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

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

src/qtcommon/Window_qt.cpp

@@ -13,14 +13,92 @@
 #include "Window_qt.h"
 
 #include <QWindow>
+#include <QScreen>
 
 using namespace KDDockWidgets;
 
 Window_qt::Window_qt(QWindow *window)
     : m_window(window)
 {
+    m_connection = QObject::connect(window, &QWindow::screenChanged, [this] {
+        screenChanged.emit();
+    });
 }
 
 Window_qt::~Window_qt()
 {
+    QObject::disconnect(m_connection);
+}
+
+void Window_qt::setWindowState(Qt::WindowState state)
+{
+    m_window->setWindowState(state);
+}
+
+Qt::WindowState Window_qt::windowState() const
+{
+    return m_window->windowState();
+}
+
+QRect Window_qt::geometry() const
+{
+    return m_window->geometry();
+}
+
+void Window_qt::setProperty(const char *name, const QVariant &value)
+{
+    m_window->setProperty(name, value);
+}
+
+bool Window_qt::isVisible() const
+{
+    return m_window->isVisible();
+}
+
+WId Window_qt::handle() const
+{
+    if (m_window->handle())
+        return m_window->winId();
+    return 0;
+}
+
+QWindow *Window_qt::qtWindow() const
+{
+    return m_window;
+}
+
+bool Window_qt::equals(std::shared_ptr<Window> other) const
+{
+    auto otherQt = static_cast<Window_qt *>(other.get());
+    return other && otherQt->m_window == m_window;
+}
+
+void Window_qt::setFramePosition(QPoint targetPos)
+{
+    m_window->setFramePosition(targetPos);
+}
+
+void Window_qt::setPosition(QPoint targetPos)
+{
+    m_window->setFramePosition(targetPos);
+}
+
+QRect Window_qt::frameGeometry() const
+{
+    return m_window->frameGeometry();
+}
+
+void Window_qt::resize(int width, int height)
+{
+    m_window->resize(width, height);
+}
+
+bool Window_qt::isActive() const
+{
+    return m_window->isActive();
+}
+
+QSize Window_qt::size() const
+{
+    return m_window->size();
 }