Android TextToSpeech Manager

TtsManager.java

import android.content.Context;
import android.speech.tts.TextToSpeech;
import android.speech.tts.UtteranceProgressListener;
import android.util.Log;

import java.util.HashMap;
import java.util.Locale;

/**
 * Created by Muzaffer Yılmaz on 24.04.2018.
 */
public class TtsManager implements TextToSpeech.OnInitListener {

    private final String[] mTexts;
    private final HashMap<String, String> mTtsMap;
    private final TextToSpeech mTts;
    private final TextSpeechProgressListener mProgressListener;
    private int mTextProgress = 0;
    private boolean mIsPlaying;

    public interface TextSpeechProgressListener {
        void onProgressChanged(int current, int max);
    }

    public TtsManager(Context context, String text, String splitRegex, @Nullable TextSpeechProgressListener listener) {
        mTexts = text.split(splitRegex);
        mProgressListener = listener;

        mTtsMap = new HashMap<>();
        mTtsMap.put(TextToSpeech.Engine.KEY_PARAM_UTTERANCE_ID, "TTS_ID");
        mTts = new TextToSpeech(context, this);

        mTts.setOnUtteranceProgressListener(new UtteranceProgressListener() {
            @Override
            public void onDone(String utteranceId) {
                if (!mIsPlaying || mTextProgress == mTexts.length) return;
                ++mTextProgress;
                updateProgress(mTextProgress, mTexts.length);
                speakWord();
            }

            @Override
            public void onStart(String utteranceId) {}

            @Override
            public void onError(String utteranceId) {}
        });
    }

    private void speakWord() {
        if (mTextProgress >= mTexts.length) return;
        mTts.speak(mTexts[mTextProgress], TextToSpeech.QUEUE_FLUSH, mTtsMap);
    }

    public void start() {
        mIsPlaying = true;
        speakWord();
    }

    public void pause() {
        mIsPlaying = false;
        mTts.stop();
        updateProgress(mTextProgress, mTexts.length);
    }

    public void stop() {
        mIsPlaying = false;
        mTts.stop();
        mTextProgress = 0;
        updateProgress(mTextProgress, mTexts.length);
    }

    private void updateProgress(int current, int max) {
        if (mProgressListener == null) return;
        mProgressListener.onProgressChanged(current, max);
    }

    public void changeProgress(int progress) {
        mTextProgress = progress;

        // If it's not playing, just change progress
        if (!mIsPlaying) return;

        // Otherwise start from given progress
        pause();
        start();
    }

    @Override
    public void onInit(int status) {
        if (status == TextToSpeech.SUCCESS) {
            int result = mTts.setLanguage(Locale.ROOT);
            if (result == TextToSpeech.LANG_MISSING_DATA || result == TextToSpeech.LANG_NOT_SUPPORTED) {
                Log.e("TTS", "This Language is not supported");
            }
        } else {
            Log.e("TTS", "Initialization Failed!");
        }
    }
}

Usage.java

TtsManager ttsManager = new TtsManager(context, description, "\\.", new TtsManager.TextSpeechProgressListener() {
    @Override
    public void onProgressChanged(int current, int max) {
        seekBar.setProgress(current);
        seekBar.setMax(max);
    }
});

seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        if (mTtsManager == null) return;
        mTtsManager.changeProgress(progress);
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {}

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {}
});

ttsManager.start();