#1225 - Initial setup of MapboxGL as a singleton object with access token

gyp/platform-ios.gypi

@@ -17,6 +17,7 @@
         '../platform/darwin/image.mm',
         '../platform/darwin/reachability.m',
         '../include/mbgl/ios/MapboxGL.h',
+        '../platform/ios/MapboxGL.m',
         '../include/mbgl/ios/MGLMapboxEvents.h',
         '../platform/ios/MGLMapboxEvents.m',
         '../include/mbgl/ios/MGLMapView.h',

include/mbgl/ios/MapboxGL.h

@@ -2,3 +2,9 @@
 #import "MGLMapView.h"
 #import "MGLTypes.h"
 #import "MGLUserLocation.h"
+
+@interface MapboxGL : NSObject
+
++ (void) sharedInstanceWithAccessToken:(NSString *)token;
+
+@end

platform/ios/MapboxGL.m

@@ -0,0 +1,39 @@
+#import <Foundation/Foundation.h>
+
+#import "MapboxGL.h"
+
+@interface MapboxGL()
+
+@end
+
+@property (atomic) NSString *accessToken;
+
+@implementation MapboxGL
+
+
+// Can be called from any thread. Called implicitly from any
+// public class convenience methods.
+//
++ (instancetype) sharedInstanceWithAccessToken:(NSString *)token {
+    static dispatch_once_t onceToken;
+    static MapboxGL *_sharedManager;
+    dispatch_once(&onceToken, ^{
+        if ( ! NSProcessInfo.processInfo.mgl_isInterfaceBuilderDesignablesAgent) {
+            void (^setupBlock)() = ^{
+                _sharedManager = [[self alloc] init];
+                _sharedManager.accessToken = token;
+            };
+            if ( ! [[NSThread currentThread] isMainThread]) {
+                dispatch_sync(dispatch_get_main_queue(), ^{
+                    setupBlock();
+                });
+            }
+            else {
+                setupBlock();
+            }
+        }
+    });
+    return _sharedManager;
+}
+
+@end