -36,6 +36,8 @@
 #include <Plasma/ConfigLoader>
 #include <Plasma/PluginLoader>
 
+QHash<QObject *, WallpaperInterface *> WallpaperInterface::s_rootObjects = QHash<QObject *, WallpaperInterface *>();
+
 WallpaperInterface::WallpaperInterface(ContainmentInterface *parent)
     : QQuickItem(parent),
       m_containmentInterface(parent),
@@ -55,7 +57,9 @@ WallpaperInterface::WallpaperInterface(ContainmentInterface *parent)
 }
 
 WallpaperInterface::~WallpaperInterface()
-{}
+{
+    s_rootObjects.remove(m_qmlObject->engine());
+}
 
 KPluginInfo::List WallpaperInterface::listWallpaperInfoForMimetype(const QString &mimetype, const QString &formFactor)
 {
@@ -109,6 +113,7 @@ void WallpaperInterface::syncWallpaperPackage()
     
     if (!m_qmlObject) {
         m_qmlObject = new KDeclarative::QmlObject(this);
+        s_rootObjects[m_qmlObject->engine()] = this;
         m_qmlObject->setInitializationDelayed(true);
     }
 
@@ -142,6 +147,7 @@ void WallpaperInterface::syncWallpaperPackage()
 
     } else if (m_qmlObject->mainComponent()) {
         qWarning() << "Error loading the wallpaper" << m_qmlObject->mainComponent()->errors();
+        s_rootObjects.remove(m_qmlObject->engine());
         m_qmlObject->deleteLater();
         m_qmlObject = 0;
 

src/scriptengines/qml/plasmoid/wallpaperinterface.h

@@ -21,6 +21,7 @@
 #define WALLPAPERINTERFACE_H
 
 #include <QQuickItem>
+#include <QQmlEngine>
 
 #include <Plasma/Package>
 
@@ -78,6 +79,17 @@ public:
 
     Q_INVOKABLE QAction *action(QString name) const;
 
+    static WallpaperInterface *qmlAttachedProperties(QObject *object)
+    {
+        //at the moment of the attached object creation, the root item is the only one that hasn't a parent
+        //only way to avoid creation of this attached for everybody but the root item
+        if (!object->parent() && s_rootObjects.contains(QtQml::qmlEngine(object))) {
+            return s_rootObjects.value(QtQml::qmlEngine(object));
+        } else {
+            return 0;
+        }
+    }
+
 Q_SIGNALS:
     void packageChanged();
     void configurationChanged();
@@ -95,6 +107,10 @@ private:
     Plasma::ConfigLoader *m_configLoader;
     KActionCollection *m_actions;
     QSignalMapper *m_actionSignals;
+
+    static QHash<QObject *, WallpaperInterface *> s_rootObjects;
 };
 
+QML_DECLARE_TYPEINFO(WallpaperInterface, QML_HAS_ATTACHED_PROPERTIES)
+
 #endif