OpenLayers 3 API Documentation - Class: ol.layer.Base

Base class for all layers. The most basic implementation is ol.layer.Layer. See ol.layer for all implementations.

Source:

layerbase.js, line 50

Extends

ol.Object

Methods

bindTo Stability: experimental

The bindTo method allows you to set up a two-way binding between a source and target object. The method returns an ol.ObjectAccessor with a transform method that lets you transform values on the way from the source to the target and on the way back.

For example, if you had two map views (sourceView and targetView) and you wanted the target view to have double the resolution of the source view, you could transform the resolution on the way to and from the target with the following:

sourceView.bindTo('resolution', targetView)
  .transform(
    function(sourceResolution) {
      // from sourceView.resolution to targetView.resolution
      return 2 * sourceResolution;
    },
    function(targetResolution) {
      // from targetView.resolution to sourceView.resolution
      return targetResolution / 2;
    }
  );

Parameters:

Name	Type	Argument	Description
`key`	string		Key name.
`target`	ol.Object		Target.
`targetKey`	string	<optional>	Target key.

Inherited From:

ol.Object#bindTo

Source:

object.js, line 247

Returns:

Type: ol.ObjectAccessor

dispatchChangeEvent Stability: experimental

Dispatches a change event. Register a listener for this event to get notified of changes.

Inherited From:

ol.Observable#dispatchChangeEvent

Source:

observable.js, line 39

Fires:

event:change

get Stability: experimental

Gets a value.

Parameters:

Name	Type	Description
`key`	string	Key name.

Inherited From:

ol.Object#get

Source:

object.js, line 304

Returns:

Value.

Type: *

getBrightness Stability: experimental

Source:

layerbase.js, line 84

Returns:

Brightness.

Type: number | undefined

getContrast Stability: experimental

Source:

layerbase.js, line 98

Returns:

Contrast.

Type: number | undefined

getHue Stability: experimental

Source:

layerbase.js, line 112

Returns:

Hue.

Type: number | undefined

getKeys Stability: experimental

Get a list of object property names.

Inherited From:

ol.Object#getKeys

Source:

object.js, line 332

Returns:

List of property names.

Type: Array.<string>

getMaxResolution Stability: experimental

Source:

layerbase.js, line 169

Returns:

MaxResolution.

Type: number | undefined

getMinResolution Stability: experimental

Source:

layerbase.js, line 183

Returns:

MinResolution.

Type: number | undefined

getOpacity Stability: experimental

Source:

layerbase.js, line 197

Returns:

Opacity.

Type: number | undefined

getProperties Stability: experimental

Get an object of all property names and values.

Inherited From:

ol.Object#getProperties

Source:

object.js, line 364

Returns:

Object.

Type: Object.<string, *>

getSaturation Stability: experimental

Source:

layerbase.js, line 211

Returns:

Saturation.

Type: number | undefined

getVisible Stability: experimental

Source:

layerbase.js, line 231

Returns:

Visible.

Type: boolean | undefined

notify Stability: experimental

Notify all observers of a change on this property. This notifies both objects that are bound to the object's property as well as the object that it is bound to.

Parameters:

Name	Type	Description
`key`	string	Key name.

Inherited From:

ol.Object#notify

Source:

object.js, line 384

on Stability: experimental

Listen for a certain type of event.

Parameters:

Name	Type	Argument	Description
`type`	string \| Array.<string>		The event type or array of event types.
`listener`	function		The listener function.
`this`	Object	<optional>	The object to use as `this` in `listener`.

Inherited From:

ol.Observable#on

Source:

observable.js, line 61

Returns:

Unique key for the listener.

Type: goog.events.Key

once Stability: experimental

Listen once for a certain type of event.

Parameters:

Name	Type	Argument	Description
`type`	string \| Array.<string>		The event type or array of event types.
`listener`	function		The listener function.
`this`	Object	<optional>	The object to use as `this` in `listener`.

Inherited From:

ol.Observable#once

Source:

observable.js, line 74

Returns:

Unique key for the listener.

Type: goog.events.Key

set Stability: experimental

Sets a value.

Parameters:

Name	Type	Description
`key`	string	Key name.
`value`	*	Value.

Inherited From:

ol.Object#set

Source:

object.js, line 415

setBrightness Stability: experimental

Adjust the layer brightness. A value of -1 will render the layer completely black. A value of 0 will leave the brightness unchanged. A value of 1 will render the layer completely white. Other values are linear multipliers on the effect (values are clamped between -1 and 1).

The filter effects draft [1] says the brightness function is supposed to render 0 black, 1 unchanged, and all other values as a linear multiplier.

The current WebKit implementation clamps values between -1 (black) and 1 (white) [2]. There is a bug open to change the filter effect spec [3].

TODO: revisit this if the spec is still unmodified before we release

[1] https://dvcs.w3.org/hg/FXTF/raw-file/tip/filters/index.html [2] https://github.com/WebKit/webkit/commit/8f4765e569 [3] https://www.w3.org/Bugs/Public/show_bug.cgi?id=15647

Parameters:

Name	Type	Description
`brightness`	number \| undefined	Brightness.

Source:

layerbase.js, line 262

setContrast Stability: experimental

Adjust the layer contrast. A value of 0 will render the layer completely grey. A value of 1 will leave the contrast unchanged. Other values are linear multipliers on the effect (and values over 1 are permitted).

Parameters:

Name	Type	Description
`contrast`	number \| undefined	Contrast.

Source:

layerbase.js, line 279

setHue Stability: experimental

Apply a hue-rotation to the layer. A value of 0 will leave the hue unchanged. Other values are radians around the color circle.

Parameters:

Name	Type	Description
`hue`	number \| undefined	Hue.

Source:

layerbase.js, line 294

setMaxResolution Stability: experimental

Parameters:

Name	Type	Description
`maxResolution`	number \| undefined	MaxResolution.

Source:

layerbase.js, line 307

setMinResolution Stability: experimental

Parameters:

Name	Type	Description
`minResolution`	number \| undefined	MinResolution.

Source:

layerbase.js, line 320

setOpacity Stability: experimental

Parameters:

Name	Type	Description
`opacity`	number \| undefined	Opacity.

Source:

layerbase.js, line 333

setSaturation Stability: experimental

Adjust layer saturation. A value of 0 will render the layer completely unsaturated. A value of 1 will leave the saturation unchanged. Other values are linear multipliers of the effect (and values over 1 are permitted).

Parameters:

Name	Type	Description
`saturation`	number \| undefined	Saturation.

Source:

layerbase.js, line 351

setValues Stability: experimental

Sets a collection of key-value pairs.

Parameters:

Name	Type	Description
`values`	Object.<string, *>	Values.

Inherited From:

ol.Object#setValues

Source:

object.js, line 444

setVisible Stability: experimental

Parameters:

Name	Type	Description
`visible`	boolean \| undefined	Visible.

Source:

layerbase.js, line 364

un Stability: experimental

Unlisten for a certain type of event.

Parameters:

Name	Type	Argument	Description
`type`	string \| Array.<string>		The event type or array of event types.
`listener`	function		The listener function.
`this`	Object	<optional>	The object to use as `this` in `listener`.