Class WebSpeechTtsSynthesizer

A TtsSynthesizer implementation using the Web Speech API for synthesizing text.

You can optionally provide a callback function that will be called when the synthesizer creates a new utterance, but before the utterance is sent to the speechSynthesis engine. This happens after all the properties on the utterance have been set to their default values. The callback allows you to modify the utterance, such as setting the voice or any other attribute you'd like to change.

When changing the voice of an utterance, it is important to also change the language of the utterance. Otherwise, the voice attribute may be ignored in some browsers. Example:

new WebSpeechTtsSynthesizer(utterance => {
     utterance.voice = myVoice;
     utterance.lang = myVoice.lang
})
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Add the utterance to the queue of utterances to speak.

The implementation must stop any current playing utterance and set itself in paused state. It should then clear the queue of utterances to speak.

Destroys this instance. The synthesizer should clear the utterance queue and set itself in paused state. The reference to any context passed with init() is released.

Called before any other method to register the context instance used for various callbacks.

Will be called by the SyncMediaPlayer when it should pause playback.

Resume the playback of the current active utterance if any exists, otherwise the next utterance from the utterance queue. The implementation must use context.onUtteranceEnd() when each utterance has finished speaking.

The implementation should also call context.onBoundary(charOffset) to indicate which part of the utterance is currently being spoken to allow the media player to get a more accurate timeline position for things like automatically turning pages and resuming playback and for highlighting.

Sets if playback should be muted. When called with false, the synthesizer should unmute and use the playback volume last set by setVolume.

Will be called by the SyncMediaPlayer when its playbackRate has been changed.

Will be called by the SyncMediaPlayer when its volume has been changed.