Interface: ITileLayer

H .map .layer.ITileLayer

This interface describes a layer which provides data partitioned in quad-tree tiles in an x, y, z fashion (where z describes the level within the tree and x and y describe the absolute column and row indices within the level).

Adding a layer implementing this interface to the layer collection causes the render engine to retrieve tiles and render the data contained within the tiles (see H.map.provider.Tile).

Methods

cancelTile (x, y, z)

This method cancels a previously requested tile.

Name	Type	Description
`x`	number	Tile row position
`y`	number	Tile column position
`z`	number	Zoom level

requestTile (x, y, z, cacheOnly)H.map.provider.Tile | undefined

This method requests a single tile for the specified tile coordinates.

Name	Type	Description
`x`	number	Tile row position
`y`	number	Tile column position
`z`	number	The zoom level for which the tile is requested
`cacheOnly`	boolean	A value indicating whether only cached tiles are to be considered `true`

Returns:

Type	Description
H.map.provider.Tile \| undefined	A tile object matching the supplied coordinates if the tile is already loaded, otherwise the method starts loading the tile and returns `undefined`

requestTiles (boundingBox, zoomLevel, cacheOnly, prioCenter, opt_requesterId)H.map.layer.ITileLayer.Response

This method requests tiles for a specific bounding box and zoom level (z-value).

An implementing object must calculate the tile grid which intersects with the bounding box. An ITileLayer does not need to return all tiles immediately (as loading tile data from remote sources may be asynchronous). The implementing object may return a partial response if the full response cannot be synchronously provided to the renderer.

The response object returned by this method must contain the number of tiles which intersect with the bounding box at the zoom level specified by the caller.

This method is called by the renderer for each rendering cycle. An implementing object must make sure that calling this method does not impede the rendering process, therefore caching of remote objects is strongly advised.

Name	Type	Description
`boundingBox`	H.geo.Rect	The rectangular area for which tiles are to be returned
`zoomLevel`	number	The zoom level for which the tiles are requested
`cacheOnly`	boolean	Indicates whether only cached tiles are to be considered (`true`)
`prioCenter`	H.math.Point	The priority center as an offset in screen pixel relative to the center
`opt_requesterId`	*	optional Unique identifier of the requester, is used when layer is shared between different maps

Returns:

Type	Description
H.map.layer.ITileLayer.Response	A response object containing the total number of tiles requested and the tile objects that could be immediately returned

Type Definitions

H.map.layer.ITileLayer.Options Object

This object defines the configuration options which are used to initialize a TileLayer instance.

Properties:

Name	Type	Argument	Description
`min`	number	<optional>	The minimum zoom level for which the layer is considered for rendering, the default is `0`
`max`	number	<optional>	The maximum zoom level for which the layer is considered for rendering, the default is `22`
`dark`	boolean	<optional>	Indicates whether the content of the given layer is mainly dark, the default is `false` See also `H.Map.Options#autoColor`
`projection`	H.geo.IProjection	<optional>	The projection to be used for the given layer, the default is `H.geo.mercator`

H.map.layer.ITileLayer.Response Object

This is a response object for a tile request. It contains the total number of elements requested and an array of currently available tiles.

Properties:

Name	Type	Description
`total`	number	The total number of requested tiles
`tiles`	Array.<H.map.provider.Tile>	The tiles which the provider can currently return synchronously