[ios, macos] Add -mapView:didFinishLoadingStyle: delegate method

platform/ios/CHANGELOG.md

@@ -25,6 +25,7 @@ Mapbox welcomes participation and contributions from everyone. Please read [CONT
 * The `circle-pitch-scale` property is now supported in stylesheets, allowing circle features in a tilted base map to scale or remain the same size as the viewing distance changes. ([#5576](https://github.com/mapbox/mapbox-gl-native/pull/5576))
 * The `identifier` property of an MGLFeature may now be either a number or string. ([#5514](https://github.com/mapbox/mapbox-gl-native/pull/5514))
 * If MGLMapView is unable to obtain or parse a style, it now calls its delegate’s `-mapViewDidFailLoadingMap:withError:` method. ([#6145](https://github.com/mapbox/mapbox-gl-native/pull/6145))
+* Added the `-[MGLMapViewDelegate mapView:didFinishLoadingStyle:]` delegate method, which offers the earliest opportunity to modify the layout or appearance of the current style before the map view is displayed to the user. ([#6636](https://github.com/mapbox/mapbox-gl-native/pull/6636))
 * Fixed crashes that could occur when loading a malformed stylesheet. ([#5736](https://github.com/mapbox/mapbox-gl-native/pull/5736))
 * Fixed an issue causing stepwise zoom functions to be misinterpreted. ([#6328](https://github.com/mapbox/mapbox-gl-native/pull/6328))
 * A source’s tiles are no longer rendered when the map is outside the source’s supported zoom levels. ([#6345](https://github.com/mapbox/mapbox-gl-native/pull/6345))

platform/ios/src/MGLMapView.mm

@@ -4566,6 +4566,14 @@ public:
             }
             break;
         }
+        case mbgl::MapChangeDidFinishLoadingStyle:
+        {
+            if ([self.delegate respondsToSelector:@selector(mapView:didFinishLoadingStyle:)])
+            {
+                [self.delegate mapView:self didFinishLoadingStyle:self.style];
+            }
+            break;
+        }
     }
 }
 

platform/ios/src/MGLMapViewDelegate.h

@@ -126,6 +126,23 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)mapViewDidFinishRenderingFrame:(MGLMapView *)mapView fullyRendered:(BOOL)fullyRendered;
 
+/**
+ Tells the delegate that the map has just finished loading a style.
+ 
+ This method is called during the initialization of the map view and after any
+ subsequent loading of a new style. This method is called between the
+ `-mapViewWillStartRenderingMap:` and `-mapViewDidFinishRenderingMap:` delegate
+ methods. Changes to sources or layers of the current style do not cause this
+ method to be called.
+ 
+ This method is the earliest opportunity to modify the layout or appearance of
+ the current style before the map view is displayed to the user.
+
+ @param mapView The map view that has just loaded a style.
+ @param style The style that was loaded.
+ */
+- (void)mapView:(MGLMapView *)mapView didFinishLoadingStyle:(MGLStyle *)style;
+
 #pragma mark Tracking User Location
 
 /**

platform/macos/CHANGELOG.md

@@ -20,6 +20,7 @@
 * Fixed an issue causing an MGLOfflinePack’s progress to continue to update after calling `-suspend`. ([#6186](https://github.com/mapbox/mapbox-gl-native/pull/6186))
 * Fixed an issue preventing cached annotation images from displaying while the device is offline. ([#6358](https://github.com/mapbox/mapbox-gl-native/pull/6358))
 * If MGLMapView is unable to obtain or parse a style, it now calls its delegate’s `-mapViewDidFailLoadingMap:withError:` method. ([#6145](https://github.com/mapbox/mapbox-gl-native/pull/6145))
+* Added the `-[MGLMapViewDelegate mapView:didFinishLoadingStyle:]` delegate method, which offers the earliest opportunity to modify the layout or appearance of the current style before the map view is displayed to the user. ([#6636](https://github.com/mapbox/mapbox-gl-native/pull/6636))
 * Fixed an issue causing stepwise zoom functions to be misinterpreted. ([#6328](https://github.com/mapbox/mapbox-gl-native/pull/6328))
 * A source’s tiles are no longer rendered when the map is outside the source’s supported zoom levels. ([#6345](https://github.com/mapbox/mapbox-gl-native/pull/6345))
 * Fixed a crash that could occur when the device is disconnected while downloading an offline pack. ([#6293](https://github.com/mapbox/mapbox-gl-native/pull/6293))

platform/macos/src/MGLMapView.mm

@@ -873,6 +873,14 @@ public:
             }
             break;
         }
+        case mbgl::MapChangeDidFinishLoadingStyle:
+        {
+            if ([self.delegate respondsToSelector:@selector(mapView:didFinishLoadingStyle:)])
+            {
+                [self.delegate mapView:self didFinishLoadingStyle:self.style];
+            }
+            break;
+        }
     }
 }
 

platform/macos/src/MGLMapViewDelegate.h

@@ -125,6 +125,23 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (void)mapViewDidFinishRenderingFrame:(MGLMapView *)mapView fullyRendered:(BOOL)fullyRendered;
 
+/**
+ Tells the delegate that the map has just finished loading a style.
+
+ This method is called during the initialization of the map view and after any
+ subsequent loading of a new style. This method is called between the
+ `-mapViewWillStartRenderingMap:` and `-mapViewDidFinishRenderingMap:` delegate
+ methods. Changes to sources or layers of the current style do not cause this
+ method to be called.
+
+ This method is the earliest opportunity to modify the layout or appearance of
+ the current style before the map view is displayed to the user.
+
+ @param mapView The map view that has just loaded a style.
+ @param style The style that was loaded.
+ */
+- (void)mapView:(MGLMapView *)mapView didFinishLoadingStyle:(MGLStyle *)style;
+
 #pragma mark Managing the Appearance of Annotations
 
 /**