[ios] remove layout guide observers

1 files changed, 44 insertions, 56 deletions

diff --git a/platform/ios/src/MGLMapView.mm b/platform/ios/src/MGLMapView.mm
index ed989459f5..39a9281a7a 100644
--- a/platform/ios/src/MGLMapView.mm
+++ b/platform/ios/src/MGLMapView.mm
@@ -656,21 +656,57 @@ public:
     _isWaitingForRedundantReachableNotification = NO;
 }
 
-- (void)dealloc
+- (void)willMoveToWindow:(UIWindow *)newWindow
 {
-    [_reachability stopNotifier];
+    [super willMoveToWindow:newWindow];
+    
+    if (newWindow) {
+        [self addLayoutGuideObserversIfNeeded];
+    } else {
+        [self removeLayoutGuideObserversIfNeeded];
+    }
+}
 
-    [[UIDevice currentDevice] endGeneratingDeviceOrientationNotifications];
-    [[NSNotificationCenter defaultCenter] removeObserver:self];
-    [_attributionButton removeObserver:self forKeyPath:@"hidden"];
+- (void)addLayoutGuideObserversIfNeeded
+{
+    UIViewController *viewController = self.viewControllerForLayoutGuides;
+    BOOL useLayoutGuides = viewController.view && viewController.automaticallyAdjustsScrollViewInsets;
+    
+    if (useLayoutGuides && viewController.topLayoutGuide && !_isObservingTopLayoutGuide) {
+        [(NSObject *)viewController.topLayoutGuide addObserver:self forKeyPath:@"bounds" options:0 context:(void *)&MGLLayoutGuidesUpdatedContext];
+        _isObservingTopLayoutGuide = YES;
+    }
+    
+    if (useLayoutGuides && viewController.bottomLayoutGuide && !_isObservingBottomLayoutGuide) {
+        [(NSObject *)viewController.bottomLayoutGuide addObserver:self forKeyPath:@"bounds" options:0 context:(void *)&MGLLayoutGuidesUpdatedContext];
+        _isObservingBottomLayoutGuide = YES;
+    }
+}
 
+- (void)removeLayoutGuideObserversIfNeeded
+{
+    UIViewController *viewController = self.viewControllerForLayoutGuides;
+    
     if (_isObservingTopLayoutGuide) {
-        [(NSObject *)self.viewControllerForLayoutGuides.topLayoutGuide removeObserver:self forKeyPath:@"bounds" context:(void *)&MGLLayoutGuidesUpdatedContext];
+        [(NSObject *)viewController.topLayoutGuide removeObserver:self forKeyPath:@"bounds" context:(void *)&MGLLayoutGuidesUpdatedContext];
+        _isObservingTopLayoutGuide = NO;
     }
     
     if (_isObservingBottomLayoutGuide) {
-        [(NSObject *)self.viewControllerForLayoutGuides.bottomLayoutGuide removeObserver:self forKeyPath:@"bounds" context:(void *)&MGLLayoutGuidesUpdatedContext];
+        [(NSObject *)viewController.bottomLayoutGuide removeObserver:self forKeyPath:@"bounds" context:(void *)&MGLLayoutGuidesUpdatedContext];
+        _isObservingBottomLayoutGuide = NO;
     }
+}
+
+- (void)dealloc
+{
+    [_reachability stopNotifier];
+
+    [[UIDevice currentDevice] endGeneratingDeviceOrientationNotifications];
+    [[NSNotificationCenter defaultCenter] removeObserver:self];
+    [_attributionButton removeObserver:self forKeyPath:@"hidden"];
+
+    [self removeLayoutGuideObserversIfNeeded];
 
     // Removing the annotations unregisters any outstanding KVO observers.
     NSArray *annotations = self.annotations;
@@ -787,25 +823,7 @@ public:
     // is set to YES, -[MGLMapView adjustContentInset] takes top and bottom layout
     // guides into account. To get notified about changes to the layout guides,
     // we need to observe their bounds and re-layout accordingly.
-    
-    UIViewController *viewController = self.viewControllerForLayoutGuides;
-    BOOL useLayoutGuides = viewController.view && viewController.automaticallyAdjustsScrollViewInsets;
-    
-    if (useLayoutGuides && viewController.topLayoutGuide && !_isObservingTopLayoutGuide) {
-        [(NSObject *)viewController.topLayoutGuide addObserver:self forKeyPath:@"bounds" options:0 context:(void *)&MGLLayoutGuidesUpdatedContext];
-        _isObservingTopLayoutGuide = YES;
-    } else if (!useLayoutGuides && _isObservingTopLayoutGuide) {
-        [(NSObject *)viewController.topLayoutGuide removeObserver:self forKeyPath:@"bounds" context:(void *)&MGLLayoutGuidesUpdatedContext];
-        _isObservingTopLayoutGuide = NO;
-    }
-    
-    if (useLayoutGuides && viewController.bottomLayoutGuide && !_isObservingBottomLayoutGuide) {
-        [(NSObject *)viewController.bottomLayoutGuide addObserver:self forKeyPath:@"bounds" options:0 context:(void *)&MGLLayoutGuidesUpdatedContext];
-        _isObservingBottomLayoutGuide = YES;
-    } else if (!useLayoutGuides && _isObservingBottomLayoutGuide) {
-        [(NSObject *)viewController.bottomLayoutGuide removeObserver:self forKeyPath:@"bounds" context:(void *)&MGLLayoutGuidesUpdatedContext];
-        _isObservingBottomLayoutGuide = NO;
-    }
+    [self addLayoutGuideObserversIfNeeded];
 }
 
 - (BOOL)isOpaque
@@ -839,8 +857,6 @@ public:
 
     [self adjustContentInset];
     
-    [self observeLayoutGuidesIfNeeded];
-    
     [self layoutOrnaments];
 
     if (!_isTargetingInterfaceBuilder) {
@@ -928,34 +944,6 @@ public:
     self.contentInset = contentInset;
 }
 
-- (void)observeLayoutGuidesIfNeeded
-{
-    UIViewController *viewController = self.viewControllerForLayoutGuides;
-    BOOL useLayoutGuides = viewController.view && viewController.automaticallyAdjustsScrollViewInsets;
-    
-    if (!_isObservingTopLayoutGuide && useLayoutGuides && viewController.topLayoutGuide)
-    {
-        [(NSObject *)viewController.topLayoutGuide addObserver:self forKeyPath:@"bounds" options:0 context:MGLLayoutGuidesUpdatedContext];
-        _isObservingTopLayoutGuide = YES;
-    }
-    else if (!useLayoutGuides && _isObservingTopLayoutGuide)
-    {
-        [(NSObject *)viewController.topLayoutGuide removeObserver:self forKeyPath:@"bounds" context:MGLLayoutGuidesUpdatedContext];
-        _isObservingTopLayoutGuide = NO;
-    }
-    
-    if (!_isObservingBottomLayoutGuide && useLayoutGuides && viewController.bottomLayoutGuide)
-    {
-        [(NSObject *)viewController.bottomLayoutGuide addObserver:self forKeyPath:@"bounds" options:0 context:MGLLayoutGuidesUpdatedContext];
-        _isObservingBottomLayoutGuide = YES;
-    }
-    else if (!useLayoutGuides && _isObservingBottomLayoutGuide)
-    {
-        [(NSObject *)viewController.bottomLayoutGuide removeObserver:self forKeyPath:@"bounds" context:MGLLayoutGuidesUpdatedContext];
-        _isObservingBottomLayoutGuide = NO;
-    }
-}
-
 - (void)setContentInset:(UIEdgeInsets)contentInset
 {
     [self setContentInset:contentInset animated:NO];