I found a nice code for QRcode/Barcode recognition - it is working fine BUT ! It is working non-stop. Detected code is displayed in barcodeText but the method/proces/camera (initialiseDetectorsAndSources()) is still working. I tried a few things to stop it and found that cameraSource.release() is somewhat working : camera stops but I'm not sure if the detector process is still running somewhere in background ?. Then I added a button to start the initialiseDetectorsAndSources() method again => to start the process of QRCode recognition - but it is not starting. The camera is not working.
How can I stop the process or recognition of a code after founding the code ?
How can I start again the process to read next qrcode ?
Can I move the method initialiseDetectorsAndSources() to a new class, outside the mainactivity ? ... this method starts after the program is launched - I would like to start the process of code recognition after ...for example I press a button.
Thanks for help :)
here is my MainActivity.java :
package net.ginekolog.qrtest01;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;
import android.Manifest;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.media.AudioManager;
import android.media.ToneGenerator;
import android.os.Bundle;
import android.util.SparseArray;
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 com.google.android.gms.vision.CameraSource;
import com.google.android.gms.vision.Detector;
import com.google.android.gms.vision.barcode.Barcode;
import com.google.android.gms.vision.barcode.BarcodeDetector;
import java.io.IOException;
import java.util.Objects;
public class MainActivity extends AppCompatActivity {
private SurfaceView surfaceView;
private BarcodeDetector barcodeDetector;
private CameraSource cameraSource;
private static final int REQUEST_CAMERA_PERMISSION = 201;
private ToneGenerator toneGen1;
private TextView barcodeText;
private String barcodeData;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
toneGen1 = new ToneGenerator(AudioManager.STREAM_MUSIC, 100);
surfaceView = findViewById(R.id.surface_view);
barcodeText = findViewById(R.id.barcode_text);
Button button = (Button) findViewById(R.id.startQRscanButton);
button.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Do something in response to button click
initialiseDetectorsAndSources();
Toast.makeText(getApplicationContext(), "button clicked", Toast.LENGTH_LONG).show();
}
});
// initialiseDetectorsAndSources();
Toast.makeText(getApplicationContext(), "onCreate : end", Toast.LENGTH_LONG).show();
}
private void initialiseDetectorsAndSources() {
Toast.makeText(getApplicationContext(), "iD&S : Barcode scanner started", Toast.LENGTH_SHORT).show();
barcodeDetector = new BarcodeDetector.Builder(this)
.setBarcodeFormats(Barcode.ALL_FORMATS)
.build();
cameraSource = new CameraSource.Builder(this, barcodeDetector)
.setRequestedPreviewSize(1024, 768)//1920x1080
.setAutoFocusEnabled(true)//you should add this feature
//.setRequestedFps(10)//default is 30
.build();
surfaceView.getHolder().addCallback(new SurfaceHolder.Callback() {
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
cameraSource.start(surfaceView.getHolder());
} else {
ActivityCompat.requestPermissions(MainActivity.this, new
String[]{Manifest.permission.CAMERA}, REQUEST_CAMERA_PERMISSION);
}
} 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();
}
});
barcodeDetector.setProcessor(new Detector.Processor<Barcode>() {
@Override
public void release() {
Toast.makeText(getApplicationContext(), "release : To prevent memory leaks barcode scanner has been stopped", Toast.LENGTH_SHORT).show();
}
@Override
public void receiveDetections(Detector.Detections<Barcode> detections) {
final SparseArray<Barcode> barcodes = detections.getDetectedItems();
if (barcodes.size() != 0) {
barcodeText.post(new Runnable() {
@Override
public void run() {
if (barcodes.valueAt(0).email != null)
{
barcodeText.removeCallbacks(null);
barcodeData = barcodes.valueAt(0).email + " - email ";
// barcodeData = barcodes.valueAt(0).email.address;
// barcodeData = barcodes.valueAt(0).rawValue;
barcodeText.setText(barcodeData);
toneGen1.startTone(ToneGenerator.TONE_CDMA_PIP, 1150);
// stop kamera
cameraSource.release();
}
else
{
barcodeData = barcodes.valueAt(0).displayValue + " display value ";
barcodeText.setText(barcodeData);
toneGen1.startTone(ToneGenerator.TONE_CDMA_PIP, 1150);
// stop ... how ?
// cameraSource.stop();
// barcodes.clear();
cameraSource.release();
// barcodeDetector.release();
// surfaceView.releasePointerCapture();
// surfaceView.clearFocus();
// release();
}
}
});
}
}
});
};
@Override
protected void onPause() {
super.onPause();
Objects.requireNonNull(getSupportActionBar()).show();
cameraSource.release();
}
@Override
protected void onResume() {
super.onResume();
Objects.requireNonNull(getSupportActionBar()).show();
initialiseDetectorsAndSources();
}
}
