OpenLayers 3

Class: Control

ol.control.Control

A control is a visible widget with a DOM element in a fixed position on the screen. They can involve user input (buttons), or be informational only; the position is determined using CSS. By default these are placed in the container with CSS class name ol-overlaycontainer-stopevent, but can use any outside DOM element.

This is the base class for controls. You can use it for simple custom controls by creating the element with listeners, creating an instance:

var myControl = new ol.control.Control({element: myElement});

and then adding this to the map.

The main advantage of having this as a control rather than a simple separate DOM element is that preventing propagation is handled for you. Controls will also be ol.Objects in a ol.Collection, so you can use their methods.

You can also extend this base for your own control class. See examples/custom-controls for an example of how to do this.

new ol.control.Control(options)

src/ol/control/control.js, line 39
Name Type Description
options

Control options.

Name Type Description
element Element | undefined

The element is the control's container element. This only needs to be specified if you're developing a custom control.
render function | undefined experimental

Function called when the control should be re-rendered. This is called in a requestAnimationFrame callback.
target Element | string | undefined

Specify a target if you want the control to be rendered outside of the map's viewport.
Fires:
  • change experimental - Triggered when the revision counter is increased.
  • propertychange (ol.ObjectEvent) - Triggered when a property is changed.

Subclasses

Extends

Methods

changed() inherited experimental

src/ol/observable.js, line 50

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

dispatchEvent(event) inherited experimental

src/ol/observable.js, line 72

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 goog.events.EventLike

Event object.

get(key){*} inherited

src/ol/object.js, line 147

Gets a value.

Name Type Description
key string

Key name.
Returns:
Value.

getKeys(){Array.<string>} inherited

src/ol/object.js, line 161

Get a list of object property names.

Returns:
List of property names.

getMap(){ol.Map}

src/ol/control/control.js, line 94

Get the map associated with this control.

Returns:
Map.

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

src/ol/object.js, line 171

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited experimental

src/ol/observable.js, line 81

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

Returns:
Revision.

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

src/ol/observable.js, line 94

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 107

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, opt_silent) inherited

src/ol/object.js, line 201

Sets a value.

Name Type Description
key string

Key name.
value *

Value.
silent boolean

Update without triggering an event.

setMap(map)

src/ol/control/control.js, line 106

Remove the control from its current map and attach it to the new map. Subclasses may set up event handlers to get notified about changes to the map here.

Name Type Description
map ol.Map

Map.

setProperties(values, opt_silent) inherited

src/ol/object.js, line 221

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.

setTarget(target) experimental

src/ol/control/control.js, line 137

This function is used to set a target element for the control. It has no effect if it is called after the control has been added to the map (i.e. after setMap is called on the control). If no target is set in the options passed to the control constructor and if setTarget is not called then the control is added to the map's overlay container.

Name Type Description
target Element | string

Target.

un(type, listener, opt_this) inherited

src/ol/observable.js, line 120

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 133

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().

unset(key, opt_silent) inherited

src/ol/object.js, line 235

Unsets a property.

Name Type Description
key string

Key name.
silent boolean

Unset without triggering an event.