Class: Base

ol.layer.Base

Abstract base class; normally only used for creating subclasses and not instantiated in apps. Note that with ol.layer.Base and all its subclasses, any property set in the options is set as a ol.Object property on the layer object, so is observable, and has get/set accessors.

new ol.layer.Base(options)

src/ol/layer/base.js, line 37
Name Type Description
options

Layer options.

Name Type Description
opacity number | undefined

Opacity (0, 1). Default is 1.

visible boolean | undefined

Visibility. Default is true.

extent ol.Extent | undefined

The bounding extent for layer rendering. The layer will not be rendered outside of this extent.

zIndex number | undefined experimental

The z-index for layer rendering. At rendering time, the layers will be ordered, first by Z-index and then by position. The default Z-index is 0.

minResolution number | undefined

The minimum resolution (inclusive) at which this layer will be visible.

maxResolution number | undefined

The maximum resolution (exclusive) below which this layer will be visible.

Fires:

Subclasses

Extends

Observable Properties

Name Type Settable ol.ObjectEvent type Description
extent ol.Extent | undefined yes change:extent

The layer extent.

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.

visible boolean yes change:visible

The visibility of the layer.

zIndex number yes change:zindex

The Z-index of the layer.

Methods

changed() inherited experimental

src/ol/observable.js, line 58

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

dispatchEvent(event) inherited experimental

src/ol/observable.js, line 75

Dispatches an event and calls all listeners listening for events of this type. The event parameter can either be a string or an Object with a type property.

Name Type Description
event Object | ol.events.Event | string

Event object.

get(key){*} inherited

src/ol/object.js, line 148

Gets a value.

Name Type Description
key string

Key name.

Returns:
Value.

getExtent(){ol.Extent|undefined}

src/ol/layer/base.js, line 112

Return the extent of the layer or undefined if it will be visible regardless of extent.

Returns:
The layer extent.

getKeys(){Array.<string>} inherited

src/ol/object.js, line 162

Get a list of object property names.

Returns:
List of property names.

getMaxResolution(){number}

src/ol/layer/base.js, line 124

Return the maximum resolution of the layer.

Returns:
The maximum resolution of the layer.

getMinResolution(){number}

src/ol/layer/base.js, line 136

Return the minimum resolution of the layer.

Returns:
The minimum resolution of the layer.

getOpacity(){number}

src/ol/layer/base.js, line 148

Return the opacity of the layer (between 0 and 1).

Returns:
The opacity of the layer.

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

src/ol/object.js, line 172

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited experimental

src/ol/observable.js, line 84

Get the version number for this object. Each time the object is modified, its version number will be incremented.

Returns:
Revision.

getVisible(){boolean}

src/ol/layer/base.js, line 166

Return the visibility of the layer (true or false).

Returns:
The visibility of the layer.

getZIndex(){number} experimental

src/ol/layer/base.js, line 178

Return the Z-index of the layer, which is used to order layers before rendering. The default Z-index is 0.

Returns:
The Z-index of the layer.

on(type, listener, opt_this){ol.EventsKey|Array.<ol.EventsKey>} inherited

src/ol/observable.js, line 99

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. If called with an array of event types as the first argument, the return will be an array of keys.

once(type, listener, opt_this){ol.EventsKey|Array.<ol.EventsKey>} inherited

src/ol/observable.js, line 124

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. If called with an array of event types as the first argument, the return will be an array of keys.

set(key, value, opt_silent) inherited

src/ol/object.js, line 197

Sets a value.

Name Type Description
key string

Key name.

value *

Value.

silent boolean

Update without triggering an event.

setExtent(extent)

src/ol/layer/base.js, line 190

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.

setMaxResolution(maxResolution)

src/ol/layer/base.js, line 201

Set the maximum resolution at which the layer is visible.

Name Type Description
maxResolution number

The maximum resolution of the layer.

setMinResolution(minResolution)

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

Set the minimum resolution at which the layer is visible.

Name Type Description
minResolution number

The minimum resolution of the layer.

setOpacity(opacity)

src/ol/layer/base.js, line 223

Set the opacity of the layer, allowed values range from 0 to 1.

Name Type Description
opacity number

The opacity of the layer.

setProperties(values, opt_silent) inherited

src/ol/object.js, line 217

Sets a collection of key-value pairs. Note that this changes any existing properties and adds new ones (it does not remove any existing properties).

Name Type Description
values Object.<string, *>

Values.

silent boolean

Update without triggering an event.

setVisible(visible)

src/ol/layer/base.js, line 234

Set the visibility of the layer (true or false).

Name Type Description
visible boolean

The visibility of the layer.

setZIndex(zindex) experimental

src/ol/layer/base.js, line 246

Set Z-index of the layer, which is used to order layers before rendering. The default Z-index is 0.

Name Type Description
zindex number

The z-index of the layer.

un(type, listener, opt_this) inherited

src/ol/observable.js, line 147

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.

unByKey(key) inherited

src/ol/observable.js, line 168

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 ol.EventsKey | Array.<ol.EventsKey>

The key returned by on() or once() (or an array of keys).

unset(key, opt_silent) inherited

src/ol/object.js, line 231

Unsets a property.

Name Type Description
key string

Key name.

silent boolean

Unset without triggering an event.