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>

1 files changed, 11 insertions, 8 deletions

diff --git a/src/plugins/platforms/ios/qiosintegration.mm b/src/plugins/platforms/ios/qiosintegration.mm
index c646042eb2..7cd21f83f6 100644
--- a/src/plugins/platforms/ios/qiosintegration.mm
+++ b/src/plugins/platforms/ios/qiosintegration.mm
@@ -9,7 +9,7 @@
 #include "qioswindow.h"
 #include "qiosscreen.h"
 #include "qiosplatformaccessibility.h"
-#ifndef Q_OS_TVOS
+#if QT_CONFIG(clipboard)
 #include "qiosclipboard.h"
 #endif
 #include "qiosinputcontext.h"
@@ -51,7 +51,7 @@ QIOSIntegration *QIOSIntegration::instance()
 
 QIOSIntegration::QIOSIntegration()
     : m_fontDatabase(new QCoreTextFontDatabaseEngineFactory<QCoreTextFontEngine>)
-#if !defined(Q_OS_TVOS) && !defined(QT_NO_CLIPBOARD)
+#if QT_CONFIG(clipboard)
     , m_clipboard(new QIOSClipboard)
 #endif
     , m_inputContext(0)
@@ -72,6 +72,10 @@ QIOSIntegration::QIOSIntegration()
 
 void QIOSIntegration::initialize()
 {
+#if defined(Q_OS_VISIONOS)
+    // Qt requires a screen, so let's give it a dummy one
+    QWindowSystemInterface::handleScreenAdded(new QIOSScreen);
+#else
     UIScreen *mainScreen = [UIScreen mainScreen];
     NSMutableArray<UIScreen *> *screens = [[[UIScreen screens] mutableCopy] autorelease];
     if (![screens containsObject:mainScreen]) {
@@ -81,6 +85,7 @@ void QIOSIntegration::initialize()
 
     for (UIScreen *screen in screens)
         QWindowSystemInterface::handleScreenAdded(new QIOSScreen(screen));
+#endif
 
     // Depends on a primary screen being present
     m_inputContext = new QIOSInputContext;
@@ -88,8 +93,10 @@ void QIOSIntegration::initialize()
     m_touchDevice = new QPointingDevice;
     m_touchDevice->setType(QInputDevice::DeviceType::TouchScreen);
     QPointingDevice::Capabilities touchCapabilities = QPointingDevice::Capability::Position | QPointingDevice::Capability::NormalizedPosition;
+#if !defined(Q_OS_VISIONOS)
     if (mainScreen.traitCollection.forceTouchCapability == UIForceTouchCapabilityAvailable)
         touchCapabilities |= QPointingDevice::Capability::Pressure;
+#endif
     m_touchDevice->setCapabilities(touchCapabilities);
     QWindowSystemInterface::registerInputDevice(m_touchDevice);
 #if QT_CONFIG(tabletevent)
@@ -107,7 +114,7 @@ QIOSIntegration::~QIOSIntegration()
     delete m_fontDatabase;
     m_fontDatabase = 0;
 
-#if !defined(Q_OS_TVOS) && !defined(QT_NO_CLIPBOARD)
+#if QT_CONFIG(clipboard)
     delete m_clipboard;
     m_clipboard = 0;
 #endif
@@ -208,14 +215,10 @@ QPlatformFontDatabase * QIOSIntegration::fontDatabase() const
     return m_fontDatabase;
 }
 
-#ifndef QT_NO_CLIPBOARD
+#if QT_CONFIG(clipboard)
 QPlatformClipboard *QIOSIntegration::clipboard() const
 {
-#ifndef Q_OS_TVOS
     return m_clipboard;
-#else
-    return QPlatformIntegration::clipboard();
-#endif
 }
 #endif