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 69
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.
Fires:

Extends

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 301

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.

dispatchChangeEvent() inherited experimental

src/ol/observable.js, line 42

Dispatches a change event.

Fires:
  • change experimental

get(key){*} inherited experimental

src/ol/object.js, line 358

Gets a value.

Name Type Description
key string

Key name.
Returns:
Value.

getElement(){Element|undefined}

src/ol/overlay.js, line 160

Get the DOM element of this overlay.

Returns:
The Element containing the overlay.

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

src/ol/object.js, line 386

Get a list of object property names.

Returns:
List of property names.

getMap(){ol.Map|undefined}

src/ol/overlay.js, line 176

Get the map associated with this overlay.

Returns:
The map that the overlay is part of.

getOffset(){Array.<number>}

src/ol/overlay.js, line 192

Get the offset of this overlay.

Returns:
The offset.

getPosition(){ol.Coordinate|undefined}

src/ol/overlay.js, line 209

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 226

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 418

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited experimental

src/ol/observable.js, line 52
Returns:
Revision.

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

src/ol/observable.js, line 65

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 78

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 448

Sets a value.

Name Type Description
key string

Key name.
value *

Value.

setElement(element)

src/ol/overlay.js, line 312

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 327

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 342

Set the offset for this overlay.

Name Type Description
offset Array.<number>

Offset.

setPosition(position)

src/ol/overlay.js, line 358

Set the position for this overlay.

Name Type Description
position ol.Coordinate | undefined

The spatial point that the overlay is anchored at.

setPositioning(positioning)

src/ol/overlay.js, line 374

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 477

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 91

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 491

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 515

Removes all bindings.

unByKey(key) inherited

src/ol/observable.js, line 101

Removes an event listener using the key returned by on() or once().

Name Type Description
key goog.events.Key

Key.