import ScaleBar from "@arcgis/core/widgets/ScaleBar.js";const ScaleBar = await $arcgis.import("@arcgis/core/widgets/ScaleBar.js");- Since
- ArcGIS Maps SDK for JavaScript 4.3
The ScaleBar widget displays a scale bar on the map or in a specified HTML node. The widget respects various coordinate systems and displays units in metric or imperial values. Metric values show either kilometers, meters, centimeters, or millimeters depending on the scale, and likewise, imperial values show miles, feet, or inches depending on the scale. When working with Web Mercator or geographic coordinate systems the scale bar takes into account projection distortion and dynamically adjusts the scale bar.
When the scale bar is inside the map, the actual location of the scale bar is used to calculate the scale. Otherwise, the center of the map is used to calculate the scale.
Known Limitations
ScaleBar only works with MapView.
- See also
Example
let scaleBar = new ScaleBar({ view: view});// Add widget to the bottom left corner of the viewview.ui.add(scaleBar, { position: "bottom-left"});Constructors
Constructor
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
| properties | | |
Example
// typical usagelet scalebar = new ScaleBar({ view: view});Properties
| Property | Type | Class |
|---|---|---|
container inherited | HTMLElement | null | undefined | |
declaredClass readonly inherited | ||
destroyed readonly inherited | ||
Icon["icon"] | | |
id inherited | ||
| | ||
| | ||
| | ||
| | ||
| | ||
visible inherited |
container
- Type
- HTMLElement | null | undefined
The ID or node representing the DOM element containing the widget. This property can only be set once. The following examples are all valid use case when working with widgets.
Examples
// Create the HTML div element programmatically at runtime and set to the widget's containerconst basemapGallery = new BasemapGallery({ view: view, container: document.createElement("div")});
// Add the widget to the top-right corner of the viewview.ui.add(basemapGallery, { position: "top-right"});// Specify an already-defined HTML div element in the widget's container
const basemapGallery = new BasemapGallery({ view: view, container: basemapGalleryDiv});
// Add the widget to the top-right corner of the viewview.ui.add(basemapGallery, { position: "top-right"});
// HTML markup<body> <div id="viewDiv"></div> <div id="basemapGalleryDiv"></div></body>// Specify the widget while adding to the view's UIconst basemapGallery = new BasemapGallery({ view: view});
// Add the widget to the top-right corner of the viewview.ui.add(basemapGallery, { position: "top-right"}); icon
- Type
- Icon["icon"]
- Since
- ArcGIS Maps SDK for JavaScript 4.27
Icon which represents the widget. Typically used when the widget is controlled by another widget (e.g. by the Expand widget).
- Default value
- "actual-size"
style
- Type
- ScaleBarStyle
The style for the scale bar.
When unit is set to dual, the style will always be line.
- Default value
- "line"
unit
- Type
- ScaleBarUnit
Units to use for the scale bar.
When using dual, the scale bar displays both metric and imperial units.
When metric, distances will be shown in either kilometers, meters, centimeters, or millimeters depending on the scale. Similarly, imperial
units will be shown in either miles, feet, or inches.
viewModel
- Type
- ScaleBarViewModel
The view model for this widget. This is a class that contains all the logic (properties and methods) that controls this widget's behavior. See the ScaleBarViewModel class to access all properties and methods on the widget.
visible
- Type
- boolean
Indicates whether the widget is visible.
If false, the widget will no longer be rendered in the web document. This may affect the layout of other elements or widgets in the document. For example, if this widget is
the first of three widgets associated to the upper right hand corner of the DefaultUI, then the other widgets will reposition when this widget is made invisible.
For more information, refer to the css display value of "none".
- Default value
- true
Example
// Hides the widget in the viewwidget.visible = false;Methods
| Method | Signature | Class |
|---|---|---|
classes inherited | classes(...classNames: ((string | null | undefined) | ((string[] | Record<string, boolean>) | null | undefined) | false | null | undefined)[]): string | |
destroy inherited | destroy(): void | |
emit inherited | emit<Type extends EventNames<this>>(type: Type, event?: this["@eventTypes"][Type]): boolean | |
hasEventListener inherited | hasEventListener<Type extends EventNames<this>>(type: Type): boolean | |
isFulfilled inherited | isFulfilled(): boolean | |
isRejected inherited | isRejected(): boolean | |
isResolved inherited | isResolved(): boolean | |
on inherited | on<Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle | |
postInitialize inherited | postInitialize(): void | |
render inherited | render(): any | null | |
renderNow inherited | renderNow(): void | |
scheduleRender inherited | scheduleRender(): void | |
when inherited | when<TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> | null | undefined, onRejected?: OnRejectedCallback<TResult2> | null | undefined): Promise<TResult1 | TResult2> |
classes
- Signature
-
classes (...classNames: ((string | null | undefined) | ((string[] | Record<string, boolean>) | null | undefined) | false | null | undefined)[]): string
- Since
- ArcGIS Maps SDK for JavaScript 4.7
A utility method used for building the value for a widget's class property.
This aids in simplifying css class setup.
Parameters
- Returns
- string
The computed class name.
Example
// .tsx syntax showing how to set css classes while rendering the widget
render() { const dynamicClasses = { [css.flip]: this.flip, [css.primary]: this.primary };
return ( <div class={classes(css.root, css.mixin, dynamicClasses)} /> );} emit
- Signature
-
emit <Type extends EventNames<this>>(type: Type, event?: this["@eventTypes"][Type]): boolean
- Type parameters
- <Type extends EventNames<this>>
- Since
- ArcGIS Maps SDK for JavaScript 4.5
Emits an event on the instance. This method should only be used when creating subclasses of this class.
hasEventListener
- Signature
-
hasEventListener <Type extends EventNames<this>>(type: Type): boolean
- Type parameters
- <Type extends EventNames<this>>
Indicates whether there is an event listener on the instance that matches the provided event name.
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
| type | Type | The name of the event. | |
- Returns
- boolean
Returns true if the class supports the input event.
isFulfilled
- Signature
-
isFulfilled (): boolean
isFulfilled() may be used to verify if creating an instance of the class is fulfilled (either resolved or rejected).
If it is fulfilled, true will be returned.
- Returns
- boolean
Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected).
isRejected
- Signature
-
isRejected (): boolean
isRejected() may be used to verify if creating an instance of the class is rejected.
If it is rejected, true will be returned.
- Returns
- boolean
Indicates whether creating an instance of the class has been rejected.
isResolved
- Signature
-
isResolved (): boolean
isResolved() may be used to verify if creating an instance of the class is resolved.
If it is resolved, true will be returned.
- Returns
- boolean
Indicates whether creating an instance of the class has been resolved.
on
- Signature
-
on <Type extends EventNames<this>>(type: Type, listener: EventedCallback<this["@eventTypes"][Type]>): ResourceHandle
- Type parameters
- <Type extends EventNames<this>>
Registers an event handler on the instance. Call this method to hook an event with a listener.
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
| type | Type | An event or an array of events to listen for. | |
| listener | EventedCallback<this["@eventTypes"][Type]> | The function to call when the event fires. | |
- Returns
- ResourceHandle
Returns an event handler with a
remove()method that should be called to stop listening for the event(s).Property Type Description remove Function When called, removes the listener from the event.
Example
view.on("click", function(event){ // event is the event handle returned after the event fires. console.log(event.mapPoint);}); when
- Signature
-
when <TResult1 = this, TResult2 = never>(onFulfilled?: OnFulfilledCallback<this, TResult1> | null | undefined, onRejected?: OnRejectedCallback<TResult2> | null | undefined): Promise<TResult1 | TResult2>
- Since
- ArcGIS Maps SDK for JavaScript 4.6
when() may be leveraged once an instance of the class is created. This method takes two input parameters: an onFulfilled function and an onRejected function.
The onFulfilled executes when the instance of the class loads. The
onRejected executes if the instance of the class fails to load.
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
| onFulfilled | OnFulfilledCallback<this, TResult1> | null | undefined | The function to call when the promise resolves. | |
| onRejected | The function to execute when the promise fails. | |
- Returns
- Promise<TResult1 | TResult2>
Returns a new promise for the result of
onFulfilledthat may be used to chain additional functions.
Example
// Although this example uses MapView, any class instance that is a promise may use when() in the same waylet view = new MapView();view.when(function(){ // This function will execute once the promise is resolved}, function(error){ // This function will execute if the promise is rejected due to an error});Type definitions
ScaleBarUnit
- Type
- MeasurementSystem | "dual"