Develop Reference

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

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?
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();
}
}

just use the same mode on text to speech ADD and it will play when the first one is done, ADD = ADD, FLUSH = reset
textToSpeech.speak("this will play when first is done",
TextToSpeech.QUEUE_ADD, null);

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

App keeps crashing cause of broadcastreceiver

Can anyone help me debug which part of my code is the reason why it keeps crashing? I've been trying to figure out which part is wrong, I got the code online and applied it on my own but I had troubles on this part where it keeps saying app is
I created different functions to figure out which part is wrong, thank you.
in my logcat it says:
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.String.intern()' on a null object reference
Mainactivty
import androidx.appcompat.app.AppCompatActivity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.TextView;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
public class MainActivity extends AppCompatActivity {
private TextView tv_time;
private TextView tv_amount;
private ImageView iv_status_01;
private ImageView iv_status_02;
private ImageView iv_status_03;
private ImageView iv_status_04;
private ImageView iv_status_05;
private ImageView iv_status_06;
private ImageView iv_complete;
private Intent serviceInent = null;
public static String status1;
public static String status2;
public static String status3;
public static String status4;
public static String status5;
public static String status6;
private IntentFilter intentFilter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
intentFilter = new IntentFilter();
intentFilter.addAction(status1);
intentFilter.addAction(status2);
intentFilter.addAction(status3);
intentFilter.addAction(status4);
intentFilter.addAction(status5);
intentFilter.addAction(status6);
init();
}
private void init(){
tv_amount = findViewById(R.id.tv_amount);
tv_time = findViewById(R.id.tv_time);
Date date = new Date();
Locale philippineLocale = new Locale.Builder().setLanguage("en").setRegion("PH").build();
tv_time.setText(getDate(date, philippineLocale));
tv_amount.setText("Total Amount :\n500.00");
serviceInent = new Intent(this, DeliveryService.class);
startService(new Intent(this, DeliveryService.class));
}
private String getDate(Date date, Locale locale) {
DateFormat formatter = new SimpleDateFormat("EEEE \nMMMM dd, yyyy", locale);
return formatter.format(date);
}
#Override
public void onResume() {
super.onResume();
registerReceiver(mReceiver, intentFilter);
}
private BroadcastReceiver mReceiver = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
if (intent.getAction().equals(status1)) {
iv_status_01.setImageResource(R.drawable.box_check);
}
else if (intent.getAction().equals(status2)) {
iv_status_02.setImageResource(R.drawable.box_check);
}
else if (intent.getAction().equals(status3)) {
iv_status_03.setImageResource(R.drawable.box_check);
}
else if (intent.getAction().equals(status4)) {
iv_status_04.setImageResource(R.drawable.box_check);
}
else if (intent.getAction().equals(status5)) {
iv_status_05.setImageResource(R.drawable.box_check);
}
else if (intent.getAction().equals(status5)) {
iv_status_06.setImageResource(R.drawable.box_check);
}
}
};
#Override
protected void onPause() {
unregisterReceiver(mReceiver);
super.onPause();
}
}
Deliveryservice:
import android.annotation.TargetApi;
import android.app.Service;
import android.content.Intent;
import android.os.Build;
import android.os.IBinder;
import android.util.Log;
public class DeliveryService extends Service {
private String LOG_TAG = null;
#Override
public void onCreate() {
super.onCreate();
LOG_TAG = this.getClass().getSimpleName();
Log.i(LOG_TAG, "In onCreate");
}
#Override
public int onStartCommand(Intent intent, int flags, int startId) {
Log.i(LOG_TAG, "In onStartCommand");
new Thread(new Runnable() {
public void run() {
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
Intent broadcastIntent = new Intent();
broadcastIntent.setAction(MainActivity.status1);
sendBroadcast(broadcastIntent);
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
broadcastIntent.setAction(MainActivity.status2);
sendBroadcast(broadcastIntent);
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
broadcastIntent.setAction(MainActivity.status3);
sendBroadcast(broadcastIntent);
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
broadcastIntent.setAction(MainActivity.status4);
sendBroadcast(broadcastIntent);
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
broadcastIntent.setAction(MainActivity.status5);
sendBroadcast(broadcastIntent);
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
e.printStackTrace();
}
broadcastIntent.setAction(MainActivity.status6);
sendBroadcast(broadcastIntent);
}
}).start();
return START_REDELIVER_INTENT;
}
#Override
public IBinder onBind(Intent intent) {
Log.i(LOG_TAG, "In onBind");
return null;
}
#TargetApi(Build.VERSION_CODES.ICE_CREAM_SANDWICH)
#Override
public void onTaskRemoved(Intent rootIntent) {
super.onTaskRemoved(rootIntent);
Log.i(LOG_TAG, "In onTaskRemoved");
}
public void onDestroy() {
super.onDestroy();
Log.i(LOG_TAG, "In onDestroy");
}
}
thank you.

You should initialize strings used as Action (like status1); otherwise, NullProinterException will be thrown.

App crashed moving one activity to another activity after some seconds splash screen

package com.example.firstclasswithahmad;
import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import java.security.PublicKey;
import javax.crypto.spec.DHPublicKeySpec;
public class SplashScreen extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash_screen);
Thread td= new Thread(){
public void run(){
try {
Thread.sleep(3000);
} catch (Exception e){
e.printStackTrace();
} finally {
Intent i=new Intent(SplashScreen.this, MainActivity.class);
startActivity(i);
}
}
};
td.start();
}
}

Try to create the intent inside the onPostCreate() method. Like this:
#Override
protected void onPostCreate(#Nullable Bundle savedInstanceState) {
super.onPostCreate(savedInstanceState);
Thread td = new Thread() {
public void run() {
try {
Thread.sleep(3000);
} catch (Exception e) {
e.printStackTrace();
} finally {
Intent i = new Intent(SplashScreen.this, MainActivity.class);
startActivity(i);
}
}
};
td.start();
}

Intent in condition doesn't work

I have tried searching for this topic but i didn't find anything that would help me, so here I am asking this.
I am a beginner so I don't understand a lot of terms and if you answer my question please try to use simple language so I could understand.
I have a condition in that the elements at same position of two lists are compared and if they aren't equal than it jumps to another activity:
if (randomColors.get(i) != userColors.get(i)) {
Intent i = new Intent( GameActivity.this, GameOverActivity.class);
startActivity(i);
}
and it displays an error in debugging that I cannot solve:
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.gabie212.simonsays/com.gabie212.simonsays.GameOverActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.view.View.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
Please help me, I am a beginner and I don't know what's wrong with my code because I have done exactly as they taught us in class...
Here is the complete code
I know its not the best but its a work in proggress
package com.gabie212.simonsays;
import android.content.Context;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
import java.util.ArrayList;
public class GameActivity extends AppCompatActivity implements
View.OnClickListener {
private int i = 0;
private Thread t = new Thread();
private Button greenButton;
private Button redButton;
private Button blueButton;
private Button yellowButton;
private Button startButton;
private ArrayList<Integer> randomColors = new ArrayList<Integer>();
private ArrayList<Integer> userColors = new ArrayList<Integer>();
private GameManger gm;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
gm = new GameManger(this);
setContentView(R.layout.activity_game);
greenButton = (Button) findViewById(R.id.btnGreen);
redButton = (Button) findViewById(R.id.btnRed);
blueButton = (Button) findViewById(R.id.btnBlue);
yellowButton = (Button) findViewById(R.id.btnYellow);
startButton = (Button) findViewById(R.id.btnStart);
startButton.setOnClickListener(this);
greenButton.setOnClickListener(this);
redButton.setOnClickListener(this);
blueButton.setOnClickListener(this);
yellowButton.setOnClickListener(this);
}
#Override
public void onClick(View v) {
int num;
num= gm.getColor(4);
randomColors.add(num);
android.os.Handler handler = new android.os.Handler();
//TODO if the start button is pressed multiple times simultaneously it starts the lightup loop multiple times simultaneously
if (v.getId() == startButton.getId()) {
for (i = 0; i < randomColors.size(); i++) //light up loop
{
switch (randomColors.get(i)) {
case 1:
greenButton.setBackgroundResource(R.drawable.greenlightup);
handler.postDelayed(new Runnable()
{
#Override
public void run() {
// TODO Auto-generated method stub
greenButton.setBackgroundResource(R.drawable.green);
}
}, 2000);
break;
case 2:
redButton.setBackgroundResource(R.drawable.redlightup);
handler.postDelayed(new Runnable()
{
#Override
public void run() {
// TODO Auto-generated method stub
redButton.setBackgroundResource(R.drawable.red);
}
}, 2000);
break;
case 3:
blueButton.setBackgroundResource(R.drawable.bluelightup);
handler.postDelayed(new Runnable()
{
#Override
public void run() {
// TODO Auto-generated method stub
blueButton.setBackgroundResource(R.drawable.blue);
}
}, 2000);
break;
case 4:
yellowButton.setBackgroundResource(R.drawable.yellowlightup);
handler.postDelayed(new Runnable()
{
#Override
public void run() {
// TODO Auto-generated method stub
yellowButton.setBackgroundResource(R.drawable.yellow);
}
}, 2000);
break;
}
handler.postDelayed(new Runnable()
{
public void run() {
}
}, 2000);
}
for(i=0;i<randomColors.size();i++)
{
if(v.getId()==greenButton.getId())
{
userColors.add(1);
}
else
{
if(v.getId()==redButton.getId()){
userColors.add(2);
}
else
{
if(v.getId()==blueButton.getId())
{
userColors.add(3);
}
else
{
userColors.add(4);
}
}
}
}
for(i=0;i<randomColors.size();i++)
{
if(randomColors.get(i)!=userColors.get(i))
{
Intent i = new Intent( GameActivity.this, GameOverActivity.class);
startActivity(i);
}
}
}
}
}
by the its not a simple null pointer exception, at least i don't think so because there is nothing here to be null, there is only a simple intent in an if statement
here's the code for the game over activity
package com.gabie212.simonsays;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Button;
import android.view.View;
public class GameOverActivity extends AppCompatActivity implements View.OnClickListener {
private Button againButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_game_over);
againButton = (Button) findViewById(R.id.btnStart);
againButton.setOnClickListener(this);
}
#Override
public void onClick(View view) {
Intent in = new Intent(GameOverActivity.this, GameActivity.class);
startActivity(in);
}
}
Thanks in advance.

In your GameOverActivity, on this line:
againButton = (Button) findViewById(R.id.btnStart);
Your againButton is null as you are referencing btnStart from your main activity layout (activity_game.xml). This can't be found because your GameOverActivity is using activity_game_over.xml for its layout:
setContentView(R.layout.activity_game_over);
Any views need to be defined within the activity_game_over.xml file for them to be used by the activity. You need to reference the ID of the button as defined in layout/activity_game_over.xml
againButton = (Button) findViewById(R.id.btnAgain); // Or whatver you've named it
As for your specific question as to why the Intent is not working, the Intent itself is working fine, it's just that GameOverActivity cannot start up properly due to the above issue, and therefore your app crashes.

How to Stop a Loop at the Press of a Button

I want the onClick method not only to create a new activity to the new page, but also to trigger the end of the loop, so that if someone clicks the background of the splash screen, the new screen doesn't reload after the loop stops.
Here is my code,
package clouds.clouds;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class splash extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.splash);
Thread logotimer = new Thread() {
#Override
public void run(){
try{
int logotimer = 0;
while(logotimer <5000) {
sleep(100);
logotimer = logotimer +100;
}
startActivity(new Intent("clouds.clouds.SPLASH"));
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
finish();
}
}
};
logotimer.start();
}
public void onClickz(View v){}
public void speed2 (View v){
startActivity(new Intent("clouds.clouds.BUTTONZ"));
}
}
Any suggestions?

Call logotimer.interrupt() in your onClick() method. This should cause an InterruptedException in your thread which you should handle by doing nothing (or whatever else you want to do when you interrupt your thread)

Add a volatile boolean variable to your class (call it cancelled). Set it to true when the button is clicked, and check for cancelled == false in your while condition.
public class splash extends Activity {
volatile bool cancelled = false;
...
protected void onCancel(...)
{
cancelled = true;
...
while(!cancelled && logotimer <5000) {
...

boolean exit = false;
int logotimer = 0;
while(logotimer <5000 && exit != false) {
sleep(100);
logotimer = logotimer +100;
// value = ???
if(logotimer == value) {
exit = true;
}
}

package clouds.clouds;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
public class splash extends Activity {
Thread logotimer;
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.splash);
logotimer = new Thread();
Thread logotimer = new Thread() {
#Override
public void run(){
try{
int logotimer = 0;
while(logotimer <5000) {
sleep(100);
logotimer = logotimer +100;
}
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
finally{
finish();
}
startActivity(new Intent("clouds.clouds.SPLASH"));
}
};
logotimer.start();
}
public void onClickz (View v){}
public void speed2 (View v){
logotimer.interrupt();
startActivity(new Intent("clouds.clouds.BUTTONZ"));
}
}