Made MGLMapView designable in IB

When an access token is set in the Attributes inspector (or as a user-defined runtime attribute), we draw some lovely Mapbox branding so the view shows up. (Manipulating invisible rectangles is a frustrating exercise, I’m told.) In the absence of an access token, the view displays a helpful message with directions for obtaining and setting the access token.

Along the way, completely opt out of `MGLMapboxEvents` when targeting Interface Builder, because touching Core Location throws an exception in that environment and it doesn’t make sense to record any metrics when designing on the Interface Builder canvas. Also, don’t start `mbgl::Map` at all (and don’t update it) because none of the runtime drawing code should ever be run in the designable. Normally these chunks of code would be excluded in IB using the TARGET_INTERFACE_BUILDER preprocessor macro. However, Mapbox GL is being packaged as a static library, so the macro is only evaluated when the library is prebuilt, even if the library eventually makes its way into the CocoaPods-generated framework. Instead, we detect that we’re being run by the IBDesignablesAgentCocoaTouch process.

Overrode `-[MGLMapView initWithFrame:]` to call `-commonInit`. We’ve marked this initializer unavailable in the header, but IB still calls it regardless.

Fixes #929.

1 files changed, 6 insertions, 5 deletions

diff --git a/include/mbgl/ios/MGLMapView.h b/include/mbgl/ios/MGLMapView.h
index dcf1313a8c..4139ef51cc 100644
--- a/include/mbgl/ios/MGLMapView.h
+++ b/include/mbgl/ios/MGLMapView.h
@@ -13,20 +13,21 @@
 *   Use of MGLMapView requires a Mapbox API access token. Obtain an access token on the [Mapbox account page](https://www.mapbox.com/account/apps/). If you instantiate an MGLMapView from Interface Builder, rendering of the map won't begin until the accessToken property has been set.
 *
 *   @warning Please note that you are responsible for getting permission to use the map data, and for ensuring your use adheres to the relevant terms of use. */
+IB_DESIGNABLE
 @interface MGLMapView : UIView
 
 #pragma mark - Initializing a Map View
 
 /** @name Initializing a Map View */
 
-/** Initialize a map view with a given frame, style URL, and access token.
+/** Initialize a map view with a given frame, access token, and style URL.
 *   @param frame The frame with which to initialize the map view.
 *   @param accessToken A Mapbox API access token.
 *   @param styleURL The map style URL to use. Can be either an HTTP/HTTPS URL or a Mapbox map ID style URL (`mapbox://<user.style>`).
 *   @return An initialized map view, or `nil` if the map view was unable to be initialized. */
 - (instancetype)initWithFrame:(CGRect)frame accessToken:(NSString *)accessToken styleURL:(NSURL *)styleURL;
 
-/** Initialize a map view with a given frame, the default style, and an access token.
+/** Initialize a map view with the default style given a frame and access token.
 *   @param frame The frame with which to initialize the map view.
 *   @param accessToken A Mapbox API access token.
 *   @return An initialized map view, or `nil` if the map view was unable to be initialized. */
@@ -49,7 +50,7 @@
 /** A view controller whose top and bottom layout guides to use for proper setup of constraints in the map view internals.
 *
 *   Certain components of the map view, such as the heading compass and the data attribution button, need to be aware of the view controller layout in order to avoid positioning content under a top navigation bar or a bottom toolbar. */
-@property (nonatomic, weak) UIViewController *viewControllerForLayoutGuides;
+@property (nonatomic, weak) IBOutlet UIViewController *viewControllerForLayoutGuides;
 
 #pragma mark - Accessing Map Properties
 
@@ -81,7 +82,7 @@
 /** @name Accessing the Delegate */
 
 // TODO
-@property(nonatomic, weak) id<MGLMapViewDelegate> delegate;
+@property(nonatomic, weak) IBOutlet id<MGLMapViewDelegate> delegate;
 
 #pragma mark - Manipulating the Visible Portion of the Map
 
@@ -134,7 +135,7 @@
 - (void)setDirection:(CLLocationDirection)direction animated:(BOOL)animated;
 
 /** Resets the map rotation to a northern heading. */
-- (void)resetNorth;
+- (IBAction)resetNorth;
 
 #pragma mark - Converting Map Coordinates