Package arez.dom

Class GeoPosition

java.lang.Object

arez.dom.GeoPosition

@ArezComponent(requireId=DISABLE,
               disposeNotifier=DISABLE)
public abstract class GeoPosition
extends Object

A component that exposes the current geo position as an observable property. This component relies on the underlying Geolocation API and it's usage is restricted in the same way as the underlying API (i.e. it is only available in secure contexts and it asks user permission before providing data.).

 EventDrivenValue<Window, Integer> innerWidth = EventDrivenValue.create( window, "resize", () -> window.innerWidth )
 

It is important that the code not add a listener to the underlying event source until there is an observer accessing the "value" observable defined by the EventDrivenValue class. The first observer that observes the observable will result in an event listener being added to the event source and this listener will not be removed until there is no observers left observing the value. This means that a component that is not being used has very little overhead.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	GeoPosition.Status

Method Summary

Modifier and Type	Method	Description
static GeoPosition	create()	Create the GeoPosition component.
String	getErrorMessage()	Return the error message reported by the geolocation API when position could not be loaded else null.
Position	getPosition()	Return an immutable representation of the current position.
int	getStatus()	Return the status indicating whether the position is available.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

create

@Nonnull public static GeoPosition create()

Create the GeoPosition component.

Returns:

the newly created GeoPosition component.

getPosition

@Memoize(depType=AREZ_OR_EXTERNAL)
@Nullable public Position getPosition()

Return an immutable representation of the current position. This will be null unless getStatus() has returned a GeoPosition.Status.POSITION_LOADED value.

Returns:

the current position as reported by the geolocation API.

getStatus

@Memoize(depType=AREZ_OR_EXTERNAL)
public int getStatus()

Return the status indicating whether the position is available. It will be one of the values provided by GeoPosition.Status.

Returns:

the status of the position data.

getErrorMessage

@Memoize(depType=AREZ_OR_EXTERNAL)
@Nullable public String getErrorMessage()

Return the error message reported by the geolocation API when position could not be loaded else null.

Returns:

the error message if any.