Por all usages of QWindop/windowHandle to KDDockWidgets::Window

Removes a lot of asQWidget() code and is also prepared for non-Qt
views.

src/qtquick/Platform_qtquick.cpp

@@ -13,17 +13,20 @@
 #include "KDDockWidgets.h"
 // #include "QmlTypes.h" // TODOv2
 
+#include "Window_qtquick.h"
 #include "views/View_qtquick.h"
+#include "qtquick/Window_qtquick.h"
+
 #include <QQuickWindow>
 #include <QGuiApplication>
 #include <QTimer>
+#include <QWindow>
 
 static KDDockWidgets::Platform_qtquick s_platformQtQuick;
 
 using namespace KDDockWidgets;
 
 
-
 Platform_qtquick::Platform_qtquick()
 {
     // KDDockWidgets::registerQmlTypes(); // TODOv2
@@ -61,3 +64,8 @@ std::shared_ptr<ViewWrapper> Platform_qtquick::qobjectAsView(QObject *obj) const
 
     return nullptr;
 }
+
+std::shared_ptr<Window> Platform_qtquick::windowFromQWindow(QWindow *qwindow) const
+{
+    return std::shared_ptr<Window>(new Window_qtquick(qwindow));
+}