MessageListener

AI-generated Key Takeaways

• MessageListener is an abstract class used for receiving subscribed messages, providing callbacks when messages are found or lost.

• It offers methods to handle changes in Bluetooth Low Energy (BLE) signal strength and estimated distance for nearby messages.

• onFound is called when a message is first detected, while onLost is triggered when a message is no longer detectable.

• Callbacks related to BLE signal and distance changes are primarily designed for BLE beacon messages and might have limited functionality for other message types.

• Some callbacks are not supported when subscribing with a PendingIntent instead of a MessageListener.

public abstract class MessageListener extends Object

A listener for receiving subscribed messages. These callbacks will be delivered when messages are found or lost.

Public Constructor Summary

MessageListener()

Public Method Summary

void	onBleSignalChanged(Message message, BleSignal bleSignal) Called when the Bluetooth Low Energy (BLE) signal associated with a message changes.
void	onDistanceChanged(Message message, Distance distance) Called when Nearby's estimate of the distance to a message changes.
void	onFound(Message message) Called when messages are found.
void	onLost(Message message) Called when a message is no longer detectable nearby.

Inherited Method Summary

From class java.lang.Object

Object	clone()
boolean	equals(Object arg0)
void	finalize()
final Class<?>	getClass()
int	hashCode()
final void	notify()
final void	notifyAll()
String	toString()
final void	wait(long arg0, int arg1)
final void	wait(long arg0)
final void	wait()

Public Constructors

public MessageListener ()

Public Methods

public void onBleSignalChanged (Message message, BleSignal bleSignal)

Called when the Bluetooth Low Energy (BLE) signal associated with a message changes.

For example, this is called when we see the first BLE advertisement frame associated with a message; or when we see subsequent frames with different RSSI.

Note: This callback currently only works for BLE beacon messages.

Note: This callback is not supported by the version of Messages.subscribe(GoogleApiClient, PendingIntent) that takes a PendingIntent.

public void onDistanceChanged (Message message, Distance distance)

Called when Nearby's estimate of the distance to a message changes.

For example, this is called when we first gather enough information to make a distance estimate; or when the message remains nearby, but gets closer or further away.

Note: This callback currently only works for BLE beacon messages.

Note: This callback is not supported by the version of Messages.subscribe(GoogleApiClient, PendingIntent) that takes a PendingIntent.

Parameters

message	The message whose distance changed.
distance	The new distance estimate.

public void onFound (Message message)

Called when messages are found.

This method is called the first time the message is seen nearby. After a message has been lost (see onLost(Message)), it's eligible for onFound(Message) again.

Parameters

message	The found message.

public void onLost (Message message)

Called when a message is no longer detectable nearby.

Note: This callback currently works best for BLE beacon messages. For other messages, it may not be called in a timely fashion, or at all.

This method will not be called repeatedly (unless the message is found again between lost calls).

Parameters

message	The lost message.