Class TileCache

  • All Implemented Interfaces:
    Loadable

    public final class TileCache
    extends java.lang.Object
    implements Loadable
    A local cache of pre-rendered map tiles that can be used to create a layer.

    A tile cache stores a collection of images at various scales. A client can request the tiles needed to display a particular map extent. You can use ExportTileCacheTask to generate and download tiles from a service, creating a tile package (.tpk/.tpkx). Alternatively, you can use ArcGIS Pro to create a map tile package and provision it to the device.

    Functional characteristics

    ArcGIS tiled layers do not support reprojection, query, select, identify, or editing.

    Performance characteristics

    Tiles are generated when the cache is created. Requests for tiles are made on multiple threads and handled asynchronously. The size of each returned tile increases as the resolution or complexity of the image in the tile increases. For example, high-resolution imagery tiles can be larger files than topographic mapping for the same area and map extent.

    Local tile caches are ideal for providing basemaps or less frequently changing contextual layers, where network access is limited or non-existent. They can be created and downloaded onto a device by using an ExportTileCacheJob, or alternatively can be provisioned directly to local storage. The supported types of cache are:

    • Tile package (.tpk, .tpkx) - a tile cache of data, packaged into one convenient, portable file, ideal for offline sharing of complete tiled layers in a disconnected environment or via a portal.
    • Compact Cache - a directory structure where groups of tiles are combined into larger .bundle files, preserving performance and reducing copy times and the size on disk of the cache.
    • Exploded Cache - a directory structure where map tiles are stored as individual files.
    A TileCache is often used as a basemap, as shown in the example below. Alternatively, it may be used to create an ArcGISTiledLayer that is added as an operational layer.

    Example for working with a tile cache

     // create a basemap from a local tile package
     TileCache tileCache = new TileCache("MyTiledPackage.tpk");
     ArcGISTiledLayer tiledLayer = new ArcGISTiledLayer(tileCache);
     Basemap basemap = new Basemap(tiledLayer);
    
     ArcGISMap map = new ArcGISMap(basemap);
     // set the map to be displayed in the Map View
     mapView.setMap(map);
     
    Since:
    100.0.0
    See Also:
    ArcGISTiledLayer, Basemap, ExportTileCacheJob.getResult()
    • Constructor Detail

      • TileCache

        public TileCache​(java.lang.String path)
        Creates a tile cache from the given local path to a tile package (.tpk or .tpkx file), or directory containing a compact cache or exploded cache.
        Parameters:
        path - absolute path to the location of the tile cache
        Since:
        100.0.0
    • Method Detail

      • getPath

        public java.lang.String getPath()
        Gets the file path of the tile cache. For caches based on tile packages (.tpk or .tpkx files) this is the full path of the .tpk or .tpkx file; for caches based on compact or exploded caches, this is the path of the directory containing the cache.
        Returns:
        path to the tile cache
        Since:
        100.0.0
      • getTileInfo

        public TileInfo getTileInfo()
        Gets information about the the tiling scheme used by this tile cache, for example, the origin of the cached tiles, the levels of detail available, and the size of each tile.
        Returns:
        information about the tiling scheme of this tile cache
        Since:
        100.0.0
      • getFullExtent

        public Envelope getFullExtent()
        Returns the full extent covered by all tiles in this tile cache.
        Returns:
        the full extent of this tile cache
        Since:
        100.0.0
      • isAntialiasing

        public boolean isAntialiasing()
        Returns if the tile cache has antialiasing or not.
        Returns:
        true if the tile cache has antialiasing, false otherwise
        Since:
        100.1.0
      • getCacheStorageFormat

        public TileCache.StorageFormat getCacheStorageFormat()
        Gets the storage format of this tile cache.
        Returns:
        the storage format of this tile cache
        Since:
        100.10.0
      • getThumbnail

        public byte[] getThumbnail()
        Returns a byte array containing the thumbnail data. Will return null if no thumbnail is available.
        Returns:
        the thumbnail bytes
        Since:
        100.1.0
      • getLoadStatus

        public LoadStatus getLoadStatus()
        Description copied from interface: Loadable
        Returns the LoadStatus of the loadable resource.
        Specified by:
        getLoadStatus in interface Loadable
        Returns:
        the LoadStatus of the loadable resource
      • cancelLoad

        public void cancelLoad()
        Description copied from interface: Loadable
        Cancels loading metadata for the object.

        Cancels loading the metadata if the object is loading, and always invokes the done loading listener.

        A load operation that is in progress (LoadStatus.LOADING state) can be cancelled by calling this method and the resource will transition from LoadStatus.LOADING to LoadStatus.FAILED_TO_LOAD state. If the load operation was successfully cancelled, a CancellationException will be returned from Loadable.getLoadError().

        Cancellation should be used carefully because all enqueued done loading listeners for that resource instance will get invoked with an error stating that the operation was cancelled. Thus, one component in the application can cancel the load operation initiated by other components.

        This method does nothing if the resource is not in LoadStatus.LOADING state.

        Specified by:
        cancelLoad in interface Loadable
      • loadAsync

        public void loadAsync()
        Description copied from interface: Loadable
        Loads the metadata of the loadable resource asynchronously.

        The load status changes from LoadStatus.NOT_LOADED to LoadStatus.LOADING. A listener can be added via Loadable.addDoneLoadingListener(java.lang.Runnable) that is invoked upon completion of the asynchronous load operation.

        If the load operation completes successfully, the load status will be LoadStatus.LOADED, which means the resource has loaded its metadata.

        If the load operation failed, the load status will be LoadStatus.FAILED_TO_LOAD and the error can be retrieved by calling Loadable.getLoadError().

        This method can be called concurrently and repeatedly, but only one attempt is ever made to perform the load operation. If a load operation is already in progress (LoadStatus.LOADING state) when loadAsync is called, it simply piggy-backs on the outstanding operation and the done loading listener added to the loadable resource is enqueued to be invoked when that operation completes. If the operation has already completed (LoadStatus.LOADED or LoadStatus.FAILED_TO_LOAD state) when loadAsync is called, the done loading listener is immediately invoked when added to the loadable resource.

        If a loadable resource has failed to load, calling loadAsync on it subsequently will not change its state. The done loading listener will be invoked immediately when added to the loadable resource. In order to retry loading the resource, Loadable.retryLoadAsync() needs to be used.

        A load operation that is in progress (LoadStatus.LOADING state) can be cancelled by calling Loadable.cancelLoad().

        Specified by:
        loadAsync in interface Loadable
      • retryLoadAsync

        public void retryLoadAsync()
        Description copied from interface: Loadable
        Loads or retries loading metadata for the object asynchronously.

        Will retry loading the metadata if the object's load status is LoadStatus.FAILED_TO_LOAD. Will load the object if it is not loaded. Will not retry to load the object if the object is loaded.

        For more details on the load process see Loadable.loadAsync().

        Specified by:
        retryLoadAsync in interface Loadable
      • addDoneLoadingListener

        public void addDoneLoadingListener​(java.lang.Runnable listener)
        Description copied from interface: Loadable
        Adds a listener to the loadable resource that is invoked when loading has completed.

        The listener may be added at any point, whether the loadable resource has already completed loading or not.

        • For resources that are not loaded when the listener is added (LoadStatus is NOT_LOADED or LOADING): When the resource completes loading, the listener will be invoked on the UI thread if it is added from the UI thread, otherwise it is not guaranteed on which thread the listener is invoked.
        • For resources that are already loaded when the listener is added (LoadStatus is LOADED or FAILED_TO_LOAD): The listener will be called immediately, on the current thread.

        Alternatively, to be notified when there is any change in the load status, use the Loadable.addLoadStatusChangedListener(LoadStatusChangedListener) method instead.

        Specified by:
        addDoneLoadingListener in interface Loadable
        Parameters:
        listener - a Runnable that is invoked upon completion of the load operation
      • removeDoneLoadingListener

        public boolean removeDoneLoadingListener​(java.lang.Runnable listener)
        Description copied from interface: Loadable
        Removes a done loading listener from the loadable resource.
        Specified by:
        removeDoneLoadingListener in interface Loadable
        Parameters:
        listener - the listener to be removed
        Returns:
        true if the listener was removed, otherwise false
      • addLoadStatusChangedListener

        public void addLoadStatusChangedListener​(LoadStatusChangedListener listener)
        Description copied from interface: Loadable
        Adds a LoadStatusChangedListener to the loadable resource that is invoked whenever the load status changes.

        Adding this listener on the UI thread will cause it to be invoked on the UI thread, otherwise it is not guaranteed on which thread the listener is invoked.

        The listener will not be called if added to a loadable resource that has already completed loading. To be notified when a loadable resource has completed loading, including if the resource is already loaded when the listener is added, use the Loadable.addDoneLoadingListener(Runnable) method.

        Specified by:
        addLoadStatusChangedListener in interface Loadable
        Parameters:
        listener - the LoadStatusChangedListener to be added
      • removeLoadStatusChangedListener

        public boolean removeLoadStatusChangedListener​(LoadStatusChangedListener listener)
        Description copied from interface: Loadable
        Removes a LoadStatusChangedListener from the loadable resource.
        Specified by:
        removeLoadStatusChangedListener in interface Loadable
        Parameters:
        listener - the LoadStatusChangedListener to be removed
        Returns:
        true if the listener was removed, otherwise false