OpenLayers

Class: ScaleLine

ol.control.ScaleLine 


import ScaleLine from 'ol/control/scaleline';

A control displaying rough y-axis distances, calculated for the center of the viewport. For conformal projections (e.g. EPSG:3857, the default view projection in OpenLayers), the scale is valid for all directions. No scale line will be shown when the y-axis distance of a pixel at the viewport center cannot be calculated in the view projection. By default the scale line will show in the bottom left portion of the map, but this can be changed by using the css selector .ol-scale-line.

new ol.control.ScaleLine(opt_options)

src/ol/control/scaleline.js, line 29
Name Type Description
options

Scale line options.

Name Type Description
className string | undefined

CSS Class name. Default is ol-scale-line.
minWidth number | undefined

Minimum width in pixels. Default is 64.
render function | undefined

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.
units ol.control.ScaleLineUnits | string | undefined

Units. Default is metric.
Fires:

Extends

Observable Properties

Name Type Settable ol.Object.Event type Description
units ol.control.ScaleLineUnits | undefined yes change:units

The units to use in the scale line.

Methods

ol.control.ScaleLine.render(mapEvent)

src/ol/control/scaleline.js, line 125

Update the scale line element.

This:
Name Type Description
mapEvent ol.MapEvent

Map event.

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.

getKeys(){Array.<string>} inherited

src/ol/object.js, line 115

Get a list of object property names.

Returns:
List of property names.

getMap(){ol.PluggableMap} inherited

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 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.

getUnits(){ol.control.ScaleLineUnits|undefined}

src/ol/control/scaleline.js, line 113

Return the units to use in the scale line.

Returns:
The units to use in the scale line.

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.

setMap(map) inherited

src/ol/control/control.js, line 107

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.PluggableMap

Map.

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.

setTarget(target) inherited

src/ol/control/control.js, line 138

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.

setUnits(units)

src/ol/control/scaleline.js, line 150

Set the units to use in the scale line.

Name Type Description
units ol.control.ScaleLineUnits

The units to use in the scale line.

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.