import LineOfSight from "@arcgis/core/widgets/LineOfSight.js";const LineOfSight = await $arcgis.import("@arcgis/core/widgets/LineOfSight.js");- Inheritance:
- LineOfSight→
Widget<LineOfSightProperties>→ Accessor
- Since
- ArcGIS Maps SDK for JavaScript 4.14
The LineOfSight widget is a 3D analysis tool that allows you to perform visibility analysis in a SceneView. Visibility between a given observer and multiple target points is calculated against the currently displayed content in the view, including ground, integrated meshes and 3D objects such as buildings or trees.
The results from the analysis are displayed as lines, where the visible part, indicating what the observer can see, is colored green. Occluded targets are displayed as a red sphere, and the occluded part of the line of sight is also displayed in red. Visible targets are displayed with a green sphere, and a fully green line of sight. When the line of sight can't be calculated, it will be displayed with a gray color. This happens when either the target or the observer are not in the view, or when neither of them are in the view.
To use the widget, instantiate it and add it to the view:
const lineOfSight = new LineOfSight({ view: view});
// Add widget to the bottom left corner of the viewview.ui.add(lineOfSight, { position: "bottom-left"});With the interactive widget you can click once in the scene to set the observer, and then click again to set one or multiple targets. Both observer and target points can be moved by dragging them. Remove a target with right click.
Using the LineOfSightViewModel you can also set the observer and targets programmatically. Read more about it in the LineOfSightViewModel documentation or explore the code in the Line of sight sample.
LineOfSight only works with SceneView. The results displayed by the widget can be saved to a WebScene by assigning the analysis to a LineOfSightLayer.
- See also
LineOfSightViewModel - Deprecated since 4.33. Use the LineOfSightAnalysis or Line Of Sight component instead.
Constructors
Constructor
Parameters
| Parameter | Type | Description | Required |
|---|---|---|---|
| properties | | |
Example
// typical usageconst lineOfSight = new LineOfSight({ view: view});Properties
| Property | Type | Class |
|---|---|---|
| | ||
container inherited | HTMLElement | null | undefined | |
declaredClass readonly inherited | ||
destroyed readonly inherited | ||
Icon["icon"] | | |
id inherited | ||
| | ||
| | ||
| | ||
visible inherited |
analysis
- Type
- LineOfSightAnalysis
- Since
- ArcGIS Maps SDK for JavaScript 4.23
The line of sight analysis object being created or modified by the widget. This property is an alias for LineOfSightViewModel.analysis.
If no analysis is provided, the widget automatically creates its own analysis and adds it to the view. In this case, the analysis will also be automatically removed from the view when the widget is destroyed.
- See also
Example
// Construct a line of sight analysis object outside of the widgetconst analysis = new LineOfSightAnalysis({ observer: { type: "point", // autocasts as new Point() x: 7.67, y: 45.981, z: 3435.765 }, targets: [{ location: { type: "point", x: 7.659, y: 45.976, z: 4437 } }]});
// Ensure that the analysis is added to the viewview.analyses.add(analysis);
// Frame the analysis in the viewview.goTo(analysis.extent);
// Pass the analysis object as a constructor parameter to modify it using the widgetconst viewModel = new LineOfSight({ analysis: analysis, view: view}); 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. It is typically used when the widget is controlled by another one (e.g. in the Expand widget).
- Default value
- "line-of-sight"
viewModel
- Type
- LineOfSightViewModel
The view model for this widget. This is a class that contains the properties and methods that control this widget's behavior. See the LineOfSightViewModel 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
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>>
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>
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});