[ios] Add annotation view initializer with annotation and reuse id (#9029)

platform/ios/CHANGELOG.md

@@ -17,6 +17,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 
 ### Annotations
 
+* Added a new initializer to `MGLAnnotationView` so that it is possible to create a new instance with an associated annotation object. ([#9029](https://github.com/mapbox/mapbox-gl-native/pull/9029))
 * Fixed an issue causing a view-backed annotation to disappear immediately instead of animating when the annotation’s `coordinate` property is set to a value outside the current viewport. ([#8565](https://github.com/mapbox/mapbox-gl-native/pull/8565))
 * Fixed an issue in which `MGLMapView` overrode the tint colors of its annotation views. ([#8789](https://github.com/mapbox/mapbox-gl-native/pull/8789))
 

platform/ios/src/MGLAnnotationView.h

@@ -73,6 +73,36 @@ typedef NS_ENUM(NSUInteger, MGLAnnotationViewDragState) {
  */
 - (instancetype)initWithReuseIdentifier:(nullable NSString *)reuseIdentifier;
 
+/**
+ Initializes and returns a new annotation view object.
+ 
+ Providing an annotation allows you to explicitly associate the annotation instance
+ with the new view and, in custom subclasses of `MGLAnnotationView`, customize the view
+ based on properties of the annotation instance in an overridden initializer. However,
+ annotation views that are reused will not necessarily be associated with the
+ same annotation they were initialized with. Also, annotation views that are in
+ the reuse queue will have a nil value for the annotation property. Passing an annotation
+ instance to the view is optional and the map view will automatically associate annotations
+ with views when views are provided to the map via the `-[MGLMapViewDelegate mapView:viewForAnnotation:]`
+ method.
+ 
+ The reuse identifier provides a way for you to improve performance by recycling
+ annotation views as they enter and leave the map’s viewport. As an annotation
+ leaves the viewport, the map view moves its associated view to a reuse queue.
+ When a new annotation becomes visible, you can request a view for that
+ annotation by passing the appropriate reuse identifier string to the
+ `-[MGLMapView dequeueReusableAnnotationViewWithIdentifier:]` method.
+ 
+ @param annotation The annotation object to associate with the new view.
+ @param reuseIdentifier A unique string identifier for this view that allows you
+ to reuse this view with multiple similar annotations. You can set this
+ parameter to `nil` if you don’t intend to reuse the view, but it is a good
+ idea in general to specify a reuse identifier to avoid creating redundant
+ views.
+ @return The initialized annotation view object.
+ */
+- (instancetype)initWithAnnotation:(nullable id<MGLAnnotation>)annotation reuseIdentifier:(nullable NSString *)reuseIdentifier;
+
 /**
  Called when the view is removed from the reuse queue.
 

platform/ios/src/MGLAnnotationView.mm

@@ -19,12 +19,20 @@
 
 @implementation MGLAnnotationView
 
-- (instancetype)initWithReuseIdentifier:(NSString *)reuseIdentifier
-{
-    self = [self initWithFrame:CGRectZero];
++ (BOOL)supportsSecureCoding {
+    return YES;
+}
+
+- (instancetype)initWithReuseIdentifier:(NSString *)reuseIdentifier {
+    return [self initWithAnnotation:nil reuseIdentifier:reuseIdentifier];
+}
+
+- (instancetype)initWithAnnotation:(nullable id<MGLAnnotation>)annotation reuseIdentifier:(nullable NSString *)reuseIdentifier {
+    self = [super initWithFrame:CGRectZero];
     if (self)
     {
         _lastAppliedScaleTransform = CATransform3DIdentity;
+        _annotation = annotation;
         _reuseIdentifier = [reuseIdentifier copy];
         _scalesWithViewingDistance = YES;
         _enabled = YES;
@@ -32,10 +40,6 @@
     return self;
 }
 
-+ (BOOL)supportsSecureCoding {
-    return YES;
-}
-
 - (instancetype)initWithCoder:(NSCoder *)decoder {
     if (self = [super initWithCoder:decoder]) {
         _reuseIdentifier = [decoder decodeObjectOfClass:[NSString class] forKey:@"reuseIdentifier"];

platform/ios/test/MGLAnnotationViewTests.m

@@ -85,7 +85,7 @@ static NSString * const MGLTestAnnotationReuseIdentifer = @"MGLTestAnnotationReu
 
     if (!annotationView)
     {
-        annotationView = [[MGLAnnotationView alloc] initWithReuseIdentifier:MGLTestAnnotationReuseIdentifer];
+        annotationView = [[MGLAnnotationView alloc] initWithAnnotation:annotation reuseIdentifier:MGLTestAnnotationReuseIdentifer];
     }
 
     _annotationView = annotationView;