fixes #6467: document style layer classes

platform/darwin/src/MGLBackgroundStyleLayer.h

@@ -6,6 +6,12 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+/**
+ A map style's background layer is the bottommost layer and is used to style a color 
+ or pattern to show below all other map features. You can query an `MGLMapView` for its 
+ `style` and obtain the background layer using the `-[MGLStyle layerWithIdentifier:]` 
+ method and passing `background` for the identifier. 
+ */
 @interface MGLBackgroundStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier;

platform/darwin/src/MGLCircleStyleLayer.h

@@ -16,9 +16,14 @@ typedef NS_ENUM(NSUInteger, MGLCircleStyleLayerCirclePitchScale) {
     MGLCircleStyleLayerCirclePitchScaleViewport,
 };
 
+/**
+ A circle layer which allows customization of styling properties at runtime. You may 
+ instantiate a new circle layer to add to a map style or you may query an 
+ `MGLMapView` for its `style` and obtain existing layers using the 
+ `-[MGLStyle layerWithIdentifier:]` method. 
+ */
 @interface MGLCircleStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
-
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
 
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer;

platform/darwin/src/MGLFillStyleLayer.h

@@ -11,9 +11,14 @@ typedef NS_ENUM(NSUInteger, MGLFillStyleLayerFillTranslateAnchor) {
     MGLFillStyleLayerFillTranslateAnchorViewport,
 };
 
+/**
+ A fill layer which allows customization of styling properties at runtime. You may 
+ instantiate a new fill layer to add to a map style or you may query an 
+ `MGLMapView` for its `style` and obtain existing layers using the 
+ `-[MGLStyle layerWithIdentifier:]` method. 
+ */
 @interface MGLFillStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
-
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
 
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer;

platform/darwin/src/MGLLineStyleLayer.h

@@ -23,9 +23,14 @@ typedef NS_ENUM(NSUInteger, MGLLineStyleLayerLineTranslateAnchor) {
     MGLLineStyleLayerLineTranslateAnchorViewport,
 };
 
+/**
+ A line layer which allows customization of styling properties at runtime. You may 
+ instantiate a new line layer to add to a map style or you may query an 
+ `MGLMapView` for its `style` and obtain existing layers using the 
+ `-[MGLStyle layerWithIdentifier:]` method. 
+ */
 @interface MGLLineStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
-
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
 
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer;

platform/darwin/src/MGLRasterStyleLayer.h

@@ -6,9 +6,14 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+/**
+ A raster layer which allows customization of styling properties at runtime. You may 
+ instantiate a new raster layer to add to a map style or you may query an 
+ `MGLMapView` for its `style` and obtain existing layers using the 
+ `-[MGLStyle layerWithIdentifier:]` method. 
+ */
 @interface MGLRasterStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
-
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
 
 

platform/darwin/src/MGLStyleLayer.h.ejs

@@ -33,9 +33,24 @@ typedef NS_ENUM(NSUInteger, MGL<%- camelize(type) %>StyleLayer<%- camelize(prope
 
 <% } -%>
 <% } -%>
+<% if (type == 'background') { -%>
+/**
+ A map style's background layer is the bottommost layer and is used to style a color 
+ or pattern to show below all other map features. You can query an `MGLMapView` for its 
+ `style` and obtain the background layer using the `-[MGLStyle layerWithIdentifier:]` 
+ method and passing `background` for the identifier. 
+ */
+<% } else { -%>
+/**
+ A <%- type %> layer which allows customization of styling properties at runtime. You may 
+ instantiate a new <%- type %> layer to add to a map style or you may query an 
+ `MGLMapView` for its `style` and obtain existing layers using the 
+ `-[MGLStyle layerWithIdentifier:]` method. 
+ */
+<% } -%>
 @interface MGL<%- camelize(type) %>StyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
-
 <% if (type == 'background') { -%>
+
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier;
 <% } -%>
 

platform/darwin/src/MGLSymbolStyleLayer.h

@@ -70,9 +70,14 @@ typedef NS_ENUM(NSUInteger, MGLSymbolStyleLayerTextTranslateAnchor) {
     MGLSymbolStyleLayerTextTranslateAnchorViewport,
 };
 
+/**
+ A symbol layer which allows customization of styling properties at runtime. You may 
+ instantiate a new symbol layer to add to a map style or you may query an 
+ `MGLMapView` for its `style` and obtain existing layers using the 
+ `-[MGLStyle layerWithIdentifier:]` method. 
+ */
 @interface MGLSymbolStyleLayer : MGLBaseStyleLayer <MGLStyleLayer>
 
-
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source;
 
 - (instancetype)initWithLayerIdentifier:(NSString *)layerIdentifier source:(MGLSource *)source sourceLayer:(NSString *)sourceLayer;