Add View::setZOrder()

Only relevant to QtQuick.
Removes some ifdefs.

src/View.h

@@ -239,6 +239,9 @@ public:
     /// only the specific frontend can know what's the actual type
     virtual bool is(Type) const;
 
+    /// @brief Sets the z order
+    /// Not supported on all platforms
+    virtual void setZOrder(int) {};
 
     /// @brief if this view is a FloatingWindow, then returns its controller
     /// Mostly to save the call sites from having too many casts

src/controllers/DockWidget.cpp

@@ -932,16 +932,10 @@ void DockWidget::setMDISize(QSize size)
 
 void DockWidget::setMDIZ(int z)
 {
-#ifdef KDDOCKWIDGETS_QTQUICK
     if (Frame *frame = d->frame()) {
-        if (!frame->isMDI())
-            return;
-        frame->setZ(z);
+        if (frame->isMDI())
+            frame->view()->setZOrder(z);
     }
-#else
-    Q_UNUSED(z);
-    qWarning() << Q_FUNC_INFO << "Not implemented for QtQuick";
-#endif
 }
 
 bool DockWidget::isPersistentCentralDockWidget() const

src/qtquick/views/View_qtquick.cpp

@@ -821,4 +821,9 @@ QQuickItem *View_qtquick::createQQuickItem(const QString &filename, QQuickItem *
     return qquickitem;
 }
 
+void View_qtquick::setZOrder(int z)
+{
+    QQuickItem::setZ(z);
+}
+
 #include "View_qtquick.moc"

src/qtquick/views/View_qtquick.h

@@ -157,6 +157,7 @@ public:
     void setCursor(Qt::CursorShape shape) override;
     void setMouseTracking(bool enable) override;
     QVector<std::shared_ptr<View>> childViews() const override;
+    void setZOrder(int) override;
 
     /// @brief This is equivalent to "anchors.fill: parent but in C++
     void makeItemFillParent(QQuickItem *item);