Package com.google.gwt.geolocation.client

Class Geolocation

java.lang.Object

com.google.gwt.geolocation.client.Geolocation

public class Geolocation
extends Object

Implements the HTML5 Geolocation interface.

You can obtain a user's position by first calling Geolocation.getIfSupported()

Once you have a Geolocation, you can request the user's current position by calling getCurrentPosition(Callback) or watchPosition(Callback).

The first time an application requests the user's position, the browser will prompt the user for permission. If the user grants permission, the browser will locate the user and report it back to your application. If the user declines permission, the callback's Callback.onFailure(Object) method will be called with a PositionError with its code set to PositionError.PERMISSION_DENIED.

Experimental API: This API is still under development and is subject to change.

This may not be supported on all browsers.

See Also:

• W3C Geolocation API
• Dive Into HTML5 - Geolocation

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Geolocation.PositionOptions	Additional options for receiving the user's location.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Geolocation()	Should be instantiated by getIfSupported().

Method Summary

Modifier and Type	Method	Description
void	clearWatch(int watchId)	Stops watching the user's position.
void	getCurrentPosition(Callback<Position,PositionError> callback)	Calls the callback with the user's current position.
void	getCurrentPosition(Callback<Position,PositionError> callback, Geolocation.PositionOptions options)	Calls the callback with the user's current position, with additional options.
static Geolocation	getIfSupported()	Returns a Geolocation if the browser supports this feature, and null otherwise.
static boolean	isSupported()	Returns true if the browser supports geolocation.
int	watchPosition(Callback<Position,PositionError> callback)	Repeatedly calls the given callback with the user's position, as it changes.
int	watchPosition(Callback<Position,PositionError> callback, Geolocation.PositionOptions options)	Repeatedly calls the given callback with the user's position, as it changes, with additional options.

Methods inherited from class java.lang.Object

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

Constructor Details

Geolocation

protected Geolocation()

Should be instantiated by getIfSupported().

Method Details

getIfSupported

public static Geolocation getIfSupported()

Returns a Geolocation if the browser supports this feature, and null otherwise.

isSupported

public static boolean isSupported()

Returns true if the browser supports geolocation.

clearWatch

public void clearWatch(int watchId)

Stops watching the user's position.

Parameters:

watchId - the ID of a position watch as returned by a previous call to watchPosition(Callback).

getCurrentPosition

public void getCurrentPosition(Callback<Position,PositionError> callback)

Calls the callback with the user's current position.

getCurrentPosition

public void getCurrentPosition(Callback<Position,PositionError> callback,
 Geolocation.PositionOptions options)

Calls the callback with the user's current position, with additional options.

watchPosition

public int watchPosition(Callback<Position,PositionError> callback)

Repeatedly calls the given callback with the user's position, as it changes.

The frequency of these updates is entirely up to the browser. There is no guarantee that updates will be received at any set interval, but are instead designed to be sent when the user's position changes. This method should be used instead of polling the user's current position.

Returns:

the ID of this watch, which can be passed to clearWatch(int) to stop watching the user's position.

watchPosition

public int watchPosition(Callback<Position,PositionError> callback,
 Geolocation.PositionOptions options)

Repeatedly calls the given callback with the user's position, as it changes, with additional options.

The frequency of these updates is entirely up to the browser. There is no guarantee that updates will be received at any set interval, but are instead designed to be sent when the user's position changes. This method should be used instead of polling the user's current position.

If the browser does not support geolocation, this method will do nothing, and will return -1.

Returns:

the ID of this watch, which can be passed to clearWatch(int) to stop watching the user's position.