iOS: Fix QWindow::reportContentOrientationChange on iOS6+

On iOS 6 and above, [UIViewController supportedInterfaceOrientations]
needs to return 0 for [UIApplication setStatusBarOrientation] to work.

This means once you report a content orientation other than the primary
orientation, you'll disable auto-rotation. Reporting the orientation as
Qt::PrimaryOrientation restores the auto-rotation behavior.

Change-Id: I1b8c765c507728fdbc5b828e0b4215324014e221
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@theqtcompany.com>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@theqtcompany.com>

1 files changed, 80 insertions, 13 deletions

diff --git a/src/plugins/platforms/ios/qiosviewcontroller.mm b/src/plugins/platforms/ios/qiosviewcontroller.mm
index 8f59d41509..0afd2bf8ba 100644
--- a/src/plugins/platforms/ios/qiosviewcontroller.mm
+++ b/src/plugins/platforms/ios/qiosviewcontroller.mm
@@ -153,6 +153,7 @@
 #endif
 
         self.changingOrientation = NO;
+        self.shouldAutorotate = [super shouldAutorotate];
 
         // Status bar may be initially hidden at startup through Info.plist
         self.prefersStatusBarHidden = infoPlistValue(@"UIStatusBarHidden", false);
@@ -179,6 +180,10 @@
     [center addObserver:self selector:@selector(willChangeStatusBarFrame:)
             name:UIApplicationWillChangeStatusBarFrameNotification
             object:[UIApplication sharedApplication]];
+
+    [center addObserver:self selector:@selector(didChangeStatusBarOrientation:)
+            name:UIApplicationDidChangeStatusBarOrientationNotification
+            object:[UIApplication sharedApplication]];
 }
 
 - (void)viewDidUnload
@@ -189,19 +194,16 @@
 
 // -------------------------------------------------------------------------
 
--(BOOL)shouldAutorotate
-{
-    // Until a proper orientation and rotation API is in place, we always auto rotate.
-    // If auto rotation is not wanted, you would need to switch it off manually from Info.plist.
-    return YES;
-}
-
 #if QT_IOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__IPHONE_6_0)
 -(NSUInteger)supportedInterfaceOrientations
 {
-    // We need to tell iOS that we support all orientations in order to set
-    // status bar orientation when application content orientation changes.
-    return UIInterfaceOrientationMaskAll;
+    // As documented by Apple in the iOS 6.0 release notes, setStatusBarOrientation:animated:
+    // only works if the supportedInterfaceOrientations of the view controller is 0, making
+    // us responsible for ensuring that the status bar orientation is consistent. We enter
+    // this mode when auto-rotation is disabled due to an explicit content orientation being
+    // set on the focus window. Note that this is counter to what the documentation for
+    // supportedInterfaceOrientations says, which states that the method should not return 0.
+    return [self shouldAutorotate] ? UIInterfaceOrientationMaskAll : 0;
 }
 #endif
 
@@ -209,7 +211,7 @@
 -(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation
 {
     Q_UNUSED(interfaceOrientation);
-    return YES;
+    return [self shouldAutorotate];
 }
 #endif
 
@@ -256,6 +258,22 @@
     }];
 }
 
+- (void)didChangeStatusBarOrientation:(NSNotification *)notification
+{
+    Q_UNUSED(notification);
+
+    if (self.view.window.screen != [UIScreen mainScreen])
+        return;
+
+    // If the statusbar changes orientation due to auto-rotation we don't care,
+    // there will be re-layout anyways. Only if the statusbar changes due to
+    // reportContentOrientation, we need to update the window layout.
+    if (self.changingOrientation)
+        return;
+
+    [self.view setNeedsLayout];
+}
+
 - (void)viewWillLayoutSubviews
 {
     if (!QCoreApplication::instance())
@@ -287,6 +305,8 @@
     // All decisions are based on the the top level window
     focusWindow = qt_window_private(focusWindow)->topLevelWindow();
 
+    UIApplication *uiApplication = [UIApplication sharedApplication];
+
     bool currentStatusBarVisibility = self.prefersStatusBarHidden;
     self.prefersStatusBarHidden = focusWindow->windowState() == Qt::WindowFullScreen;
 
@@ -297,13 +317,60 @@
         } else
 #endif
         {
-            [[UIApplication sharedApplication]
-                setStatusBarHidden:self.prefersStatusBarHidden
+            [uiApplication setStatusBarHidden:self.prefersStatusBarHidden
                 withAnimation:self.preferredStatusBarUpdateAnimation];
         }
 
         [self.view setNeedsLayout];
     }
+
+
+    // -------------- Content orientation ---------------
+
+    static BOOL kAnimateContentOrientationChanges = YES;
+
+    Qt::ScreenOrientation contentOrientation = focusWindow->contentOrientation();
+    if (contentOrientation != Qt::PrimaryOrientation) {
+        // An explicit content orientation has been reported for the focus window,
+        // so we keep the status bar in sync with content orientation. This will ensure
+        // that the task bar (and associated gestures) are also rotated accordingly.
+
+        if (self.shouldAutorotate) {
+            // We are moving from Qt::PrimaryOrientation to an explicit orientation,
+            // so we need to store the current statusbar orientation, as we need it
+            // later when mapping screen coordinates for QScreen and for returning
+            // to Qt::PrimaryOrientation.
+            self.lockedOrientation = uiApplication.statusBarOrientation;
+
+            // Calling setStatusBarOrientation only has an effect when auto-rotation is
+            // disabled, which makes sense when there's an explicit content orientation.
+            self.shouldAutorotate = NO;
+        }
+
+        [uiApplication setStatusBarOrientation:
+            UIInterfaceOrientation(fromQtScreenOrientation(contentOrientation))
+            animated:kAnimateContentOrientationChanges];
+
+    } else {
+        // The content orientation is set to Qt::PrimaryOrientation, meaning
+        // that auto-rotation should be enabled. But we may be coming out of
+        // a state of locked orientation, which needs some cleanup before we
+        // can enable auto-rotation again.
+        if (!self.shouldAutorotate) {
+            // First we need to restore the statusbar to what it was at the
+            // time of locking the orientation, otherwise iOS will be very
+            // confused when it starts doing auto-rotation again.
+            [uiApplication setStatusBarOrientation:
+                UIInterfaceOrientation(self.lockedOrientation)
+                animated:kAnimateContentOrientationChanges];
+
+            // Then we can re-enable auto-rotation
+            self.shouldAutorotate = YES;
+
+            // And finally let iOS rotate the root view to match the device orientation
+            [UIViewController attemptRotationToDeviceOrientation];
+        }
+    }
 }
 
 #if QT_IOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__IPHONE_7_0)