winrt: Refactor platform plugin for XAML support

By using XAML as the platform compositor, many benefits are possible:
 - Better input context handling for tablets
 - Better multiple window support (including non-fullscreen windows)
 - Support for transparent windows and window opacity
 - Integration with native platform controls
 - Simpler orientation handling on Windows Phone with built-in transitions

This patch applies only the minimal parts to make XAML mode work just as
the raw D3D mode. It does this by:
 - Moving all OpenGL parts into QWinRTEGLContext. This will allow us to
   have non-OpenGL windows later (e.g. Direct2D raster surfaces).
 - Moving more window-specific parts into QWinRTWindow. Each window creates
   a SwapChainPanel which can then be used for ANGLE (or Direct2D) content.
 - Moving non screen-specific parts into QWinRTIntegration.
 - Having QWinRTScreen create the base XAML element Canvas.
 - Running certain calls on the UI thread where necessary.

The following code parts were removed:
 - The UIAutomationCore code in QWinRTInputContext, as this is incompatible
   with XAML automation.
 - The D3D Trim and device blacklist, as these have been fixed in ANGLE.
 - Core dispatcher processing in QEventDispatcherWinRT. Now there is only
   one native event dispatcher; it is always running and never needs to be
   pumped.

Future commits should address:
 - Maintaining the window stack list and visibility using the XAML Canvas.
 - Allowing for windows (e.g. popups) to be sized and positioned instead
   of fullscreen.
 - Using the XAML automation API to improve the platform input context.

[ChangeLog][QPA][winrt] Windows Store apps are now composited inside a
XAML container, allowing for tighter integration with the native UI layer.

Change-Id: I285c6dea657c5dab2fda2b1bd8e8e5dd15882c72
Reviewed-by: Oliver Wolff <oliver.wolff@theqtcompany.com>

1 files changed, 5 insertions, 3 deletions

diff --git a/src/plugins/platforms/winrt/qwinrtwindow.h b/src/plugins/platforms/winrt/qwinrtwindow.h
index 3cfe346ab2..88c149b080 100644
--- a/src/plugins/platforms/winrt/qwinrtwindow.h
+++ b/src/plugins/platforms/winrt/qwinrtwindow.h
@@ -42,8 +42,7 @@
 
 QT_BEGIN_NAMESPACE
 
-class QWinRTScreen;
-
+class QWinRTWindowPrivate;
 class QWinRTWindow : public QPlatformWindow
 {
 public:
@@ -59,10 +58,13 @@ public:
     void raise();
     void lower();
 
+    WId winId() const Q_DECL_OVERRIDE;
+
     qreal devicePixelRatio() const Q_DECL_OVERRIDE;
 
 private:
-    QWinRTScreen *m_screen;
+    QScopedPointer<QWinRTWindowPrivate> d_ptr;
+    Q_DECLARE_PRIVATE(QWinRTWindow)
 };
 
 QT_END_NAMESPACE