iOS: Fade out statusbar when scrolling view due to VKB

Change-Id: I86923a2b2aa2d17d79ba3a11cabf37e615eaf4cc
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

src/plugins/platforms/ios/qiosinputcontext.mm

@@ -399,6 +399,8 @@ void QIOSInputContext::scroll(int y)
             animation.toValue = [NSValue valueWithCATransform3D:translationTransform];
             [rootView.layer addAnimation:animation forKey:@"AnimateSubLayerTransform"];
             rootView.layer.sublayerTransform = translationTransform;
+
+            [rootView.qtViewController updateProperties];
         }
         completion:^(BOOL){
             if (self)

src/plugins/platforms/ios/qiosviewcontroller.h

@@ -41,6 +41,7 @@ class QIOSScreen;
 
 @property (nonatomic, assign) BOOL changingOrientation;
 @property (nonatomic, assign) BOOL prefersStatusBarHidden;
+@property (nonatomic, assign) UIStatusBarAnimation preferredStatusBarUpdateAnimation;
 
 - (id)initWithQIOSScreen:(QIOSScreen *)screen;
 - (void)updateProperties;

src/plugins/platforms/ios/qiosviewcontroller.mm

@@ -150,6 +150,7 @@
 
         // Status bar may be initially hidden at startup through Info.plist
         self.prefersStatusBarHidden = infoPlistValue(@"UIStatusBarHidden", false);
+        self.preferredStatusBarUpdateAnimation = UIStatusBarAnimationNone;
 
         QObject::connect(qApp, &QGuiApplication::focusWindowChanged, [self]() {
             [self updateProperties];
@@ -182,47 +183,6 @@
 
 // -------------------------------------------------------------------------
 
-- (void)updateProperties
-{
-    if (!isQtApplication())
-        return;
-
-    QWindow *focusWindow = QGuiApplication::focusWindow();
-
-    // If we don't have a focus window we leave the statusbar
-    // as is, so that the user can activate a new window with
-    // the same window state without the status bar jumping
-    // back and forth.
-    if (!focusWindow)
-        return;
-
-    // We only care about changes to focusWindow that involves our screen
-    if (!focusWindow->screen() || focusWindow->screen()->handle() != m_screen)
-        return;
-
-    // All decisions are based on the the top level window
-    focusWindow = qt_window_private(focusWindow)->topLevelWindow();
-
-    bool currentStatusBarVisibility = self.prefersStatusBarHidden;
-    self.prefersStatusBarHidden = focusWindow->windowState() == Qt::WindowFullScreen;
-    if (self.prefersStatusBarHidden != currentStatusBarVisibility) {
-#if QT_IOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__IPHONE_7_0)
-        if (QSysInfo::MacintoshVersion >= QSysInfo::MV_IOS_7_0) {
-            [self setNeedsStatusBarAppearanceUpdate];
-        } else
-#endif
-        {
-            [[UIApplication sharedApplication]
-                setStatusBarHidden:self.prefersStatusBarHidden
-                withAnimation:UIStatusBarAnimationNone];
-        }
-
-        [self.view setNeedsLayout];
-    }
-}
-
-// -------------------------------------------------------------------------
-
 -(BOOL)shouldAutorotate
 {
     // Until a proper orientation and rotation API is in place, we always auto rotate.
@@ -298,6 +258,54 @@
     m_screen->updateProperties();
 }
 
+// -------------------------------------------------------------------------
+
+- (void)updateProperties
+{
+    if (!isQtApplication())
+        return;
+
+    QWindow *focusWindow = QGuiApplication::focusWindow();
+
+    // If we don't have a focus window we leave the statusbar
+    // as is, so that the user can activate a new window with
+    // the same window state without the status bar jumping
+    // back and forth.
+    if (!focusWindow)
+        return;
+
+    // We only care about changes to focusWindow that involves our screen
+    if (!focusWindow->screen() || focusWindow->screen()->handle() != m_screen)
+        return;
+
+    // All decisions are based on the the top level window
+    focusWindow = qt_window_private(focusWindow)->topLevelWindow();
+
+    bool hasScrolledRootViewDueToVirtualKeyboard =
+        !CATransform3DIsIdentity(self.view.layer.sublayerTransform);
+
+    bool currentStatusBarVisibility = self.prefersStatusBarHidden;
+    self.prefersStatusBarHidden = focusWindow->windowState() == Qt::WindowFullScreen
+                                    || hasScrolledRootViewDueToVirtualKeyboard;
+    self.preferredStatusBarUpdateAnimation = hasScrolledRootViewDueToVirtualKeyboard ?
+        UIStatusBarAnimationFade : UIStatusBarAnimationNone;
+
+    if (self.prefersStatusBarHidden != currentStatusBarVisibility) {
+#if QT_IOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__IPHONE_7_0)
+        if (QSysInfo::MacintoshVersion >= QSysInfo::MV_IOS_7_0) {
+            [self setNeedsStatusBarAppearanceUpdate];
+        } else
+#endif
+        {
+            [[UIApplication sharedApplication]
+                setStatusBarHidden:self.prefersStatusBarHidden
+                withAnimation:self.preferredStatusBarUpdateAnimation];
+        }
+
+        [self.view setNeedsLayout];
+    }
+}
+
 #if QT_IOS_PLATFORM_SDK_EQUAL_OR_ABOVE(__IPHONE_7_0)
 - (UIStatusBarStyle)preferredStatusBarStyle
 {