@protocol MGLOverlay <MGLAnnotation>

The MGLOverlay protocol defines a specific type of annotation that represents both a point and an area on a map. Overlay objects are essentially data objects that contain the geographic data needed to represent the map area. For example, overlays can take the form of common shapes such as rectangles and circles. They can also describe polygons and other complex shapes.

You use overlays to layer more sophisticated content on top of a map view. For example, you could use an overlay to show the boundaries of a national park or trace a bus route along city streets. The Mapbox iOS SDK defines several concrete classes that conform to this protocol and define standard shapes.

Because overlays are also annotations, they have similar usage pattern to annotations. When added to a map view using the -addOverlay: method, that view detects whenever the overlay’s defined region intersects the visible portion of the map. At that point, the map view asks its delegate to provide a special overlay view to draw the visual representation of the overlay. If you add an overlay to a map view as an annotation instead, it is treated as an annotation with a single point.

  • The approximate center point of the overlay area. (required) (read-only)

    This point is typically set to the center point of the map’s bounding rectangle. It is used as the anchor point for any callouts displayed for the annotation.



    @property (readonly, nonatomic) CLLocationCoordinate2D coordinate;
  • The cooordinate rectangle that encompasses the overlay. (required) (read-only)

    This property contains the smallest rectangle that completely encompasses the overlay. Implementers of this protocol must set this area when implementing their overlay class, and after setting it, you must not change it.



    @property (readonly, nonatomic) MGLCoordinateBounds overlayBounds;
  • Returns a Boolean indicating whether the specified rectangle intersects the receiver’s shape.

    You can implement this method to provide more specific bounds checking for an overlay. If you do not implement it, the bounding rectangle is used to detect intersections.



    - (BOOL)intersectsOverlayBounds:(MGLCoordinateBounds)overlayBounds;



    The rectangle to intersect with the receiver’s area.

    Return Value

    YES if any part of the map rectangle intersects the receiver’s shape or NO if it does not.