Class: Control

ol/control/Control~Control


import Control from '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:

const myControl = new 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 objects in a 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 Control(options)

Name Type Description
element HTMLElement | 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

Function called when the control should be re-rendered. This is called in a requestAnimationFrame callback.

target HTMLElement | string | undefined

Specify a target if you want the control to be rendered outside of the map's viewport.

Fires:

Subclasses

Extends

Methods

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

dispatchEvent(event){boolean | undefined} inherited

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 BaseEvent | string

Event object.

Returns:
false if anyone called preventDefault on the event object or if any of the listeners returned false.

Gets a value.

Name Type Description
key string

Key name.

Returns:
Value.

getKeys(){Array.<string>} inherited

Get a list of object property names.

Returns:
List of property names.

getMap(){Map | null}

Get the map associated with this control.

Returns:
Map.

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

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited

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

Returns:
Revision.

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

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.

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){EventsKey | Array<EventsKey>} inherited

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.

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.

render(mapEvent)

Renders the control.

Name Type Description
mapEvent MapEvent

Map event.

set(key, value, silent) inherited

Sets a value.

Name Type Description
key string

Key name.

value *

Value.

silent boolean | undefined

Update without triggering an event.

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

Name Type Description
map Map | null

Map.

setProperties(values, silent) inherited

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 | undefined

Update without triggering an event.

setTarget(target)

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 HTMLElement | string

Target.

un(type, listener) inherited

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.

unset(key, silent) inherited

Unsets a property.

Name Type Description
key string

Key name.

silent boolean | undefined

Unset without triggering an event.