re-add Corona::createContainmentDelayed()

unfortunate, but necessary for on the fly containment plugin switch

src/plasma/corona.cpp

@@ -198,6 +198,15 @@ Containment *Corona::createContainment(const QString &name, const QVariantList &
     return 0;
 }
 
+Containment *Corona::createContainmentDelayed(const QString &name, const QVariantList &args)
+{
+    if (d->immutability == Types::Mutable) {
+        return d->addContainment(name, args, 0, true);
+    }
+
+    return 0;
+}
+
 int Corona::screenForContainment(const Containment* containment) const
 {
     return -1;
@@ -388,7 +397,7 @@ void CoronaPrivate::syncConfig()
     emit q->configSynced();
 }
 
-Containment *CoronaPrivate::addContainment(const QString &name, const QVariantList &args, uint id)
+Containment *CoronaPrivate::addContainment(const QString &name, const QVariantList &args, uint id, bool delayedInit)
 {
     QString pluginName = name;
     Containment *containment = 0;
@@ -448,14 +457,16 @@ Containment *CoronaPrivate::addContainment(const QString &name, const QVariantLi
     QObject::connect(containment, SIGNAL(screenChanged(int)),
             q, SIGNAL(screenOwnerChanged(int)));
 
-    containment->init();
-    KConfigGroup cg = containment->config();
-    containment->restore(cg);
-    containment->updateConstraints(Plasma::Types::StartupCompletedConstraint);
-    containment->save(cg);
-    q->requestConfigSync();
-    containment->flushPendingConstraintsEvents();
-    emit q->containmentAdded(containment);
+    if (!delayedInit) {
+        containment->init();
+        KConfigGroup cg = containment->config();
+        containment->restore(cg);
+        containment->updateConstraints(Plasma::Types::StartupCompletedConstraint);
+        containment->save(cg);
+        q->requestConfigSync();
+        containment->flushPendingConstraintsEvents();
+        emit q->containmentAdded(containment);
+    }
 
     return containment;
 }

src/plasma/corona.h

@@ -271,6 +271,26 @@ protected:
      **/
     virtual void loadDefaultLayout();
 
+    /**
+     * Loads a containment with delayed initialization, primarily useful
+     * for implementations of loadDefaultLayout. The caller is responsible
+     * for all initializating, saving and notification of a new containment.
+     *
+     * @param name the plugin name for the containment, as given by
+     *        KPluginInfo::pluginName(). If an empty string is passed in, the defalt
+     *        containment plugin will be used (usually DesktopContainment). If the
+     *        string literal "null" is passed in, then no plugin will be loaded and
+     *        a simple Containment object will be created instead.
+     * @param args argument list to pass to the containment
+     *
+     * @return a pointer to the containment on success, or 0 on failure. Failure can
+     * be caused by the Immutability type being too restrictive, as containments can't be added
+     * when widgets are locked, or if the requested containment plugin can not be located
+     * or successfully loaded.
+     * @see addContainment
+     **/
+    Containment *createContainmentDelayed(const QString &name,
+                                          const QVariantList &args = QVariantList());
 private:
     CoronaPrivate *const d;
 

src/plasma/private/corona_p.h

@@ -45,7 +45,7 @@ public:
     void updateContainmentImmutability();
     void containmentDestroyed(QObject *obj);
     void syncConfig();
-    Containment *addContainment(const QString &name, const QVariantList &args, uint id);
+    Containment *addContainment(const QString &name, const QVariantList &args, uint id, bool delayedInit = false);
     QList<Plasma::Containment *> importLayout(const KConfigGroup &conf, bool mergeConfig);
 
     Corona *q;

src/scriptengines/qml/plasmoid/containmentinterface.cpp

@@ -148,6 +148,10 @@ void ContainmentInterface::init()
         QQmlProperty prop(qmlObject()->rootObject(), "anchors.fill");
         prop.write(expr.evaluate());
     }
+
+    if (!containment()->wallpaper().isEmpty()) {
+        loadWallpaper();
+    }
 }
 
 QList <QObject *> ContainmentInterface::applets()

src/scriptengines/qml/plasmoid/wallpaperinterface.cpp

@@ -110,12 +110,13 @@ Plasma::ConfigLoader *WallpaperInterface::configScheme()
 
 void WallpaperInterface::syncWallpaperPackage()
 {
-    if (m_wallpaperPlugin == m_containmentInterface->containment()->wallpaper()) {
+    if (m_wallpaperPlugin == m_containmentInterface->containment()->wallpaper() &&
+        m_qmlObject->rootObject()) {
         return;
     }
 
     m_wallpaperPlugin = m_containmentInterface->containment()->wallpaper();
-    
+
     if (!m_qmlObject) {
         m_qmlObject = new KDeclarative::QmlObject(this);
         s_rootObjects[m_qmlObject->engine()] = this;
@@ -138,7 +139,6 @@ void WallpaperInterface::syncWallpaperPackage()
         m_configuration = new KDeclarative::ConfigPropertyMap(configScheme(), this);
     }
 
-    
     m_qmlObject->setSource(QUrl::fromLocalFile(m_pkg.filePath("mainscript")));
     m_qmlObject->engine()->rootContext()->setContextProperty("wallpaper", this);
     m_qmlObject->completeInitialization();