I am working on OCR reader application. below is my java code. My question is how to start another method if one is completed?

Question

1. When the user captures the image, the device will automatically read aloud the text. for that i have implemented texttospeech method but when this activity stop i want to start another task. how will it can be done?
2. After reading the captured text, I want to implement another text-to-speech method how can i do this?

package com.example.software2.ocrhy;

import static android.Manifest.permission.CAMERA;

import android.Manifest;
import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.speech.RecognizerIntent;
import android.speech.tts.TextToSpeech;
import android.util.SparseArray;
import android.view.KeyEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;

import com.google.android.gms.common.api.Status;
import com.google.android.gms.vision.CameraSource;
import com.google.android.gms.vision.Detector;
import com.google.android.gms.vision.text.TextBlock;
import com.google.android.gms.vision.text.TextRecognizer;

import org.jetbrains.annotations.Nullable;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Locale;


public class MainActivity2 extends AppCompatActivity {
    private static final int REQUEST_SPEECH = 101;
    private static final int REQ_CODE_SPEECH_INPUT = 100;
    Button buttonCamera;
    private Button button;
    private TextView mVoiceInputTv;
    private TextView textView;
    private SurfaceView surfaceView;
    private CameraSource cameraSource;
    private TextRecognizer textRecognizer;
    private static TextToSpeech textToSpeech;
    private String stringResult = null;


    @RequiresApi(api = Build.VERSION_CODES.N)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        mVoiceInputTv = (TextView) findViewById(R.id.textView);
        textView = (TextView) findViewById(R.id.textView);
        getWindow().getDecorView().setBackgroundColor(Color.WHITE);
        ActivityCompat.requestPermissions(this, new String[]{CAMERA}, PackageManager.PERMISSION_GRANTED);

        textToSpeech = new TextToSpeech(this, new TextToSpeech.OnInitListener() {
            @Override
            public void onInit(int status) {
                if (status != TextToSpeech.ERROR) {
                    textToSpeech.setLanguage(Locale.CANADA);
                    textToSpeech.setSpeechRate(1f);
                    Toast.makeText(MainActivity2.this, "tap on the screen and say yes for read and no for return to the main menu", Toast.LENGTH_SHORT).show();
                    textToSpeech.speak("tap on the screen and say yes for read and no for return to the main menu", TextToSpeech.QUEUE_ADD, null);
                }
            }
        });
    }

    private void textRecognizer() {
        Toast.makeText(MainActivity2.this, "Tap on the screen and listen ", Toast.LENGTH_SHORT).show();
        textToSpeech.speak(" Tap on the screen take a picture of any text with your device and listen", TextToSpeech.QUEUE_FLUSH, null);
        textRecognizer = new TextRecognizer.Builder(getApplicationContext()).build();
        cameraSource = new CameraSource.Builder(getApplicationContext(), textRecognizer)
                .setRequestedPreviewSize(1280, 1024)
                .setAutoFocusEnabled(true)
                .build();
        surfaceView = findViewById(R.id.surfaceView);

        Context context = this;
        surfaceView.getHolder().addCallback(new SurfaceHolder.Callback() {
            @Override
            public void surfaceCreated(SurfaceHolder holder) {
                try {
                    if (ActivityCompat.checkSelfPermission(context, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
                        return;
                    }
                    cameraSource.start(surfaceView.getHolder());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            @Override
            public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
            }

            @Override
            public void surfaceDestroyed(SurfaceHolder holder) {
                cameraSource.stop();
            }
        });
    }

    private void capture() {
        textRecognizer.setProcessor(new Detector.Processor<TextBlock>() {
            @Override
            public void release() {
            }

            @Override
            public void receiveDetections(Detector.Detections<TextBlock> detections) {
                SparseArray<TextBlock> sparseArray = detections.getDetectedItems();
                StringBuilder stringBuilder = new StringBuilder();

                for (int i = 0; i < sparseArray.size(); ++i) {
                    TextBlock textBlock = sparseArray.valueAt(i);
                    if (textBlock != null && textBlock.getValue() != null) {
                        stringBuilder.append(textBlock.getValue() + " ");
                    }
                }

                final String stringText = stringBuilder.toString();

                Handler handler = new Handler(Looper.getMainLooper());
                handler.post(new Runnable() {
                    @Override
                    public void run() {
                        stringResult = stringText;
                        resultObtained();
                    }
                });
            }
        });
    }

    private void resultObtained() {
        setContentView(R.layout.activity_main2);
        textView = findViewById(R.id.textView);
        textView.setText(stringResult);
        textToSpeech.speak(stringResult, TextToSpeech.QUEUE_FLUSH, null, null);
        

        textView.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            startVoiceInput();
        }
    });
}


    private void startVoiceInput() {
        Intent intent = new Intent(RecognizerIntent.ACTION_RECOGNIZE_SPEECH);
        intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE_MODEL, RecognizerIntent.LANGUAGE_MODEL_FREE_FORM);
        intent.putExtra(RecognizerIntent.EXTRA_LANGUAGE, Locale.getDefault());
        intent.putExtra(RecognizerIntent.EXTRA_PROMPT, "Hello, How can I help you?");
        try {
            startActivityForResult(intent, REQ_CODE_SPEECH_INPUT);
        } catch (ActivityNotFoundException a) {

        }
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (requestCode) {
            case REQ_CODE_SPEECH_INPUT: {
                if (resultCode == RESULT_OK && null != data) {
                    ArrayList<String> result = data.getStringArrayListExtra(RecognizerIntent.EXTRA_RESULTS);
                    mVoiceInputTv.setText(result.get(0));
                }
                if (mVoiceInputTv.getText().toString().contentEquals("time and date")) {
                    Intent intent = new Intent(getApplicationContext(), MainActivity4.class);
                    startActivity(intent);
                }
                if (mVoiceInputTv.getText().toString().contentEquals("battery")) {
                    Intent intent = new Intent(getApplicationContext(), MainActivity6.class);
                    startActivity(intent);
                    mVoiceInputTv.setText(null);
                }
                if (mVoiceInputTv.getText().toString().contentEquals("location")) {
                    Intent intent = new Intent(getApplicationContext(), MainActivity8.class);
                    startActivity(intent);
                    mVoiceInputTv.setText(null);
                }
                if (mVoiceInputTv.getText().toString().contentEquals("weather")) {
                    Intent intent = new Intent(getApplicationContext(), MainActivity5.class);
                    startActivity(intent);
                    mVoiceInputTv.setText(null);
                } else {
                    textToSpeech.speak( "Do not understand just tap on the screen Say again", TextToSpeech.QUEUE_FLUSH, null);
                }
                if (mVoiceInputTv.getText().toString().contentEquals("calculator")) {
                    Intent intent = new Intent(getApplicationContext(), MainActivity3.class);
                    startActivity(intent);
                    mVoiceInputTv.setText(null);
                }
                else if(mVoiceInputTv.getText().toString().contentEquals("exit")) {
                    finish();
                }
                else {
                    textToSpeech.speak("Do not understand just tap on the screen Say again", TextToSpeech.QUEUE_FLUSH, null);
                }

                if (mVoiceInputTv.getText().toString().contentEquals("yes")) {
                    setContentView(R.layout.surface);
                    surfaceView = findViewById(R.id.surfaceView);
                    surfaceView.setOnClickListener((View v) -> {
                        capture();
                    });
                    textRecognizer();
                    mVoiceInputTv.setText(null);
                } else if (mVoiceInputTv.getText().toString().contentEquals("no")) {
                    Intent intent = new Intent(getApplicationContext(), MainActivity.class);
                    startActivity(intent);
                }
                break;

            }
        }

    }
    public boolean onKeyDown(int keyCode, @Nullable KeyEvent event) {
        if(keyCode == KeyEvent.KEYCODE_VOLUME_UP){
            textToSpeech.speak("You are in main menu. just swipe right and say what you want", TextToSpeech.QUEUE_FLUSH, null);
            Intent intent = new Intent(getApplicationContext(), MainActivity.class);
            startActivity(intent);
            final Handler handler = new Handler(Looper.getMainLooper());
            handler.postDelayed(new Runnable() {
                @Override
                public void run() {
                    textToSpeech.speak("you are in main menu. just swipe right and say what you want", TextToSpeech.QUEUE_FLUSH, null);

                }
            },1000);

        }
        return true;
    }
        public void buttonStart(View view) {

            startVoiceInput();
        }
    public void onPause() {
        if (textToSpeech != null) {
            textToSpeech.stop();
        }
        super.onPause();
    }

}

Answer 1

You have to call startVoiceInput() again.

You are setting this call for an onClick() handler on a TextView already.