require(["esri/widgets/ScaleBar"], (ScaleBar) => { /* code goes here */ });
import ScaleBar from "@arcgis/core/widgets/ScaleBar.js";
esri/widgets/ScaleBar
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. The ScaleBar widget sample, which uses a map that has the Web Mercator projection, shows this behavior. Open the sample and note that as you pan the map south towards the equator the scale bar gets shorter and as you pan north it gets longer.
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.
let scaleBar = new ScaleBar({
view: view
});
// Add widget to the bottom left corner of the view
view.ui.add(scaleBar, {
position: "bottom-left"
});
Constructors
-
Parameterproperties Objectoptional
See the properties for a list of all the properties that may be passed into the constructor.
Example// typical usage let scalebar = new ScaleBar({ view: view });
Property Overview
Name | Type | Summary | Class |
---|---|---|---|
The ID or node representing the DOM element containing the widget. | Widget | ||
The name of the class. | Accessor | ||
Icon displayed in the widget's button. | ScaleBar | ||
The unique ID assigned to the widget when the widget is created. | Widget | ||
The widget's default label. | ScaleBar | ||
The style for the scale bar. | ScaleBar | ||
Units to use for the scale bar. | ScaleBar | ||
A reference to the MapView. | ScaleBar | ||
The view model for this widget. | ScaleBar | ||
Indicates whether the widget is visible. | Widget |
Property Details
-
container
InheritedPropertycontainer String |HTMLElement
Inherited from Widget -
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 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" });
-
icon
icon String
Since: ArcGIS Maps SDK for JavaScript 4.27ScaleBar since 4.3, icon added at 4.27. -
Icon displayed in the widget's button.
- Default Value:"actual-size"
- See also
-
label
label String
-
The widget's default label.
-
style
style String
-
The style for the scale bar. When
unit
is set todual
, the style will always beline
.Possible Values:"ruler" |"line"
- Default Value:"line"
-
unit
unit String
-
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.Possible Values:"metric" |"imperial" |"dual"
-
viewModel
viewModel ScaleBarViewModelautocast
-
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
InheritedPropertyvisible Boolean
Inherited from 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. | Accessor | ||
A utility method used for building the value for a widget's | Widget | ||
Destroys the widget instance. | Widget | ||
Emits an event on the instance. | Widget | ||
Indicates whether there is an event listener on the instance that matches the provided event name. | Widget | ||
Returns true if a named group of handles exist. | Accessor | ||
| Widget | ||
| Widget | ||
| Widget | ||
Registers an event handler on the instance. | Widget | ||
Adds one or more handles which are to be tied to the lifecycle of the widget. | Widget | ||
Executes after widget is ready for rendering. | Widget | ||
Removes a group of handles owned by the object. | Accessor | ||
This method is implemented by subclasses for rendering. | Widget | ||
Renders widget to the DOM immediately. | Widget | ||
Schedules widget rendering. | Widget | ||
Promise |
| Widget |
Method Details
-
Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, addHandles added at 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.
-
classes
InheritedMethodclasses(classNames){String}
Inherited from WidgetSince: ArcGIS Maps SDK for JavaScript 4.7Widget since 4.2, classes added at 4.7. -
A utility method used for building the value for a widget's
class
property. This aids in simplifying css class setup.ReturnsType Description 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)} /> ); }
-
Inherited from Widget
-
Destroys the widget instance.
-
emit
InheritedMethodemit(type, event){Boolean}
Inherited from WidgetSince: ArcGIS Maps SDK for JavaScript 4.5Widget since 4.2, emit added at 4.5. -
Emits an event on the instance. This method should only be used when creating subclasses of this class.
ReturnsType Description Boolean true
if a listener was notified
-
hasEventListener
InheritedMethodhasEventListener(type){Boolean}
Inherited from Widget -
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.
-
hasHandles
InheritedMethodhasHandles(groupKey){Boolean}
Inherited from AccessorSince: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, hasHandles added at 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"); }
-
isFulfilled
InheritedMethodisFulfilled(){Boolean}
Inherited from WidgetSince: ArcGIS Maps SDK for JavaScript 4.19Widget since 4.2, isFulfilled added at 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).
-
isRejected
InheritedMethodisRejected(){Boolean}
Inherited from WidgetSince: ArcGIS Maps SDK for JavaScript 4.19Widget since 4.2, isRejected added at 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.
-
isResolved
InheritedMethodisResolved(){Boolean}
Inherited from WidgetSince: ArcGIS Maps SDK for JavaScript 4.19Widget since 4.2, isResolved added at 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.
-
on
InheritedMethodon(type, listener){Object}
Inherited from Widget -
Registers an event handler on the instance. Call this method to hook an event with a listener.
ParametersReturnsType 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); });
-
Inherited from Widget
Since: ArcGIS Maps SDK for JavaScript 4.24Widget since 4.2, own added at 4.24. Deprecated 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.
-
Inherited from Widget
-
Executes after widget is ready for rendering.
-
Inherited from Accessor
Since: ArcGIS Maps SDK for JavaScript 4.25Accessor since 4.0, removeHandles added at 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");
-
Inherited from Widget
-
Renders widget to the DOM immediately.
-
Inherited from Widget
-
Schedules widget rendering. This method is useful for changes affecting the UI.
-
Inherited from Widget
Since: ArcGIS Maps SDK for JavaScript 4.19Widget since 4.2, when added at 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.ParametersReturnsType 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 });