Class: Layer

H .map .layer.Layer

new H.map.layer.Layer (opt_options)

The Layer class represents an object that is evaluated by the renderer in the order in which it is added to the collection of map layers. It provides the basic infrastructure for dispatching update events to the renderer when new data is available.

A layer is defined by a minimum and maximum zoom level for which it can provide data to the renderer and a projection it uses to transform geographic coordinates into 2D projected world coordinates.

Name	Type	Description
`opt_options`	H.map.layer.Layer.Options	optional An optional configuration object

Extends

H.util.EventTarget

Members

max number

This property holds a value of the maximum zoom level at which the given layer can be rendered.

min number

This property holds the value of the minimum zoom level at which the given layer can be rendered.

pixelProjection H.geo.PixelProjection non-null

This property indicates the projection type for the given layer.

Methods

addEventListener (type, handler, opt_capture, opt_scope) inherited

This method adds a listener for a specific event.

Note that to prevent potential memory leaks, you must either call removeEventListener or dispose on the given object when you no longer need it.

Name	Type	Description
`type`	string	The name of the event
`handler`	function	An event handler function
`opt_capture`	boolean	optional `true` indicates that the method should listen in the capture phase (bubble otherwise)
`opt_scope`	Object	optional An object defining the scope for the handler function

addOnDisposeCallback (callback, opt_scope) inherited

This method adds a callback which is triggered when the EventTarget object is being disposed.

Name	Type	Description
`callback`	function	The callback function.
`opt_scope`	Object	optional An optional scope for the callback function

dispatchEvent (evt) inherited

This method dispatches an event on the EventTarget object.

Name	Type	Description
`evt`	H.util.Event \| string	An object representing the event or a string with the event name

dispose () inherited

This method removes listeners from the given object. Classes that extend EventTarget may need to override this method in order to remove references to DOM Elements and additional listeners.

getCopyrights (boundingBox, level)Array.<!H.map.ICopyright>

This method retrieves the copyright of the current data provider.

Note: This function must be overridden by any class derived from Layer. The default implementation returns null.

Name	Type	Description
`boundingBox`	H.geo.Rect	The bounding box for which to retrieve the copyright information
`level`	number	The zoom level for which to retrieve the copyright information

Returns:

Type	Description
Array.<!H.map.ICopyright>	A list of copyright information objects for the provided area and zoom level

getProvider ()H.map.provider.Provider

This method returns the provider which feeds this layer with data.

Returns:

Type	Description
H.map.provider.Provider	this layer's provider

isValid (zoomLevel)boolean

This method checks if a zoom level can be served by the given layer.

Name	Type	Description
`zoomLevel`	number	The zoom level to check

Returns:

Type	Description
boolean	`true` if the given layer can provide data for the zoom level, otherwise `false`

removeEventListener (type, handler, opt_capture, opt_scope) inherited

This method removes a previously added listener from the EventTarget instance.

Name	Type	Description
`type`	string	The name of the event
`handler`	function	A previously added event handler
`opt_capture`	boolean	optional `true` indicates that the method should listen in the capture phase (bubble otherwise)
`opt_scope`	Object	optional An object defining the scope for the handler function

setMax (max)H.map.layer.Layer

This method sets the maximum zoom level at which the given layer provides content.

Name	Type	Description
`max`	number	The new maximum zoom level for the given layer

Throws:

if the max parameter is not a number or if it is smaller that the current minimum zoom level

Returns:

Type	Description
H.map.layer.Layer	An object representing the given layer

setMin (min)H.map.layer.Layer

This method sets the minimum zoom level at which the given layer provides content.

Name	Type	Description
`min`	number	The new minimum zoom level for the given layer

Throws:

if the min parameter is not a number or if it is larger that the current maximum zoom level

Returns:

Type	Description
H.map.layer.Layer	An object representing the given layer

Type Definitions

H.map.layer.Layer.Options Object

This object encapsulates options which can be used when creating new layer object.

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`
`minWorldSize`	number	<optional>	The minimal world size at zoom level `0`, the default is `256`
`provider`	H.map.provider.Provider	<optional>	The provider that provides data for the given layer.

Events

update

Event fired when the data associated with the given layer is updated.

Type:

H.util.Event