XEP-0301: In-Band Real Time Text

In-Band Real Time Text

Initiating Real-Time Text

Real Time Text is transmitted in the context of a chat session, which is usually a one-to-one chat session, but can also be a multi-user chat.

So first you need to retrieve a Chat instance, e.g. as follows:

Chat chat = xmppClient.getManager(ChatManager.class).createChatSession(Jid.of("juliet@example.net"));

Next, create an OutboundRealTimeMessage object. It takes care of various aspects of real-time text, like:

  • calculating the diffs between text changes
  • the wait intervals for smoother user experience
  • submitting real-time text every 700ms (the recommended default)
  • as well as a ‘reset’ message every 10s.
RealTimeTextManager realTimeTextManager = xmppClient.getManager(RealTimeTextManager.class);
OutboundRealTimeMessage realTimeMessage = realTimeTextManager.createRealTimeMessage(chat);

Then whenever text changes, update the message. Here’s an example with a JavaFX TextArea:

textArea.textProperty().addListener((observable, oldValue, newValue) -> {
    realTimeMessage.update(newValue);
});

When done, it is important to commit the message (i.e. sending a backwards-compatible message with a <body/> element), which also shuts down executors, which were responsible for the transmission:

realTimeMessage.commit();

Most likely you now want to start a new real time message and clear the TextArea:

realTimeMessage = realTimeTextManager.createRealTimeMessage(chat);
textArea.clear();

Receiving Real-Time Messages

realTimeTextManager.addRealTimeMessageListener(e -> {
    InboundRealTimeMessage inboundRealTimeMessage = e.getRealTimeMessage();
    // Here route the message correctly to the sender's UI interface, using inboundRealTimeMessage.getFrom()
    inboundRealTimeMessage.addRealTimeTextChangeListener(t ->
        System.out.println(t.getText()));
});