MGLComputedShapeSource

@interface MGLComputedShapeSource : MGLSource

MGLComputedShapeSource is a map content source that supplies vector shapes, one tile at a time, to be shown on the map on demand. You implement a class conforming to the MGLComputedShapeSourceDataSource protocol that returns instances of MGLShape or MGLFeature, then add a computed shape source to an MGLStyle object along with an MGLVectorStyleLayer object. The vector style layer defines the appearance of any content supplied by the computed shape source.

MGLComputedShapeSource is similar to MGLShapeSource but is optimized for data sets that change dynamically or are too large to fit completely in memory. It is also useful for data that is divided into tiles in a format other than Vector Tiles. For GeoJSON data, use the MGLShapeSource class. For static tiles or Vector Tiles, use the MGLVectorTileSource class.

You can add and remove sources dynamically using methods such as -[MGLStyle addSource:] and -[MGLStyle sourceWithIdentifier:]. This class cannot be represented in a style JSON file; you must add it ot the style at runtime.

-initWithIdentifier:options:

Returns a custom shape data source initialized with an identifier, and a dictionary of options for the source according to the style specification.

This class supports the following options: MGLShapeSourceOptionMinimumZoomLevel, MGLShapeSourceOptionMaximumZoomLevel, MGLShapeSourceOptionBuffer, MGLShapeSourceOptionSimplificationTolerance, MGLShapeSourceOptionWrapsCoordinates, and MGLShapeSourceOptionClipsCoordinates. Shapes provided by a computed shape source cannot be clustered.

Declaration

Objective-C

- (nonnull instancetype)
initWithIdentifier:(nonnull NSString *)identifier
           options:
               (nullable NSDictionary<MGLShapeSourceOption, id> *)options;

Swift

init(identifier: String, options: [MGLShapeSourceOption : Any]? = nil)

Parameters

identifier

A string that uniquely identifies the source.

options

An NSDictionary of options for this source.

-initWithIdentifier:dataSource:options:

Returns a custom shape data source initialized with an identifier, data source, and a dictionary of options for the source according to the style specification.

This class supports the following options: MGLShapeSourceOptionMinimumZoomLevel, MGLShapeSourceOptionMaximumZoomLevel, MGLShapeSourceOptionBuffer, MGLShapeSourceOptionSimplificationTolerance, MGLShapeSourceOptionWrapsCoordinates, and MGLShapeSourceOptionClipsCoordinates. Shapes provided by a computed shape source cannot be clustered.

Declaration

Objective-C

- (nonnull instancetype)
initWithIdentifier:(nonnull NSString *)identifier
        dataSource:(nonnull id<MGLComputedShapeSourceDataSource>)dataSource
           options:
               (nullable NSDictionary<MGLShapeSourceOption, id> *)options;

Swift

convenience init(identifier: String, dataSource: MGLComputedShapeSourceDataSource, options: [MGLShapeSourceOption : Any]? = nil)

Parameters

identifier

A string that uniquely identifies the source.

options

An NSDictionary of options for this source.

-invalidateBounds:

Invalidates all the features and properties intersecting with or contained in the specified bounds. New fetch requests will immediately be invoked on the MGLComputedShapeSourceDataSource.

Declaration

Objective-C

- (void)invalidateBounds:(MGLCoordinateBounds)bounds;

Swift

func invalidateBounds(_ bounds: MGLCoordinateBounds)

Parameters

bounds

Coordinate bounds to invalidate.

-invalidateTileAtX:y:zoomLevel:

Invalidates all the feautres and properties of a given tile. A new fetch request will immediately be invoked on the MGLComputedShapeSourceDataSource.

Declaration

Objective-C

- (void)invalidateTileAtX:(NSUInteger)x
                    y:(NSUInteger)y
            zoomLevel:(NSUInteger)zoomLevel;

Swift

func invalidateTileAt(x: UInt, y: UInt, zoomLevel: UInt)

Parameters

x

Tile X coordinate.

y

Tile Y coordinate.

zoomLevel

Tile zoom level.

-setFeatures:inTileAtX:y:zoomLevel:

Set a new set of features for a tile. This method can be invkoed from background threads. For best performance, use this method only to update tiles that have already been requested through MGLComputedShapeSourceDataSource.

Declaration

Objective-C

- (void)setFeatures:(nonnull NSArray<MGLShape<MGLFeature> *> *)features
      inTileAtX:(NSUInteger)x
              y:(NSUInteger)y
      zoomLevel:(NSUInteger)zoomLevel;

Parameters

features

Features for the tile.

x

Tile X coordinate.

y

Tile Y coordinate.

zoomLevel

Tile zoom level.

dataSource

An object that implements the MGLComputedShapeSourceDataSource protocol that will be queried for tile data.

Declaration

Objective-C

@property (nonatomic, weak, readwrite, nullable)
id<MGLComputedShapeSourceDataSource>
    dataSource;

Swift

weak var dataSource: MGLComputedShapeSourceDataSource? { get set }

requestQueue

A queue that calls to the data source will be made on.

Declaration

Objective-C

@property (nonatomic, readonly) NSOperationQueue *_Nonnull requestQueue;

Swift

var requestQueue: OperationQueue { get }