iOS: Don't apply UIWindow safeAreInsets to available geometry on visionOS

There is no concept of a screen on visionOS, and hence no concept of
screen-relative system UI that we should keep top level windows away
from.

As UIWindow and UIScreen on visionOS report the exact same bounds, we
can't use the same code path we use for iOS/iPadOS to detect whether
to apply the safe area insets, so skip the logic entirely.

We still report the safe area insets on a QWindow level, so applications
can avoid rendering content close to UI elements such as the window
move and window close buttons.

Task-number: QTBUG-121781
Change-Id: I20ad02390564972a3715c27f351689b79ad579d8
Reviewed-by: Amr Elsayed <amr.elsayed@qt.io>
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

1 files changed, 20 insertions, 5 deletions

diff --git a/src/plugins/platforms/ios/qiosscreen.mm b/src/plugins/platforms/ios/qiosscreen.mm
index 6d38761d00..e48592aa24 100644
--- a/src/plugins/platforms/ios/qiosscreen.mm
+++ b/src/plugins/platforms/ios/qiosscreen.mm
@@ -296,6 +296,15 @@ QString QIOSScreen::name() const
         return "External display"_L1;
 }
 
+static bool isRunningOnVisionOS()
+{
+    static bool result = []{
+        // This class is documented to only be available on visionOS
+        return NSClassFromString(@"UIWindowSceneGeometryPreferencesVision");
+    }();
+    return result;
+}
+
 void QIOSScreen::updateProperties()
 {
     QRect previousGeometry = m_geometry;
@@ -308,11 +317,17 @@ void QIOSScreen::updateProperties()
     // For convenience, we reflect the safe area margins of the screen's UIWindow
     // by reducing the available geometry of the screen. But we only do this if
     // the UIWindow bounds is representative of the UIScreen.
-    UIEdgeInsets safeAreaInsets = m_uiWindow.safeAreaInsets;
-    if (m_uiWindow.bounds.size.width == m_uiScreen.bounds.size.width)
-        m_availableGeometry.adjust(safeAreaInsets.left, 0, -safeAreaInsets.right, 0);
-    if (m_uiWindow.bounds.size.height == m_uiScreen.bounds.size.height)
-        m_availableGeometry.adjust(0, safeAreaInsets.top, 0, -safeAreaInsets.bottom);
+    if (isRunningOnVisionOS()) {
+        // On visionOS there is no concept of a screen, and hence no concept of
+        // screen-relative system UI that we should keep top level windows away
+        // from, so don't apply the UIWindow safe area insets to the screen.
+    } else {
+        UIEdgeInsets safeAreaInsets = m_uiWindow.safeAreaInsets;
+        if (m_uiWindow.bounds.size.width == m_uiScreen.bounds.size.width)
+            m_availableGeometry.adjust(safeAreaInsets.left, 0, -safeAreaInsets.right, 0);
+        if (m_uiWindow.bounds.size.height == m_uiScreen.bounds.size.height)
+            m_availableGeometry.adjust(0, safeAreaInsets.top, 0, -safeAreaInsets.bottom);
+    }
 
 #ifndef Q_OS_TVOS
     if (m_uiScreen == [UIScreen mainScreen]) {