Add preliminary support for Qt for visionOS

Qt already runs on Vision Pro as "Designed for iPad", using Qt
for iOS. This change enables building Qt for visionOS directly,
which opens the door to visionOS specific APIs and use-cases
such as volumes and immersive spaces.

The platform removes some APIs we depend on, notably UIScreen,
so some code paths have been disabled or mocked to get something
up and running.

As our current window management approach on UIKit platforms
depends on UIWindow and UIScreen there is currently no way to
bring up QWindows. This will improve once we refactor our
window management to use window scenes.

To configure for visionOS, pass -platform macx-visionos-clang,
and optionally add -sdk xrsimulator to build for the simulator.

Change-Id: I4eda55fc3fd06e12d30a188928487cf68940ee07
Reviewed-by:  Alexey Edelev <alexey.edelev@qt.io>

8 files changed, 21 insertions, 24 deletions

diff --git a/src/gui/CMakeLists.txt b/src/gui/CMakeLists.txt
index 87621e4c68..cef71318d8 100644
--- a/src/gui/CMakeLists.txt
+++ b/src/gui/CMakeLists.txt
@@ -13,7 +13,7 @@ if (QT_FEATURE_gui)
         set(_default_platform "android")
     elseif(MACOS)
         set(_default_platform "cocoa")
-    elseif(TVOS OR IOS)
+    elseif(UIKIT)
         set(_default_platform "ios")
     elseif(WATCHOS)
         set(_default_platform "minimal")
diff --git a/src/gui/configure.cmake b/src/gui/configure.cmake
index ddb0af35b6..e1d8efb292 100644
--- a/src/gui/configure.cmake
+++ b/src/gui/configure.cmake
@@ -813,7 +813,7 @@ qt_feature("vulkan" PUBLIC
 )
 qt_feature("metal" PUBLIC
     LABEL "Metal"
-    CONDITION MACOS OR IOS
+    CONDITION MACOS OR IOS OR VISIONOS
 )
 qt_feature("vkkhrdisplay" PRIVATE
     SECTION "Platform plugins"
@@ -1255,6 +1255,7 @@ qt_feature("wayland" PUBLIC
     LABEL "Wayland"
     CONDITION TARGET Wayland::Client
 )
+
 qt_configure_add_summary_section(NAME "Qt Gui")
 qt_configure_add_summary_entry(ARGS "accessibility")
 qt_configure_add_summary_entry(ARGS "freetype")
@@ -1371,7 +1372,7 @@ qt_configure_add_report_entry(
 qt_configure_add_report_entry(
     TYPE ERROR
     MESSAGE "The OpenGL functionality tests failed! You might need to modify the OpenGL package search path by setting the OpenGL_DIR CMake variable to the OpenGL library's installation directory."
-    CONDITION QT_FEATURE_gui AND NOT WATCHOS AND ( NOT INPUT_opengl STREQUAL 'no' ) AND NOT QT_FEATURE_opengl_desktop AND NOT QT_FEATURE_opengles2 AND NOT QT_FEATURE_opengl_dynamic
+    CONDITION QT_FEATURE_gui AND NOT WATCHOS AND NOT VISIONOS AND ( NOT INPUT_opengl STREQUAL 'no' ) AND NOT QT_FEATURE_opengl_desktop AND NOT QT_FEATURE_opengles2 AND NOT QT_FEATURE_opengl_dynamic
 )
 qt_configure_add_report_entry(
     TYPE WARNING
diff --git a/src/gui/painting/qcoregraphics.mm b/src/gui/painting/qcoregraphics.mm
index 7b64106323..27b46202f5 100644
--- a/src/gui/painting/qcoregraphics.mm
+++ b/src/gui/painting/qcoregraphics.mm
@@ -185,7 +185,7 @@ QPixmap qt_mac_toQPixmap(const NSImage *image, const QSizeF &size)
 
 #endif // Q_OS_MACOS
 
-#ifdef Q_OS_IOS
+#ifdef QT_PLATFORM_UIKIT
 
 QImage qt_mac_toQImage(const UIImage *image, QSizeF size)
 {
@@ -202,7 +202,7 @@ QImage qt_mac_toQImage(const UIImage *image, QSizeF size)
     return ret;
 }
 
-#endif // Q_OS_IOS
+#endif // QT_PLATFORM_UIKIT
 
 // ---------------------- Colors and Brushes ----------------------
 
diff --git a/src/gui/painting/qcoregraphics_p.h b/src/gui/painting/qcoregraphics_p.h
index f2c2ba1db1..a35f27a730 100644
--- a/src/gui/painting/qcoregraphics_p.h
+++ b/src/gui/painting/qcoregraphics_p.h
@@ -26,10 +26,8 @@
 #if defined(__OBJC__)
 # if defined(Q_OS_MACOS)
 #  include <AppKit/AppKit.h>
-#  define HAVE_APPKIT
-# elif defined(Q_OS_IOS)
+# elif defined(QT_PLATFORM_UIKIT)
 #  include <UIKit/UIKit.h>
-#  define HAVE_UIKIT
 # endif
 #endif
 
@@ -37,11 +35,11 @@ QT_BEGIN_NAMESPACE
 
 Q_GUI_EXPORT CGBitmapInfo qt_mac_bitmapInfoForImage(const QImage &image);
 
-#ifdef HAVE_UIKIT
+#ifdef QT_PLATFORM_UIKIT
 Q_GUI_EXPORT QImage qt_mac_toQImage(const UIImage *image, QSizeF size);
 #endif
 
-#ifdef HAVE_APPKIT
+#ifdef Q_OS_MACOS
 Q_GUI_EXPORT QPixmap qt_mac_toQPixmap(const NSImage *image, const QSizeF &size);
 
 QT_END_NAMESPACE
@@ -66,7 +64,7 @@ Q_GUI_EXPORT void qt_mac_drawCGImage(CGContextRef inContext, const CGRect *inBou
 
 Q_GUI_EXPORT void qt_mac_clip_cg(CGContextRef hd, const QRegion &rgn, CGAffineTransform *orig_xform);
 
-#ifdef HAVE_APPKIT
+#ifdef Q_OS_MACOS
 Q_GUI_EXPORT QColor qt_mac_toQColor(const NSColor *color);
 Q_GUI_EXPORT QBrush qt_mac_toQBrush(const NSColor *color, QPalette::ColorGroup colorGroup = QPalette::Normal);
 #endif
@@ -90,6 +88,4 @@ private:
 
 QT_END_NAMESPACE
 
-#undef HAVE_APPKIT
-
 #endif // QCOREGRAPHICS_P_H
diff --git a/src/gui/platform/darwin/qappleiconengine.mm b/src/gui/platform/darwin/qappleiconengine.mm
index 8300222dea..7e0ed184dc 100644
--- a/src/gui/platform/darwin/qappleiconengine.mm
+++ b/src/gui/platform/darwin/qappleiconengine.mm
@@ -5,7 +5,7 @@
 
 #if defined(Q_OS_MACOS)
 # include <AppKit/AppKit.h>
-#elif defined (Q_OS_IOS)
+#elif defined(QT_PLATFORM_UIKIT)
 # include <UIKit/UIKit.h>
 #endif
 
@@ -280,7 +280,7 @@ auto *loadImage(const QString &iconName)
     NSString *systemIconName = it != std::end(iconMap) ? it->second : iconName.toNSString();
 #if defined(Q_OS_MACOS)
     return [NSImage imageWithSystemSymbolName:systemIconName accessibilityDescription:nil];
-#elif defined(Q_OS_IOS)
+#elif defined(QT_PLATFORM_UIKIT)
     return [UIImage systemImageNamed:systemIconName];
 #endif
 }
@@ -374,7 +374,7 @@ auto *configuredImage(const NSImage *image, const QColor &color)
 
     return [image imageWithSymbolConfiguration:config];
 }
-#elif defined(Q_OS_IOS)
+#elif defined(QT_PLATFORM_UIKIT)
 auto *configuredImage(const UIImage *image, const QColor &color)
 {
     auto *config = [UIImageSymbolConfiguration configurationWithPointSize:48
@@ -453,7 +453,7 @@ void QAppleIconEngine::paint(QPainter *painter, const QRect &rect, QIcon::Mode m
 
     [image drawInRect:iconRect fromRect:sourceRect operation:NSCompositingOperationSourceOver fraction:1.0 respectFlipped:YES hints:nil];
     [NSGraphicsContext restoreGraphicsState];
-#elif defined(Q_OS_IOS)
+#elif defined(QT_PLATFORM_UIKIT)
     UIGraphicsPushContext(ctx);
     const CGRect cgrect = CGRectMake(rect.x(), rect.y(), rect.width(), rect.height());
     [image drawInRect:cgrect];
diff --git a/src/gui/platform/darwin/qappleiconengine_p.h b/src/gui/platform/darwin/qappleiconengine_p.h
index 8f48e8e6fc..2a4ff7fc64 100644
--- a/src/gui/platform/darwin/qappleiconengine_p.h
+++ b/src/gui/platform/darwin/qappleiconengine_p.h
@@ -51,7 +51,7 @@ private:
     const QString m_iconName;
 #if defined(Q_OS_MACOS)
     const NSImage *m_image;
-#elif defined(Q_OS_IOS)
+#elif defined(QT_PLATFORM_UIKIT)
     const UIImage *m_image;
 #endif
     mutable QPixmap m_pixmap;
diff --git a/src/gui/rhi/qrhimetal.mm b/src/gui/rhi/qrhimetal.mm
index e10da4ca0e..1c7b397193 100644
--- a/src/gui/rhi/qrhimetal.mm
+++ b/src/gui/rhi/qrhimetal.mm
@@ -567,9 +567,7 @@ bool QRhiMetal::create(QRhi::Flags flags)
     // suitable as deviceId because it does not seem stable on macOS and can
     // apparently change when the system is rebooted.
 
-#ifdef Q_OS_IOS
-    driverInfoStruct.deviceType = QRhiDriverInfo::IntegratedDevice;
-#else
+#ifdef Q_OS_MACOS
     if (@available(macOS 10.15, *)) {
         const MTLDeviceLocation deviceLocation = [d->dev location];
         switch (deviceLocation) {
@@ -586,6 +584,8 @@ bool QRhiMetal::create(QRhi::Flags flags)
             break;
         }
     }
+#else
+    driverInfoStruct.deviceType = QRhiDriverInfo::IntegratedDevice;
 #endif
 
     const QOperatingSystemVersion ver = QOperatingSystemVersion::current();
@@ -6465,12 +6465,12 @@ QRhiSwapChainHdrInfo QMetalSwapChain::hdrInfo()
 
     if (m_window) {
         // Must use m_window, not window, given this may be called before createOrResize().
-#ifdef Q_OS_MACOS
+#if defined(Q_OS_MACOS)
         NSView *view = reinterpret_cast<NSView *>(m_window->winId());
         NSScreen *screen = view.window.screen;
         info.limits.colorComponentValue.maxColorComponentValue = screen.maximumExtendedDynamicRangeColorComponentValue;
         info.limits.colorComponentValue.maxPotentialColorComponentValue = screen.maximumPotentialExtendedDynamicRangeColorComponentValue;
-#else
+#elif defined(Q_OS_IOS)
         if (@available(iOS 16.0, *)) {
             UIView *view = reinterpret_cast<UIView *>(m_window->winId());
             UIScreen *screen = view.window.windowScene.screen;
diff --git a/src/gui/text/coretext/qcoretextfontdatabase.mm b/src/gui/text/coretext/qcoretextfontdatabase.mm
index 3e058ec25f..19f3a2b335 100644
--- a/src/gui/text/coretext/qcoretextfontdatabase.mm
+++ b/src/gui/text/coretext/qcoretextfontdatabase.mm
@@ -896,7 +896,7 @@ static CTFontDescriptorRef fontDescriptorFromTheme(QPlatformTheme::Font f)
         UIFontDescriptor *desc = [UIFontDescriptor preferredFontDescriptorWithTextStyle:textStyle];
         return static_cast<CTFontDescriptorRef>(CFBridgingRetain(desc));
     }
-#endif // Q_OS_IOS, Q_OS_TVOS, Q_OS_WATCHOS
+#endif // QT_PLATFORM_UIKIT
 
     // macOS default case and iOS fallback case
     return descriptorForFontType(fontTypeFromTheme(f));