macOS: lower the splash screen when a modal dialog blocks it

This fixes the usability issue of a modal dialog showing up behind a
splash screen, not visible to the user, but blocking user input and the
application startup sequence until discarded.

[ChangeLog][QtWidgets][QSlashScreen] On macOS, lower the splash screen
when a modal dialog is shown to make sure the user sees the dialog.

Change-Id: Ibae768f76909d930cb25dcf5cee31edc5f15c29a
Fixes: QTBUG-49576
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
 
 

1 files changed, 19 insertions, 0 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 232c74b1e9..b5d63f8331 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -217,6 +217,25 @@ QCocoaIntegration::QCocoaIntegration(const QStringList &paramList)
 
     connect(qGuiApp, &QGuiApplication::focusWindowChanged,
         this, &QCocoaIntegration::focusWindowChanged);
+
+    static auto splashScreenHider = QMacKeyValueObserver(NSApp, @"modalWindow", []{
+        const QWindowList allWindows = QGuiApplication::topLevelWindows();
+        for (QWindow *window : allWindows) {
+            if ((window->flags() & Qt::SplashScreen) == Qt::SplashScreen) {
+                QCocoaWindow *platformWindow = static_cast<QCocoaWindow*>(window->handle());
+                NSWindow *splashWindow = platformWindow->view().window;
+                if (!splashWindow)
+                    continue;
+                if (NSApp.modalWindow) {
+                    NSInteger originalLevel = splashWindow.level;
+                    splashWindow.level = NSNormalWindowLevel;
+                    window->setProperty("_q_levelBeforeModalSession", (qlonglong)originalLevel);
+                } else if (NSInteger originalLevel = window->property("_q_levelBeforeModalSession").toLongLong()) {
+                    splashWindow.level = originalLevel;
+                }
+            }
+        }
+    });
 }
 
 QCocoaIntegration::~QCocoaIntegration()