[ios, macos] Use NSDictionary for geojson source options.

This removes a previous implementation of geojson options that used
a new type to transfer the data around. Added in its place is
an options API that takes an NSDictionary that works similarly to
NSAttributedString and many other Cocoa APIs that take options.

The options parser now expects the developer to send values of the
type noted in the documentation and it simply converts the NSNumber
to the correct type (integer, double, or bool) for mbgl. However, an
exception is raised if the value is not an NSNumber.

platform/darwin/src/MGLGeoJSONSource.h

@@ -1,12 +1,55 @@
 #import "MGLSource.h"
 
 #import "MGLTypes.h"
-#import "MGLGeoJSONOptions.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
 @protocol MGLFeature;
 
+/**
+ An `NSNumber` object containing a Boolean enabling or disabling clustering.
+ If the `features` property contains point features, setting this option to
+ `YES` clusters the points by radius into groups. The default value is `NO`.
+ */
+extern NSString * const MGLGeoJSONClusterOption;
+
+/**
+ An `NSNumber` object containing an integer; specifies the radius of each
+ cluster when clustering points, measured in <sup>1</sup>/<sub>512</sub>ths of a
+ tile. The default value is 50.
+ */
+extern NSString * const MGLGeoJSONClusterRadiusOption;
+
+/**
+ An `NSNumber` object containing an integer; specifies the maximum zoom level at
+ which to cluster points. Defaults to one zoom level less than the value of
+ `MGLGeoJSONMaximumZoomLevelOption`, so that at the last zoom level, the
+ features are not clustered.
+ */
+extern NSString * const MGLGeoJSONClusterMaximumZoomLevelOption;
+
+/**
+ An `NSNumber` object containing an integer; specifies the maximum zoom level at
+ which to create vector tiles. A greater value produces greater detail at high
+ zoom levels. The default value is 18.
+ */
+extern NSString * const MGLGeoJSONMaximumZoomLevelOption;
+
+/**
+ An `NSNumber` object containing an integer; specifies the tile buffer size on
+ each side. This option is measured in <sup>1</sup>/<sub>512</sub>ths of a tile.
+ A higher value reduces rendering artifacts near tile edges but may impact
+ performance. The default value is 128.
+ */
+extern NSString * const MGLGeoJSONBufferOption;
+
+/**
+ An `NSNumber` object containing a double; specifies the Douglas-Peucker
+ simplification tolerance. A greater value produces simpler geometries and
+ improves performance. The default value is 0.375.
+ */
+extern NSString * const MGLGeoJSONToleranceOption;
+
 @interface MGLGeoJSONSource : MGLSource
 
 /**
@@ -39,8 +82,6 @@ NS_ASSUME_NONNULL_BEGIN
  */
 @property (nonatomic, readonly, nullable) NSURL *URL;
 
-@property (nonatomic, readonly, nullable) MGLGeoJSONOptions *geoJSONOptions;
-
 /**
  Initializes a source with the given identifier and GeoJSON data.
  
@@ -49,7 +90,14 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier geoJSONData:(NSData *)data NS_DESIGNATED_INITIALIZER;
 
-- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier geoJSONData:(NSData *)data options:(MGLGeoJSONOptions *)options NS_DESIGNATED_INITIALIZER;
+/**
+ Initializes a source with the given identifier, GeoJSON data, and a dictionary of options for the source.
+ 
+ @param sourceIdentifier A string that uniquely identifies the source.
+ @param geoJSONData An NSData object representing GeoJSON source code.
+ @param options An NSDictionary of attributes for this source specified by the <a href="https://www.mapbox.com/mapbox-gl-style-spec/#sources-geojson">the style specification</a>.
+ */
+- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier geoJSONData:(NSData *)data options:(NS_DICTIONARY_OF(NSString *, id) *)options NS_DESIGNATED_INITIALIZER;
 
 /**
  Initializes a source with the given identifier and URL.
@@ -60,6 +108,16 @@ NS_ASSUME_NONNULL_BEGIN
  */
 - (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier URL:(NSURL *)url NS_DESIGNATED_INITIALIZER;
 
+/**
+ Initializes a source with the given identifier, a URL, and a dictionary of options for the source.
+ 
+ @param sourceIdentifier A string that uniquely identifies the source.
+ @param URL An HTTP(S) URL, absolute file URL, or local file URL relative to the
+    current application’s resource bundle.
+ @param options An NSDictionary of attributes for this source specified by the <a href="https://www.mapbox.com/mapbox-gl-style-spec/#sources-geojson">the style specification</a>.
+ */
+- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier URL:(NSURL *)url options:(NS_DICTIONARY_OF(NSString *, id) *)options NS_DESIGNATED_INITIALIZER;
+
 @end
 
 NS_ASSUME_NONNULL_END

platform/darwin/src/MGLGeoJSONSource.mm

@@ -7,48 +7,113 @@
 
 #include <mbgl/style/sources/geojson_source.hpp>
 
+NSString * const MGLGeoJSONClusterOption = @"MGLGeoJSONCluster";
+NSString * const MGLGeoJSONClusterRadiusOption = @"MGLGeoJSONClusterRadius";
+NSString * const MGLGeoJSONClusterMaximumZoomLevelOption = @"MGLGeoJSONClusterMaximumZoomLevel";
+NSString * const MGLGeoJSONMaximumZoomLevelOption = @"MGLGeoJSONMaximumZoomLevel";
+NSString * const MGLGeoJSONBufferOption = @"MGLGeoJSONBuffer";
+NSString * const MGLGeoJSONToleranceOption = @"MGLGeoJSONOptionsClusterTolerance";
+
+@interface MGLGeoJSONSource ()
+
+@property (nonatomic, readwrite) NSDictionary *options;
+
+@end
+
 @implementation MGLGeoJSONSource
 
-- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier geoJSONData:(NSData *)data {
-    if (self = [super initWithSourceIdentifier:sourceIdentifier]) {
+- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier geoJSONData:(NSData *)data
+{
+    if (self = [super initWithSourceIdentifier:sourceIdentifier])
+    {
         _geoJSONData = data;
     }
     return self;
 }
 
-- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier geoJSONData:(NSData *)data options:(MGLGeoJSONOptions *)options
+- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier geoJSONData:(NSData *)data options:(NS_DICTIONARY_OF(NSString *, id) *)options
 {
-    if (self = [super initWithSourceIdentifier:sourceIdentifier]) {
+    if (self = [super initWithSourceIdentifier:sourceIdentifier])
+    {
         _geoJSONData = data;
-        _geoJSONOptions = options;
+        _options = options;
     }
     return self;
 }
 
-- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier URL:(NSURL *)url {
-    if (self = [super initWithSourceIdentifier:sourceIdentifier]) {
+- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier URL:(NSURL *)url
+{
+    if (self = [super initWithSourceIdentifier:sourceIdentifier])
+    {
         _URL = url;
     }
     return self;
 }
 
-- (mbgl::style::GeoJSONOptions)mbgl_geoJSONOptions
+- (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier URL:(NSURL *)url options:(NS_DICTIONARY_OF(NSString *, id) *)options
+{
+    if (self = [super initWithSourceIdentifier:sourceIdentifier])
+    {
+        _URL = url;
+        _options = options;
+    }
+    return self;
+}
+
+- (mbgl::style::GeoJSONOptions)geoJSONOptions
+{
+    auto mbglOptions = mbgl::style::GeoJSONOptions();
+
+    if (self.options[MGLGeoJSONMaximumZoomLevelOption]) {
+        id value = self.options[MGLGeoJSONMaximumZoomLevelOption];
+        [self validateValue:value];
+        mbglOptions.maxzoom = [value integerValue];
+    }
+
+    if (self.options[MGLGeoJSONBufferOption]) {
+        id value = self.options[MGLGeoJSONBufferOption];
+        [self validateValue:value];
+        mbglOptions.buffer = [value integerValue];
+    }
+
+    if (self.options[MGLGeoJSONToleranceOption]) {
+        id value = self.options[MGLGeoJSONToleranceOption];
+        [self validateValue:value];
+        mbglOptions.tolerance = [value doubleValue];
+    }
+
+    if (self.options[MGLGeoJSONClusterRadiusOption]) {
+        id value = self.options[MGLGeoJSONClusterRadiusOption];
+        [self validateValue:value];
+        mbglOptions.clusterRadius = [value integerValue];
+    }
+
+    if (self.options[MGLGeoJSONClusterMaximumZoomLevelOption]) {
+        id value = self.options[MGLGeoJSONClusterMaximumZoomLevelOption];
+        [self validateValue:value];
+        mbglOptions.clusterMaxZoom = [value integerValue];
+    }
+
+    if (self.options[MGLGeoJSONClusterOption]) {
+        id value = self.options[MGLGeoJSONClusterOption];
+        [self validateValue:value];
+        mbglOptions.cluster = [value boolValue];
+    }
+
+    return mbglOptions;
+}
+
+- (void)validateValue:(id)value
 {
-    auto options = mbgl::style::GeoJSONOptions();
-    options.maxzoom = self.geoJSONOptions.maximumZoom;
-    options.buffer = self.geoJSONOptions.buffer;
-    options.tolerance = self.geoJSONOptions.tolerance;
-    options.cluster = self.geoJSONOptions.cluster;
-    options.clusterRadius = self.geoJSONOptions.clusterRadius;
-    options.clusterMaxZoom = self.geoJSONOptions.clusterMaximumZoom;
-    return options;
+    if (! [value isKindOfClass:[NSNumber class]])
+    {
+        [NSException raise:@"Value not handled" format:@"%@ is not an NSNumber", value];
+    }
 }
 
-- (std::unique_ptr<mbgl::style::Source>)mbgl_source
+- (std::unique_ptr<mbgl::style::Source>)mbglSource
 {
-    auto source = self.geoJSONOptions
-    ? std::make_unique<mbgl::style::GeoJSONSource>(self.sourceIdentifier.UTF8String, [self mbgl_geoJSONOptions])
-    : std::make_unique<mbgl::style::GeoJSONSource>(self.sourceIdentifier.UTF8String);
+    auto source = std::make_unique<mbgl::style::GeoJSONSource>(self.sourceIdentifier.UTF8String, [self geoJSONOptions]);
 
     if (self.URL) {
         NSURL *url = self.URL.mgl_URLByStandardizingScheme;

platform/darwin/src/MGLGeoJSONSource_Private.h

@@ -0,0 +1,9 @@
+#import "MGLGeoJSONSource_Private.h"
+
+#include <mbgl/style/sources/geojson_source.hpp>
+
+@interface MGLGeoJSONSource (Private)
+
+- (mbgl::style::GeoJSONOptions)geoJSONOptions;
+
+@end

platform/darwin/src/MGLRasterSource.mm

@@ -14,7 +14,7 @@ - (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier URL:(NSURL
     return self;
 }
 
-- (std::unique_ptr<mbgl::style::Source>)mbgl_source {
+- (std::unique_ptr<mbgl::style::Source>)mbglSource {
     auto source = std::make_unique<mbgl::style::RasterSource>(self.sourceIdentifier.UTF8String,
                                                               self.URL.absoluteString.UTF8String,
                                                               uint16_t(self.tileSize));

platform/darwin/src/MGLSource.mm

@@ -11,7 +11,7 @@ - (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier {
     return self;
 }
 
-- (std::unique_ptr<mbgl::style::Source>)mbgl_source {
+- (std::unique_ptr<mbgl::style::Source>)mbglSource {
     [NSException raise:@"Subclasses must override this method" format:@""];
     return nil;
 }

platform/darwin/src/MGLSource_Private.h

@@ -5,7 +5,7 @@
 
 @interface MGLSource (Private)
 
-- (std::unique_ptr<mbgl::style::Source>)mbgl_source;
+- (std::unique_ptr<mbgl::style::Source>)mbglSource;
 
 @property (nonatomic) mbgl::style::Source *source;
 

platform/darwin/src/MGLStyle.mm

@@ -181,7 +181,7 @@ - (void)insertLayer:(id <MGLStyleLayer, MGLStyleLayer_Private>)styleLayer
 
 - (void)addSource:(MGLSource *)source
 {
-    self.mapView.mbglMap->addSource([source mbgl_source]);
+    self.mapView.mbglMap->addSource([source mbglSource]);
 }
 
 - (void)removeSource:(MGLSource *)source

platform/darwin/src/MGLVectorSource.mm

@@ -15,7 +15,7 @@ - (instancetype)initWithSourceIdentifier:(NSString *)sourceIdentifier URL:(NSURL
     return self;
 }
 
-- (std::unique_ptr<mbgl::style::Source>)mbgl_source
+- (std::unique_ptr<mbgl::style::Source>)mbglSource
 {
     auto source = std::make_unique<mbgl::style::VectorSource>(self.sourceIdentifier.UTF8String, self.URL.absoluteString.UTF8String);
     return std::move(source);