Class: Layer

Subclasses

• ol.layer.Image
• ol.layer.Tile
• ol.layer.Vector

Extends

• ol.layer.Base

Observable Properties

Name	Type	Settable	ol.ObjectEvent type	Description
brightness	number	yes	change:brightness	The brightness of the layer.
contrast	number	yes	change:contrast	The contrast of the layer.
extent	ol.Extent | undefined	yes	change:extent	The layer extent.
hue	number	yes	change:hue	The hue of the layer.
maxResolution	number	yes	change:maxresolution	The maximum resolution of the layer.
minResolution	number	yes	change:minresolution	The minimum resolution of the layer.
opacity	number	yes	change:opacity	The opacity of the layer.
saturation	number	yes	change:saturation	The saturation of the layer.
source	ol.source.Source	yes	change:source	The layer source (or null if not yet set).
visible	boolean	yes	change:visible	The visibility of the layer.

Methods

bindTo(key, target, opt_targetKey){ol.ObjectAccessor} inherited experimental

src/ol/object.js, line 326

The bindTo method allows you to set up a two-way binding between a source and target object. The method returns an object with a transform method that you can use to provide from and to functions to 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;
    }
  );

Name	Type	Description
key	string	Key name.
target	ol.Object	Target.
targetKey	string	Target key.

changed() inherited experimental

src/ol/observable.js, line 52

Increases the revision counter and disptches a 'change' event.

Fires:

• change experimental

get(key){*} inherited experimental

src/ol/object.js, line 354

Gets a value.

Name	Type	Description
key	string	Key name.

Returns:

Value.

getBrightness(){number} inherited experimental

src/ol/layer/layerbase.js, line 94

Returns:

The brightness of the layer.

getContrast(){number} inherited experimental

src/ol/layer/layerbase.js, line 108

Returns:

The contrast of the layer.

getExtent(){ol.Extent|undefined} inherited

src/ol/layer/layerbase.js, line 182

Returns:

The layer extent.

getHue(){number} inherited experimental

src/ol/layer/layerbase.js, line 122

Returns:

The hue of the layer.

getKeys(){Array.<string>} inherited experimental

src/ol/object.js, line 373

Get a list of object property names.

Returns:

List of property names.

getMaxResolution(){number} inherited

src/ol/layer/layerbase.js, line 197

Returns:

The maximum resolution of the layer.

getMinResolution(){number} inherited

src/ol/layer/layerbase.js, line 212

Returns:

The minimum resolution of the layer.

getOpacity(){number} inherited

src/ol/layer/layerbase.js, line 227

Returns:

The opacity of the layer.

getProperties(){Object.<string, *>} inherited experimental

src/ol/object.js, line 405

Get an object of all property names and values.

Returns:

Object.

getRevision(){number} inherited experimental

src/ol/observable.js, line 62

Returns:

Revision.

getSaturation(){number} inherited experimental

src/ol/layer/layerbase.js, line 241

Returns:

The saturation of the layer.

getSource(){ol.source.Source}

src/ol/layer/layer.js, line 91

Get the layer source.

Returns:

The layer source (or null if not yet set).

getVisible(){boolean} inherited

src/ol/layer/layerbase.js, line 261

Returns:

The visibility of the layer.

on(type, listener, opt_this){goog.events.Key} inherited

src/ol/observable.js, line 75

Listen for a certain type of event.

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

Returns:

Unique key for the listener.

once(type, listener, opt_this){goog.events.Key} inherited

src/ol/observable.js, line 88

Listen once for a certain type of event.

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

Returns:

Unique key for the listener.

set(key, value) inherited experimental

src/ol/object.js, line 437

Sets a value.

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

setBrightness(brightness) inherited experimental

src/ol/layer/layerbase.js, line 292

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

Name	Type	Description
brightness	number	The brightness of the layer.

setContrast(contrast) inherited experimental

src/ol/layer/layerbase.js, line 310

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).

Name	Type	Description
contrast	number	The contrast of the layer.

setExtent(extent) inherited

src/ol/layer/layerbase.js, line 342

Set the extent at which the layer is visible. If undefined, the layer will be visible at all extents.

Name	Type	Description
extent	ol.Extent | undefined	The extent of the layer.

setHue(hue) inherited experimental

src/ol/layer/layerbase.js, line 326

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

Name	Type	Description
hue	number	The hue of the layer.

setMaxResolution(maxResolution) inherited

src/ol/layer/layerbase.js, line 356

Name	Type	Description
maxResolution	number	The maximum resolution of the layer.

setMinResolution(minResolution) inherited

src/ol/layer/layerbase.js, line 370

Name	Type	Description
minResolution	number	The minimum resolution of the layer.

setOpacity(opacity) inherited

src/ol/layer/layerbase.js, line 384

Name	Type	Description
opacity	number	The opacity of the layer.

setProperties(values) inherited experimental

src/ol/object.js, line 456

Sets a collection of key-value pairs.

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

setSaturation(saturation) inherited experimental

src/ol/layer/layerbase.js, line 403

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).

Name	Type	Description
saturation	number	The saturation of the layer.

setSource(source)

src/ol/layer/layer.js, line 142

Set the layer source.

Name	Type	Description
source	ol.source.Source	The layer source.

setVisible(visible) inherited

src/ol/layer/layerbase.js, line 417

Name	Type	Description
visible	boolean	The visibility of the layer.

un(type, listener, opt_this) inherited

src/ol/observable.js, line 101

Unlisten for a certain type of event.

Name	Type	Description
type	string | Array.<string>	The event type or array of event types.
listener	function	The listener function.
this	Object	The object which was used as this by the listener.

unbind(key) inherited experimental

src/ol/object.js, line 470

Removes a binding. Unbinding will set the unbound property to the current value. The object will not be notified, as the value has not changed.

Name	Type	Description
key	string	Key name.

unbindAll() inherited experimental

src/ol/object.js, line 487

Removes all bindings.

unByKey(key) inherited

src/ol/observable.js, line 114

Removes an event listener using the key returned by on() or once(). Note that using the ol.Observable.unByKey static function is to be preferred.

Name	Type	Description
key	goog.events.Key	The key returned by on() or once().