[ios, osx] Avoid observing coordinate on MGLMultiPoint

There’s no point observing the coordinate key path on MGLMultiPoint, since that property is immutable. Use the observation context instead of performing an annotation tag lookup when a coordinate has changed.

3 files changed, 23 insertions, 32 deletions

diff --git a/platform/ios/CHANGELOG.md b/platform/ios/CHANGELOG.md
index 81a91395aa..faee9409cd 100644
--- a/platform/ios/CHANGELOG.md
+++ b/platform/ios/CHANGELOG.md
@@ -8,7 +8,7 @@ Mapbox welcomes participation and contributions from everyone.  If you’d like
 - Removed the `armv7s` slice from the SDK to reduce its size. iPhone 5 and iPhone 5c automatically use the `armv7` slice instead. ([#4641](https://github.com/mapbox/mapbox-gl-native/pull/4641))
 - The user dot now moves smoothly between user location updates while user location tracking is disabled. ([#1582](https://github.com/mapbox/mapbox-gl-native/pull/1582))
 - User location heading updates now resume properly when an app becomes active again. ([#4674](https://github.com/mapbox/mapbox-gl-native/pull/4674))
-- An MGLAnnotation can be relocated by changing its `coordinate` property in a KVO-compliant way. ([#3835](https://github.com/mapbox/mapbox-gl-native/pull/3835))
+- An MGLAnnotation can be relocated by changing its `coordinate` property in a KVO-compliant way. An MGLMultiPoint cannot be relocated. ([#3835](https://github.com/mapbox/mapbox-gl-native/pull/3835))
 - Setting the `image` property of an MGLAnnotationImage to `nil` resets it to the default red pin image and reclaims resources that can be used to customize additional annotations. ([#3835](https://github.com/mapbox/mapbox-gl-native/pull/3835))
 - Fixed an issue preventing KVO change notifications from being generated on MGLMapView’s `userTrackingMode` key path when `-setUserTrackingMode:animated:` is called. ([#4724](https://github.com/mapbox/mapbox-gl-native/pull/4724))
 - Fixed a hang that could occur if the host application attempts to set user defaults on a background queue. ([#4745](https://github.com/mapbox/mapbox-gl-native/pull/4745))
diff --git a/platform/ios/src/MGLMapView.mm b/platform/ios/src/MGLMapView.mm
index 507a0846d9..1b07c68cf3 100644
--- a/platform/ios/src/MGLMapView.mm
+++ b/platform/ios/src/MGLMapView.mm
@@ -1597,7 +1597,7 @@ mbgl::Duration MGLDurationInSeconds(NSTimeInterval duration)
 
 #pragma mark - Properties -
 
-- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(__unused void *)context
+- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
 {
     if ([keyPath isEqualToString:@"hidden"] && object == _attributionButton)
     {
@@ -1608,19 +1608,16 @@ mbgl::Duration MGLDurationInSeconds(NSTimeInterval duration)
             [MGLMapboxEvents ensureMetricsOptoutExists];
         }
     }
-    else if ([keyPath isEqualToString:@"coordinate"] && [object conformsToProtocol:@protocol(MGLAnnotation)])
+    else if ([keyPath isEqualToString:@"coordinate"] && [object conformsToProtocol:@protocol(MGLAnnotation)] && ![object isKindOfClass:[MGLMultiPoint class]])
     {
         id <MGLAnnotation> annotation = object;
-        MGLAnnotationTag annotationTag = [self annotationTagForAnnotation:annotation];
-        if (annotationTag != MGLAnnotationTagNotFound)
+        MGLAnnotationTag annotationTag = (MGLAnnotationTag)(NSUInteger)context;
+        const mbgl::LatLng latLng = MGLLatLngFromLocationCoordinate2D(annotation.coordinate);
+        MGLAnnotationImage *annotationImage = [self imageOfAnnotationWithTag:annotationTag];
+        _mbglMap->updatePointAnnotation(annotationTag, { latLng, annotationImage.styleIconIdentifier.UTF8String ?: "" });
+        if (annotationTag == _selectedAnnotationTag)
         {
-            const mbgl::LatLng latLng = MGLLatLngFromLocationCoordinate2D(annotation.coordinate);
-            MGLAnnotationImage *annotationImage = [self imageOfAnnotationWithTag:annotationTag];
-            _mbglMap->updatePointAnnotation(annotationTag, { latLng, annotationImage.styleIconIdentifier.UTF8String ?: "" });
-            if (annotationTag == _selectedAnnotationTag)
-            {
-                [self deselectAnnotation:annotation animated:YES];
-            }
+            [self deselectAnnotation:annotation animated:YES];
         }
     }
 }
@@ -2452,6 +2449,7 @@ mbgl::Duration MGLDurationInSeconds(NSTimeInterval duration)
             _annotationContextsByAnnotationTag[annotationTag] = context;
             
             if ([annotation isKindOfClass:[NSObject class]]) {
+                NSAssert(![annotation isKindOfClass:[MGLMultiPoint class]], @"Point annotation should not be MGLMultiPoint.");
                 [(NSObject *)annotation addObserver:self forKeyPath:@"coordinate" options:0 context:(void *)(NSUInteger)annotationTag];
             }
         }
@@ -2469,10 +2467,6 @@ mbgl::Duration MGLDurationInSeconds(NSTimeInterval duration)
             MGLAnnotationContext context;
             context.annotation = annotation;
             _annotationContextsByAnnotationTag[annotationTag] = context;
-            
-            if ([annotation isKindOfClass:[NSObject class]]) {
-                [(NSObject *)annotation addObserver:self forKeyPath:@"coordinate" options:0 context:(void *)(NSUInteger)annotationTag];
-            }
         }
     }
     
@@ -2600,7 +2594,7 @@ mbgl::Duration MGLDurationInSeconds(NSTimeInterval duration)
         
         _annotationContextsByAnnotationTag.erase(annotationTag);
         
-        if ([annotation isKindOfClass:[NSObject class]])
+        if ([annotation isKindOfClass:[NSObject class]] && ![annotation isKindOfClass:[MGLMultiPoint class]])
         {
             [(NSObject *)annotation removeObserver:self forKeyPath:@"coordinate" context:(void *)(NSUInteger)annotationTag];
         }
diff --git a/platform/osx/src/MGLMapView.mm b/platform/osx/src/MGLMapView.mm
index 8be4772c3a..69bc5c87b1 100644
--- a/platform/osx/src/MGLMapView.mm
+++ b/platform/osx/src/MGLMapView.mm
@@ -460,21 +460,20 @@ public:
     }
 }
 
-- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(__unused id)object change:(__unused NSDictionary *)change context:(__unused void *)context {
+- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(__unused NSDictionary *)change context:(void *)context {
     if ([keyPath isEqualToString:@"contentLayoutRect"] ||
         [keyPath isEqualToString:@"titlebarAppearsTransparent"]) {
         [self adjustContentInsets];
     } else if ([keyPath isEqualToString:@"coordinate"] &&
-               [object conformsToProtocol:@protocol(MGLAnnotation)]) {
+               [object conformsToProtocol:@protocol(MGLAnnotation)] &&
+               ![object isKindOfClass:[MGLMultiPoint class]]) {
         id <MGLAnnotation> annotation = object;
-        MGLAnnotationTag annotationTag = [self annotationTagForAnnotation:annotation];
-        if (annotationTag != MGLAnnotationTagNotFound) {
-            const mbgl::LatLng latLng = MGLLatLngFromLocationCoordinate2D(annotation.coordinate);
-            MGLAnnotationImage *annotationImage = [self imageOfAnnotationWithTag:annotationTag];
-            _mbglMap->updatePointAnnotation(annotationTag, { latLng, annotationImage.styleIconIdentifier.UTF8String ?: "" });
-            if (annotationTag == _selectedAnnotationTag) {
-                [self deselectAnnotation:annotation];
-            }
+        MGLAnnotationTag annotationTag = (MGLAnnotationTag)(NSUInteger)context;
+        const mbgl::LatLng latLng = MGLLatLngFromLocationCoordinate2D(annotation.coordinate);
+        MGLAnnotationImage *annotationImage = [self imageOfAnnotationWithTag:annotationTag];
+        _mbglMap->updatePointAnnotation(annotationTag, { latLng, annotationImage.styleIconIdentifier.UTF8String ?: "" });
+        if (annotationTag == _selectedAnnotationTag) {
+            [self deselectAnnotation:annotation];
         }
     }
 }
@@ -1608,6 +1607,7 @@ public:
             _annotationContextsByAnnotationTag[annotationTag] = context;
             
             if ([annotation isKindOfClass:[NSObject class]]) {
+                NSAssert(![annotation isKindOfClass:[MGLMultiPoint class]], @"Point annotation should not be MGLMultiPoint.");
                 [(NSObject *)annotation addObserver:self forKeyPath:@"coordinate" options:0 context:(void *)(NSUInteger)annotationTag];
             }
         }
@@ -1624,10 +1624,6 @@ public:
             MGLAnnotationContext context;
             context.annotation = annotation;
             _annotationContextsByAnnotationTag[annotationTag] = context;
-            
-            if ([annotation isKindOfClass:[NSObject class]]) {
-                [(NSObject *)annotation addObserver:self forKeyPath:@"coordinate" options:0 context:(void *)(NSUInteger)annotationTag];
-            }
         }
     }
     
@@ -1720,7 +1716,8 @@ public:
         
         _annotationContextsByAnnotationTag.erase(annotationTag);
         
-        if ([annotation isKindOfClass:[NSObject class]]) {
+        if ([annotation isKindOfClass:[NSObject class]] &&
+            ![annotation isKindOfClass:[MGLMultiPoint class]]) {
             [(NSObject *)annotation removeObserver:self forKeyPath:@"coordinate" context:(void *)(NSUInteger)annotationTag];
         }
     }