MaplyRemoteTileSource

@interface MaplyRemoteTileSource : NSObject <MaplyTileSource>

The remote tile source knows how to fetch remote image pyramids.

This is the MaplyTileSource compliant object that communicates with remote servers and fetches individual tiles as needed by the MaplyQuadImageTileLayer.

It can be initialized in a couple of different ways depending on the information you have available. Either you explicitly provide the baseURL, min and max levels and such, or hand in an NSDictionary that’s been parsed from a tile spec.

The remote tile source also handles cacheing if it you give it a cacheDir to work in. By default cacheing is off (so be careful).

See

MaplyQuadImageTilesLayer

  • Initialize with enough information to fetch remote tiles.

    This version of the init method takes all the explicit information needed to fetch remote tiles. This includes the base URL, file extension (e.g. image type), and min and max zoom levels.

    Declaration

    Objective-C

    - (nullable instancetype)initWithBaseURL:(NSString *_Nonnull)baseURL
                                     ext:(NSString *_Nullable)ext
                                 minZoom:(int)minZoom
                                 maxZoom:(int)maxZoom;

    Swift

    init?(baseURL: String, ext: String?, minZoom: Int32, maxZoom: Int32)

    Parameters

    baseURL

    The base URL for fetching TMS tiles.
    ext

    Extension for the images we’ll be fetching, typically @png or @jpg
    minZoom

    The minimum zoom level to fetch. This really should be 0.
    maxZoom

    The maximum zoom level to fetch.

    Return Value

    The MaplyRemoteTileSource object or nil on failure.

  • Initialize from a remote tile spec.

    This version of the initializer takes an NSDictionary parsed from a JSON tile spec. Take a look at the tile spec itself here (https://github.com/mapbox/tilejson-spec). Basically it defines the available URLs (there can be multiple), the min and max zoom levels, coordinate system (not really) and file extension. In many cases the coordinate system extents can’t be trusted.

    Declaration

    Objective-C

    - (nullable instancetype)initWithTilespec:(NSDictionary *_Nonnull)jsonSpec;

    Swift

    init?(tilespec jsonSpec: [AnyHashable : Any])

    Parameters

    jsonSpec

    An NSDictionary parsed from the JSON tile spec.

  • Read the image, but only if it’s in the cache.

    MaplyRemoteTileSource uses asynchronous fetching. This method is inherently synchronous. You expect it to return the image for a tile right now. So this method only works if the tile is in the cache. Be sure to check on that first.

    Declaration

    Objective-C

    - (nullable id)imageForTile:(MaplyTileID)tileID;

    Swift

    func image(forTile tileID: MaplyTileID) -> Any?

    Parameters

    tileID

    The tile (that should be in the cache) you want to read.

  • Initialize with remote tile info.

    The MaplyRemoteTileInfo object stores all the specifics about remote tile data. We actually created one of those for the other init calls in this objects. Fill that object in and then call this initializaer.

    Declaration

    Objective-C

    - (nullable instancetype)initWithInfo:
    (NSObject<MaplyRemoteTileInfoProtocol> *_Nonnull)info;

    Swift

    init?(info: NSObjectProtocol

    Parameters

    info

    The MaplyRemoteTileInfo describing where to fetch the tiles.

  • Description of where we fetch the tiles from and where to cache them.

    Declaration

    Objective-C

    @property (readonly, nonatomic, nonnull)
    NSObject<MaplyRemoteTileInfoProtocol> *tileInfo;

    Swift

    var tileInfo: NSObjectProtocol

  • A delegate for tile loads and failures.

    If set, you’ll get callbacks when the various tiles load (or don’t). You get called in all sorts of threads. Act accordingly.

    Declaration

    Objective-C

    @property (readwrite, nonatomic, nullable)
    NSObject<MaplyRemoteTileSourceDelegate> *delegate;

    Swift

    weak var delegate: MaplyRemoteTileSourceDelegate? { get set }

  • Passes through the coord system from the MaplyRemoteTileInfo

    Declaration

    Objective-C

    @property (readwrite, strong, nonatomic, nonnull)
    MaplyCoordinateSystem *coordSys;

    Swift

    var coordSys: MaplyCoordinateSystem { get set }

  • Passes through the cacheDir from the MaplyRemoteTileInfo

    Declaration

    Objective-C

    @property (readwrite, strong, nonatomic, nullable) NSString *cacheDir;

    Swift

    var cacheDir: String? { get set }

  • If set, we’ll track the outstanding connections across all remote tile sources

    Declaration

    Objective-C

    + (void)setTrackConnections:(_Bool)track;

    Swift

    class func setTrackConnections(_ track: Bool)

  • Number of outstanding connections across all remote tile sources

    Declaration

    Objective-C

    + (int)numOutstandingConnections;

    Swift

    class func numOutstandingConnections() -> Int32