[ios, macos] Simplify MGLSource and subclasses (#7377)

* [ios, macos] Audited source headers for nullability

* [macos] Made MGLTileSet public

* [ios, macos] Replaced MGLTileSet with MGLTileSource

MGLRasterSource and MGLVectorSource now share a common abstract superclass, MGLTileSource. MGLTileSet has been removed. MGLTileSource is modeled after mbgl::style::RasterSource and mbgl::style::VectorSource. It has initializers that incorporate the parameters of MGLTileSet’s initializers, but it lacks getters for everything but the attribution string. MGLTileSet’s properties have been converted into options that can be passed into MGLTileSource’s initializers in a dictionary.

Properly implement rawSource as a covariant property so that it doesn’t end up getting autosynthesized as a shadow ivar. This prevents concrete subclasses of MGLSource from setting _rawSource directly but getting a different value out of self.rawSource.

Marked -[MGLSource init] as unavailable and ensured that concrete subclasses of MGLSource have the right set of initializers marked as designated initializers.

Documentation comments for each concrete source class identify the corresponding source type in the style specification. Clarified the purpose of MGLTileSetScheme, now known as MGLTileCoordinateSystem.

* [ios, macos] Clarified tile size interpretation

Sticking to a default value of 256 for mapbox: URLs, but other URLs get the standard 512 value.

* [ios, macos] rawSource is always set

* [ios, macos] Cleaned up MGLShapeSource initialization

rawSource is never nil, so there’s no need for a -commonInit method. Extracted -geoJSONOptions from MGLShapeSource into a standalone function for easier testing.

* [ios, macos] Synchronized headers in project

Realphabetized headers in groups. Added headers missing from one project or the other.

* [ios, macos] Added MGLShape methods to (de)serialize GeoJSON data

Added a class initializer and instance method to MGLShape that deserialize and serialize the shape as GeoJSON data, respectively. The new initializer handles parsing errors gracefully.

Removed methods specific to GeoJSON data from MGLShapeSource, in an effort to reduce parallel state. Developers are now expected to go through the new MGLShape initializer to get an MGLShape representation. Alternatively, a local file URL can be passed into the other MGLShapeSource initializer.

* [ios, macos] Typo in assertion message

* [ios, macos] Simplified GeoJSON serialization

Every MGLShape now knows its most specific mbgl::GeoJSON representation.

* [ios, macos] Reremoved MGLFeaturePrivate

mbgl::GeoJSON, which is a variant, allows a single GeoJSON representation method to traffic in whatever type is needed for a particular shape class. This change removes some hidden private protocols, which are a bug waiting to happen.

* [ios, macos] Fixed covariant rawLayer property

Properly implement rawLayer as a covariant property so that it doesn’t end up getting autosynthesized as a shadow ivar. This prevents concrete subclasses of MGLStyleLayer from setting _rawLayer directly but getting a different value out of self.rawLayer.

* [ios, macos] Use MGLAttributionInfo for source attribution

Made MGLAttributionInfo public. Replaced MGLTileSource’s attribution property with an attributionInfos property set to an array of MGLAttributionInfo objects. Added an MGLTileSourceOption for specifying an array of MGLAttributionInfo objects instead of an HTML string (either is acceptable when creating an MGLTileSource).

* [ios, macos] Corrected method references in documentation

1 files changed, 35 insertions, 0 deletions

diff --git a/platform/darwin/src/MGLShape.h b/platform/darwin/src/MGLShape.h
index ce9375c910..e7dbe90242 100644
--- a/platform/darwin/src/MGLShape.h
+++ b/platform/darwin/src/MGLShape.h
@@ -13,6 +13,30 @@ NS_ASSUME_NONNULL_BEGIN
  */
 @interface MGLShape : NSObject <MGLAnnotation>
 
+#pragma mark Creating a Shape
+
+/**
+ Returns an `MGLShape` object initialized with the given data interpreted as a
+ string containing a GeoJSON object.
+ 
+ If the GeoJSON object is a geometry, the returned value is a kind of
+ `MGLShape`. If it is a feature object, the returned value is a kind of
+ `MGLShape` that conforms to the `MGLFeature` protocol. If it is a feature
+ collection object, the returned value is an instance of
+ `MGLShapeCollectionFeature`.
+ 
+ @param data String data containing GeoJSON source code.
+ @param encoding The encoding used by `data`.
+ @param outError Upon return, if an error has occurred, a pointer to an
+    `NSError` object describing the error. Pass in `NULL` to ignore any error.
+ @return An `MGLShape` object representation of `data`, or `nil` if `data` could
+    not be parsed as valid GeoJSON source code. If `nil`, `outError` contains an
+    `NSError` object describing the problem.
+ */
++ (nullable instancetype)shapeWithData:(NSData *)data encoding:(NSStringEncoding)encoding error:(NSError * _Nullable *)outError;
+
+#pragma mark Accessing the Shape Attributes
+
 /**
  The title of the shape annotation. The default value of this property is `nil`.
  */
@@ -34,6 +58,17 @@ NS_ASSUME_NONNULL_BEGIN
 
 #endif
 
+#pragma mark Creating GeoJSON Data
+
+/**
+ Returns the GeoJSON string representation of the shape encapsulated in a data
+ object.
+ 
+ @param encoding The string encoding to use.
+ @return A data object containing the shape’s GeoJSON string representation.
+ */
+- (NSData *)geoJSONDataUsingEncoding:(NSStringEncoding)encoding;
+
 @end
 
 NS_ASSUME_NONNULL_END