OpenLayers

Class: KeyboardZoom

ol.interaction.KeyboardZoom

Allows the user to zoom the map using keyboard + and -. Note that, although this interaction is by default included in maps, the keys can only be used when browser focus is on the element to which the keyboard events are attached. By default, this is the map div, though you can change this with the keyboardEventTarget in ol.Map. document never loses focus but, for any other element, focus will have to be on, and returned to, this element if the keys are to function. See also ol.interaction.KeyboardPan.

new ol.interaction.KeyboardZoom(opt_options)

src/ol/interaction/keyboardzoom.js, line 26
Name Type Description
options

Options.

Name Type Description
duration number | undefined

Animation duration in milliseconds. Default is 100.
condition ol.EventsConditionType | undefined

A function that takes an ol.MapBrowserEvent and returns a boolean to indicate whether that event should be handled. Default is ol.events.condition.targetNotEditable.
delta number | undefined

The amount to zoom on each key press. Default is 1.
Fires:

Extends

Observable Properties

Name Type Settable ol.Object.Event type Description
active boolean yes change:active

true if the interaction is active, false otherwise.

Methods

ol.interaction.KeyboardZoom.handleEvent(mapBrowserEvent){boolean}

src/ol/interaction/keyboardzoom.js, line 66

Handles the map browser event if it was a KeyEvent, and decides whether to zoom in or out (depending on whether the key pressed was '+' or '-').

This:
Name Type Description
mapBrowserEvent ol.MapBrowserEvent

Map browser event.
Returns:
false to stop event propagation.

changed() inherited

src/ol/observable.js, line 58

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

dispatchEvent(event) inherited

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 101

Gets a value.

Name Type Description
key string

Key name.
Returns:
Value.

getActive(){boolean} inherited

src/ol/interaction/interaction.js, line 55

Return whether the interaction is currently active.

Returns:
true if the interaction is active, false otherwise.

getKeys(){Array.<string>} inherited

src/ol/object.js, line 115

Get a list of object property names.

Returns:
List of property names.

getMap(){ol.Map} inherited

src/ol/interaction/interaction.js, line 66

Get the map associated with this interaction.

Returns:
Map.

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

src/ol/object.js, line 125

Get an object of all property names and values.

Returns:
Object.

getRevision(){number} inherited

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.

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 150

Sets a value.

Name Type Description
key string

Key name.
value *

Value.
silent boolean

Update without triggering an event.

setActive(active) inherited

src/ol/interaction/interaction.js, line 77

Activate or deactivate the interaction.

Name Type Description
active boolean

Active.

setProperties(values, opt_silent) inherited

src/ol/object.js, line 170

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.

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.

unset(key, opt_silent) inherited

src/ol/object.js, line 184

Unsets a property.

Name Type Description
key string

Key name.
silent boolean

Unset without triggering an event.