LineOfSight
require(["esri/widgets/LineOfSight"], function(LineOfSight) { /* code goes here */ });esri/widgets/LineOfSightThe 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 view
view.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.
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 line of sight are temporary and cannot be persisted in a WebScene or in slides.
- See also:
Constructors
- new LineOfSight(properties)
- Parameter:properties Objectoptional
See the properties for a list of all the properties that may be passed into the constructor.
Example:// typical usage const lineOfSight = new LineOfSight({ view: view });
Property Overview
| Name | Type | Summary | Class | |
|---|---|---|---|---|
| String|HTMLElement | The ID or node representing the DOM element containing the widget. more details | more details | Widget | |
| String | The name of the class. more details | more details | Accessor | |
| Boolean | When | more details | Widget | |
| String | The unique ID assigned to the widget when the widget is created. more details | more details | Widget | |
| String | The widget's label. more details | more details | Widget | |
| SceneView | A reference to the SceneView. more details | more details | LineOfSight | |
| LineOfSightViewModel | The view model for this widget. more details | more details | LineOfSight |
Property Details
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 cases when working with widgets.
Examples:// Create the HTML div element programmatically at runtime and set to the widget's container const basemapGallery = new BasemapGallery({ view: view, container: document.createElement("div") }); // Add the widget to the top-right corner of the view view.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 view view.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 UI const basemapGallery = new BasemapGallery({ view: view }); // Add the widget to the top-right corner of the view view.ui.add(basemapGallery, { position: "top-right" });
The name of the class. The declared class name is formatted as
esri.folder.className.
When
true, this property indicates whether the widget has been destroyed.
The unique ID assigned to the widget when the widget is created. If not set by the developer, it will default to the container ID, or if that is not present then it will be automatically generated.
The widget's label.
This property is useful whenever the widget is controlled by another one (e.g. Expand)
- viewModel LineOfSightViewModelautocast
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.
Method Overview
| Name | Return Type | Summary | Class | |
|---|---|---|---|---|
| String | A utility method used for building the value for a widget's | more details | Widget | |
Destroys the widget instance. more details | more details | Widget | ||
| Boolean | Emits an event on the instance. more details | more details | Widget | |
| Boolean | Indicates whether there is an event listener on the instance that matches the provided event name. more details | more details | Widget | |
| Object | Registers an event handler on the instance. more details | more details | Widget | |
Widget teardown helper. more details | more details | Widget | ||
This method is primarily used by developers when implementing custom widgets. more details | more details | Widget | ||
| Object | This method is primarily used by developers when implementing custom widgets. more details | more details | Widget | |
Renders widget to the DOM immediately. more details | more details | Widget | ||
This method is primarily used by developers when implementing custom widgets. more details | more details | Widget |
Method Details
A utility method used for building the value for a widget's
classproperty. This aids in simplifying CSS class setup.Parameter:repeatable The class names.
Returns:Type Description String The computed class name. Example:// .tsx syntax showing how to set CSS classes while rendering the widget render() { const dynamicIconClasses = { [CSS.myIcon]: this.showIcon, [CSS.greyIcon]: !this.showIcon }; return ( <div class={classes(CSS.root, CSS.mixin, dynamicIconClasses)} /> ); }
- destroy()inherited
Destroys the widget instance.
Emits an event on the instance. This method should only be used when creating subclasses of this class.
Parameters:type StringThe name of the event.
event ObjectoptionalThe event payload.
Returns:Type Description Boolean trueif a listener was notified
Indicates whether there is an event listener on the instance that matches the provided event name.
Parameter:type StringThe name of the event.
Returns:Type Description Boolean Returns true if the class supports the input event.
Registers an event handler on the instance. Call this method to hook an event with a listener.
Parameters:A event type, or an array of event types, to listen for.
listener FunctionThe function to call when the event is fired.
Returns:Type Description Object Returns an event handler with a remove()method that can 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); });
- own(handles)inherited
Widget teardown helper. Any handles added to it will be automatically removed when the widget is destroyed.
Parameter:handles WatchHandle|WatchHandle[]Handles marked for removal once the widget is destroyed.
- postInitialize()inherited
This method is primarily used by developers when implementing custom widgets. Executes after widget is ready for rendering.
This method is primarily used by developers when implementing custom widgets. It must be implemented by subclasses for rendering.
Returns:Type Description Object The rendered virtual node.
- renderNow()inherited
Renders widget to the DOM immediately.
- scheduleRender()inherited
This method is primarily used by developers when implementing custom widgets. Schedules widget rendering. This method is useful for changes affecting the UI.