Event Listeners

When you register an EventListener, you can receive events for the preparation, start, completion, stopping, volume change, and errors of a speech synthesis request.

Callback	Description
`onReady()`	Called when the `speak()` request is ready to be processed.
`onStart()`	Called when speech playback starts.
`onUpdatedRms(rms)`	Called when the RMS (Root Mean Square) value is updated during playback.
`onDone()`	Called when the requested speech playback finishes successfully.
`onStop()`	Called when ongoing playback is stopped.
`onError(errorType)`	Called when an error occurs during processing.

Kotlin
Java

private val eventListener = object : EventListener {
    override fun onReady() = Unit
    override fun onStart() = Unit
    override fun onUpdatedRms(rms: Double) = Unit
    override fun onDone() = Unit
    override fun onStop() = Unit

    override fun onError(errorType: ErrorType) {
        // Handle errors.
    }
}

textToSpeech.addEventListener(eventListener)

private final EventListener eventListener = new EventListener() {
    @Override public void onReady() {}
    @Override public void onStart() {}
    @Override public void onUpdatedRms(double rms) {}
    @Override public void onDone() {}
    @Override public void onStop() {}

    @Override
    public void onError(ErrorType errorType) {
        // Handle errors.
    }
};

textToSpeech.addEventListener(eventListener);

Remove the same instance used for registration when the listener is no longer needed or before releasing the SDK.

textToSpeech.removeEventListener(eventListener)

For handling errors by type, refer to Error code.