Handling saving the changes of the KCM

Save method added to the EffectView which invokes the specific methods
on the effect model and compositing object.

kcmkwin/kwincompositing/main.cpp

@@ -36,6 +36,9 @@ public:
     explicit KWinCompositingKCM(QWidget* parent = 0, const QVariantList& args = QVariantList());
     virtual ~KWinCompositingKCM();
 
+public Q_SLOTS:
+    void save() override;
+
 private:
     QScopedPointer<KWin::Compositing::EffectView> m_view;
 };
@@ -64,6 +67,12 @@ KWinCompositingKCM::~KWinCompositingKCM()
 {
 }
 
+void KWinCompositingKCM::save()
+{
+    m_view->save();
+    KCModule::save();
+}
+
 K_PLUGIN_FACTORY(KWinCompositingConfigFactory,
                  registerPlugin<KWinCompositingKCM>();
                 )

kcmkwin/kwincompositing/model.cpp

@@ -375,5 +375,15 @@ void EffectView::init()
     connect(rootObject(), SIGNAL(changed()), this, SIGNAL(changed()));
 }
 
+void EffectView::save()
+{
+    if (auto *model = rootObject()->findChild<EffectFilterModel*>(QStringLiteral("filterModel"))) {
+        model->syncConfig();
+    }
+    if (auto *compositing = rootObject()->findChild<Compositing*>(QStringLiteral("compositing"))) {
+        compositing->save();
+    }
+}
+
 }//end namespace Compositing
 }//end namespace KWin

kcmkwin/kwincompositing/model.h

@@ -102,6 +102,8 @@ public:
 
     Q_INVOKABLE QColor backgroundViewColor() { return KColorScheme(QPalette::Active, KColorScheme::Window, KSharedConfigPtr(0)).background(KColorScheme::NormalBackground).color(); };
 
+    void save();
+
 Q_SIGNALS:
     void changed();
 private: