OpenLayers 3 API Documentation

Class: Overlay

ol.Overlay

Like ol.control.Control, Overlays are visible widgets. Unlike Controls, they are not in a fixed position on the screen, but are tied to a geographical coordinate, so panning the map will move an Overlay but not a Control.

Example:

var popup = new ol.Overlay({
  element: document.getElementById('popup')
});
popup.setPosition(coordinate);
map.addOverlay(popup);

new ol.Overlay(options)

src/ol/overlay.js, line 72

Name Type Description

options

Overlay options.

Name	Type	Description
`element`	Element \| undefined	The overlay element.
`offset`	Array.<number> \| undefined	Offsets in pixels used when positioning the overlay. The fist element in the array is the horizontal offset. A positive value shifts the overlay right. The second element in the array is the vertical offset. A positive value shifts the overlay down. Default is `[0, 0]`.
`position`	ol.Coordinate \| undefined	The overlay position in map projection.
`positioning`	ol.OverlayPositioning \| string \| undefined	Defines how the overlay is actually positioned with respect to its `position` property. Possible values are `'bottom-left'`, `'bottom-center'`, `'bottom-right'`, `'center-left'`, `'center-center'`, `'center-right'`, `'top-left'`, `'top-center'`, and `'top-right'`. Default is `'top-left'`.
`stopEvent`	boolean \| undefined	Whether event propagation to the map viewport should be stopped. Default is `true`. If `true` the overlay is placed in the same container as that of the controls (CSS class name `ol-overlaycontainer-stopevent`); if `false` it is placed in the container with CSS class name `ol-overlaycontainer`.
`insertFirst`	boolean \| undefined	Whether the overlay is inserted first in the overlay container, or appended. Default is `true`. If the overlay is placed in the same container as that of the controls (see the `stopEvent` option) you will probably set `insertFirst` to `true` so the overlay is displayed below the controls.
`autoPan`	boolean \| undefined	experimental If set to `true` the map is panned when calling `setPosition`, so that the overlay is entirely visible in the current viewport. The default is `false`.
`autoPanAnimation`	olx.animation.PanOptions \| undefined	experimental The options used to create a `ol.animation.pan` animation. This animation is only used when `autoPan` is enabled. By default the default options for `ol.animation.pan` are used. If set to `null` the panning is not animated.
`autoPanMargin`	number \| undefined	experimental The margin (in pixels) between the overlay and the borders of the map when autopanning. The default is `20`.

Fires:

change:element (ol.ObjectEvent)
change:map (ol.ObjectEvent)
change:offset (ol.ObjectEvent)
change:position (ol.ObjectEvent)
change:positioning (ol.ObjectEvent)
propertychange (ol.ObjectEvent) experimental - Triggered when a property is changed.

Extends

ol.Object

Observable Properties

Name	Type	Settable	ol.ObjectEvent type	Description
`element`	Element \| undefined	yes	`change:element`	The Element containing the overlay.
`map`	ol.Map \| undefined	yes	`change:map`	The map that the overlay is part of.
`offset`	Array.<number>	yes	`change:offset`	The offset.
`position`	ol.Coordinate \| undefined	yes	`change:position`	The spatial point that the overlay is anchored at.
`positioning`	ol.OverlayPositioning	yes	`change:positioning`	How the overlay is positioned relative to its point on the map.

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.

getElement(){Element|undefined} src/ol/overlay.js, line 182

Get the DOM element of this overlay.

Returns:

The Element containing the overlay.

getKeys(){Array.<string>} inherited experimental src/ol/object.js, line 373

Get a list of object property names.

Returns:

List of property names.

getMap(){ol.Map|undefined} src/ol/overlay.js, line 198

Get the map associated with this overlay.

Returns:

The map that the overlay is part of.

getOffset(){Array.<number>} src/ol/overlay.js, line 214

Get the offset of this overlay.

Returns:

The offset.

getPosition(){ol.Coordinate|undefined} src/ol/overlay.js, line 231

Get the current position of this overlay.

Returns:

The spatial point that the overlay is anchored at.

getPositioning(){ol.OverlayPositioning} src/ol/overlay.js, line 248

Get the current positioning of this overlay.

Returns:

How the overlay is positioned relative to its point on the map.

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.

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.

setElement(element) src/ol/overlay.js, line 337

Set the DOM element to be associated with this overlay.

Name	Type	Description
`element`	Element \| undefined	The Element containing the overlay.

setMap(map) src/ol/overlay.js, line 352

Set the map to be associated with this overlay.

Name	Type	Description
`map`	ol.Map \| undefined	The map that the overlay is part of.

setOffset(offset) src/ol/overlay.js, line 367

Set the offset for this overlay.

Name	Type	Description
`offset`	Array.<number>	Offset.

setPosition(position) src/ol/overlay.js, line 384

Set the position for this overlay. If the position is undefined the overlay is hidden.

Name	Type	Description
`position`	ol.Coordinate \| undefined	The spatial point that the overlay is anchored at.

setPositioning(positioning) src/ol/overlay.js, line 483

Set the positioning for this overlay.

Name	Type	Description
`positioning`	ol.OverlayPositioning	how the overlay is positioned relative to its point on the map.

setProperties(values) inherited experimental src/ol/object.js, line 456

Sets a collection of key-value pairs.

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

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()`.