QNX: support underlain foreign windows

Previously, any foreign window was treated as an overlay, with its
z-order being forcibly set above the native Qt windows.

This change adjusts the strategy to treat foreign windows whose initial
z-order is less than -1 (the default z-order used by mmrender for its
overlay surfaces) as underlays; otherwise the foreign window is treated
as an overlay.

Change-Id: Ifbcfd3a956965fa1a347076e9845afa50a81edfd
Reviewed-by: Thomas McGuire <thomas.mcguire@kdab.com>
Reviewed-by: Kevin Krammer <kevin.krammer@kdab.com>
Reviewed-by: Rafael Roquetto <rafael.roquetto@kdab.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/plugins/platforms/qnx/qqnxscreen.h b/src/plugins/platforms/qnx/qqnxscreen.h
index 98f2a90fbc..6e8c2c6a60 100644
--- a/src/plugins/platforms/qnx/qqnxscreen.h
+++ b/src/plugins/platforms/qnx/qqnxscreen.h
@@ -114,7 +114,8 @@ private:
     void resizeTopLevelWindow(QQnxWindow *w, const QRect &previousScreenGeometry) const;
     void resizeWindows(const QRect &previousScreenGeometry);
     void addOverlayWindow(screen_window_t window);
-    void removeOverlayWindow(screen_window_t window);
+    void addUnderlayWindow(screen_window_t window);
+    void removeOverlayOrUnderlayWindow(screen_window_t window);
 
     QWindow *topMostChildWindow() const;
 
@@ -136,6 +137,7 @@ private:
 
     QList<QQnxWindow *> m_childWindows;
     QList<screen_window_t> m_overlays;
+    QList<screen_window_t> m_underlays;
 
     QPlatformCursor *m_cursor;
 };