require(["esri/widgets/LineOfSight"], (LineOfSight) => { /* code goes here */ });
import LineOfSight from "@arcgis/core/widgets/LineOfSight.js";
esri/widgets/LineOfSight
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 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. 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
Constructors
-
new LineOfSight(properties)
-
Parameterproperties 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 |
---|---|---|---|
LineOfSightAnalysis | The line of sight analysis object being created or modified by the widget. more details | LineOfSight | |
String|HTMLElement | The ID or node representing the DOM element containing the widget. more details | Widget | |
String | The name of the class. more details | Accessor | |
String | Icon which represents the widget. more details | LineOfSight | |
String | The widget's default CSS icon class. more details | LineOfSight | |
String | The unique ID assigned to the widget when the widget is created. more details | Widget | |
String | The widget's default label. more details | LineOfSight | |
SceneView | A reference to the SceneView. more details | LineOfSight | |
LineOfSightViewModel | The view model for this widget. more details | LineOfSight | |
Boolean | Indicates whether the widget is visible. more details | Widget |
Property Details
-
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.
This property can be set during widget construction, to provide an existing analysis to the widget for modification. Properties on the analysis can also be modified once it's assigned to the widget.
If no analysis is provided during widget construction, 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 widget const 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 view view.analyses.add(analysis); // Frame the analysis in the view view.goTo(analysis.extent); // Pass the analysis object as a constructor parameter to modify it using the widget const viewModel = new LineOfSight({ analysis: analysis, view: view });
-
-
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
.
-
icon StringSince: 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:null
- See also
-
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.
-
label String
-
The widget's default label.
-
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.
-
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 view UI, 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 view widget.visible = false;
Method Overview
Name | Return Type | Summary | Class |
---|---|---|---|
Adds one or more handles which are to be tied to the lifecycle of the object. more details | Accessor | ||
String | A utility method used for building the value for a widget's | Widget | |
Destroys the widget instance. more details | Widget | ||
Boolean | Emits an event on the instance. more details | Widget | |
Boolean | Indicates whether there is an event listener on the instance that matches the provided event name. more details | Widget | |
Boolean | Returns true if a named group of handles exist. more details | Accessor | |
Boolean |
| Widget | |
Boolean |
| Widget | |
Boolean |
| Widget | |
Object | Registers an event handler on the instance. more details | Widget | |
Adds one or more handles which are to be tied to the lifecycle of the widget. more details | Widget | ||
This method is primarily used by developers when implementing custom widgets. more details | Widget | ||
Removes a group of handles owned by the object. more details | Accessor | ||
Object | This method is primarily used by developers when implementing custom widgets. more details | Widget | |
Renders widget to the DOM immediately. more details | Widget | ||
This method is primarily used by developers when implementing custom widgets. more details | Widget | ||
Promise |
| Widget |
Method Details
-
addHandles(handleOrHandles, groupKey)inheritedSince: ArcGIS Maps SDK for JavaScript 4.25
-
Adds one or more handles which are to be tied to the lifecycle of the object. The handles will be removed when the object is destroyed.
// Manually manage handles const handle = reactiveUtils.when( () => !view.updating, () => { wkidSelect.disabled = false; }, { once: true } ); this.addHandles(handle); // Destroy the object this.destroy();
ParametershandleOrHandles WatchHandle|WatchHandle[]Handles marked for removal once the object is destroyed.
groupKey *optionalKey identifying the group to which the handles should be added. All the handles in the group can later be removed with Accessor.removeHandles(). If no key is provided the handles are added to a default group.
-
A utility method used for building the value for a widget's
class
property. This aids in simplifying css class setup.Parameterrepeatable The class names.
ReturnsType 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)} /> ); }
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destroy()inherited
-
Destroys the widget instance.
-
Emits an event on the instance. This method should only be used when creating subclasses of this class.
Parameterstype StringThe name of the event.
event ObjectoptionalThe event payload.
ReturnsType Description Boolean true
if a listener was notified
-
Indicates whether there is an event listener on the instance that matches the provided event name.
Parametertype StringThe name of the event.
ReturnsType Description Boolean Returns true if the class supports the input event.
-
Since: ArcGIS Maps SDK for JavaScript 4.25
-
Returns true if a named group of handles exist.
ParametergroupKey *optionalA group key.
ReturnsType Description Boolean Returns true
if a named group of handles exist.Example// Remove a named group of handles if they exist. if (obj.hasHandles("watch-view-updates")) { obj.removeHandles("watch-view-updates"); }
-
Since: ArcGIS Maps SDK for JavaScript 4.19
-
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.ReturnsType Description Boolean Indicates whether creating an instance of the class has been fulfilled (either resolved or rejected).
-
Since: ArcGIS Maps SDK for JavaScript 4.19
-
isRejected()
may be used to verify if creating an instance of the class is rejected. If it is rejected,true
will be returned.ReturnsType Description Boolean Indicates whether creating an instance of the class has been rejected.
-
Since: ArcGIS Maps SDK for JavaScript 4.19
-
isResolved()
may be used to verify if creating an instance of the class is resolved. If it is resolved,true
will be returned.ReturnsType Description Boolean Indicates whether creating an instance of the class has been resolved.
-
Registers an event handler on the instance. Call this method to hook an event with a listener.
ParametersAn event or an array of events to listen for.
listener FunctionThe function to call when the event fires.
ReturnsType Description Object 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. Exampleview.on("click", function(event){ // event is the event handle returned after the event fires. console.log(event.mapPoint); });
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own(handleOrHandles)inheritedSince: ArcGIS Maps SDK for JavaScript 4.24Deprecated since 4.28 Use addHandles() instead.
-
Adds one or more handles which are to be tied to the lifecycle of the widget. The handles will be removed when the widget is destroyed.
const handle = reactiveUtils.when( () => !view.updating, () => { wkidSelect.disabled = false; }, { once: true} ); this.own(handle); // Handle gets removed when the widget is destroyed.
ParameterhandleOrHandles 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.
-
removeHandles(groupKey)inheritedSince: ArcGIS Maps SDK for JavaScript 4.25
-
Removes a group of handles owned by the object.
ParametergroupKey *optionalA group key or an array or collection of group keys to remove.
Exampleobj.removeHandles(); // removes handles from default group obj.removeHandles("handle-group"); obj.removeHandles("other-handle-group");
-
This method is primarily used by developers when implementing custom widgets. It must be implemented by subclasses for rendering.
ReturnsType 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.
-
Since: ArcGIS Maps SDK for JavaScript 4.19
-
when()
may be leveraged once an instance of the class is created. This method takes two input parameters: acallback
function and anerrback
function. Thecallback
executes when the instance of the class loads. Theerrback
executes if the instance of the class fails to load.Parameterscallback FunctionoptionalThe function to call when the promise resolves.
errback FunctionoptionalThe function to execute when the promise fails.
ReturnsType Description Promise Returns a new promise for the result of callback
.Example// Although this example uses the BasemapGallery widget, any class instance that is a promise may use when() in the same way let bmGallery = new BasemapGallery(); bmGallery.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 });