MainActivity

package com.example.rafaelrp.melo_birthday;

import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    ImageView imgView;

    private SpeechToText stt;
    public static Context context;
    private boolean firstTime = true;
    private static TextView subtitle;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        subtitle = findViewById(R.id.textView);

        imgView = findViewById(R.id.imageView);
        imgView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                stt.callBackgroundListener();
            }
        });

        context = getApplicationContext();
        if(isFirstTime())
            setSST();
    }

    public static Context getContext() {
        return context;
    }

    public boolean isFirstTime() {
        return firstTime;
    }

    public void setFirstTime(boolean firstTime) {
        this.firstTime = firstTime;
    }

    public void setSST(){
        stt = new SpeechToText(this);
        setFirstTime(false);
    }

    public static void setsubtitle(String txt){
        subtitle.setText(txt);
    }
}