[ios] Limit annotation view pan gesture check to own recognizer (#5813)

Allows non-dragging pans that are initiated on views to pan the underlying map.

Annotation views each have long press and pan gesture recognizers. If a
view is not draggable or not in a positive dragging state, the pan
gesture recognizer should not begin. This commit makes the criteria for
rejecting pans more strict — only `_panGestureRecognizer` should be
rejected, not the entire `UIPanGestureRecognizer` class.

Author: friedbunny

platform/ios/CHANGELOG.md

@@ -5,6 +5,7 @@ Mapbox welcomes participation and contributions from everyone.  Please read [CON
 ## 3.3.2
 
 * Fixed a crash that occurred when initializing an MGLMapView on iOS 8.1 or below. ([#5791](https://github.com/mapbox/mapbox-gl-native/pull/5791))
+* Fixed an issue where pan gestures that originated on view annotations would not pan the underlying map. ([#5813](https://github.com/mapbox/mapbox-gl-native/pull/5813))
 
 ## 3.3.1
 

platform/ios/src/MGLAnnotationView.mm

@@ -235,7 +235,7 @@ - (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
 {
     BOOL isDragging = self.dragState == MGLAnnotationViewDragStateDragging;
 
-    if ([gestureRecognizer isKindOfClass:UIPanGestureRecognizer.class] && !(isDragging))
+    if (gestureRecognizer == _panGestureRecognizer && !(isDragging))
     {
         return NO;
     }