TextToSpeech api wrapper

TalkUtils.java

package com.accenture.acncodechallengeandroid.utils;

import android.content.Context;
import android.os.Build;
import android.speech.tts.TextToSpeech;
import android.speech.tts.UtteranceProgressListener;

import java.lang.ref.WeakReference;

/**
 * Text to Speech Utilities Class
 * Wrapper of TextToSpeech api
 */
public class TalkUtils extends UtteranceProgressListener implements TextToSpeech.OnInitListener {
    private static TalkUtils instance;

    private WeakReference<Context> context;
    private String text;
    private TextToSpeech engine = null;
    private boolean isRunning = false;
    private int count = 0;

    private TalkUtils(Context context) {
        this.context = new WeakReference<>(context);
    }

    /**
     * Shared Instance
     * @param context Application context so it won't leaks
     * @return TextUtils instance
     */
    public static TalkUtils getInstance(Context context) {
        if (instance == null) {
            instance = new TalkUtils(context);
        }
        return instance;
    }

    public void talk(String text) {
        this.text = text;

        if (ensureTalkEngineReady()) startTalk();
    }

    private boolean ensureTalkEngineReady() {
        if (engine != null && isRunning) return true;
        Context context = this.context.get();
        if (context == null) return false;

        count = 0;
        engine = new TextToSpeech(context, this);
        engine.setOnUtteranceProgressListener(this);

        isRunning = true;
        return false;
    }

    private void startTalk() {
        count++;

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            engine.speak(text, TextToSpeech.QUEUE_ADD, null, "");
        } else {
            engine.speak(text, TextToSpeech.QUEUE_ADD, null);
        }
        text = null;
    }

    private void clear() {
        count--;

        if (count > 0) return;
        engine.shutdown();
        engine = null;
        isRunning = false;
    }

    @Override
    public void onInit(int status) {
        if (status == TextToSpeech.SUCCESS) startTalk();
    }

    @Override
    public void onStart(String utteranceId) {
    }

    @Override
    public void onDone(String utteranceId) {
        clear();
    }

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