try with scannerActivity override

app/src/main/java/net/foucry/pilldroid/DrugListActivity.java

@@ -286,7 +286,7 @@ public class DrugListActivity extends AppCompatActivity {
         options.addExtra(Intents.Scan.SCAN_TYPE, Intents.Scan.MIXED_SCAN);
         options.addExtra(Intents.Scan.SCAN_TYPE, Intents.Scan.INVERTED_SCAN);
         //barcodeLauncher.launch(options);
-        Intent intent = new Intent(getApplicationContext(), CustomScannerActivity.class);
+        Intent intent = new Intent(getApplicationContext(), ScannerActivity.class);
         Bundle bundle = new Bundle();
         intent.putExtras(bundle);
         mBarcodeScannerLauncher.launch(intent);

app/src/main/java/net/foucry/pilldroid/ScanContract.java

@@ -0,0 +1,144 @@
+package net.foucry.pilldroid;
+
+import android.content.Context;
+import android.content.Intent;
+
+import androidx.activity.result.contract.ActivityResultContract;
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+public class ScanContract extends ActivityResultContract<ScanOptions, ScanIntentResult> {
+
+    private static final String TAG = ScanContract.class.getName();
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+      super.onCreate(savedInstanceState);
+      
+      findViewById(R.id.keyboard_button).setOnClickListener(this::onkeyboard);
+      findViewById(R.id.cancel_button).setOnClickListener(this::onCancel);
+      findViewById(R.id.switch_flashlight).setOnClickListener(this::switchFlashLight);
+      viewfinderView = findViewById(R.id.zxing_viewfinder_view);
+
+      barcodeScannerView = findViewById(R.id.zxing_barcode_scanner);
+
+      capture = new CaptureManager(this, barcodeScannerView);
+      Intent captureIntent = createIntent(this, options);
+      Bundle captureIntentBundle = new Bundle();
+
+      captureIntentBundle.putBoolean(Intents.Scan.BEEP_ENABLED, true);
+      captureIntent.putExtras(captureIntentBundle);
+      capture.initializeFromIntent(captureIntent, savedInstanceState);
+
+      changeMaskColor(null);
+      changeLaserVisibility(true);
+
+      barcodeScannerView.decodeSingle(new BarcodeCallback() {
+        @Override
+        public void barcodeResult(BarcodeResult result) {
+          Intent scanResult = new Intent();
+          scanResult.putExtra("Barcode Content", result.getText());
+          scanResult.putExtra("Barcode Forma name", result.getBarcodeFormat().name());
+          scanResult.putExtra("returnCode", capture.captureIntentBundle.getInt("returnCode"));
+          scanResult.putExtra("resultCode", 1);
+          ScannerContract.this.setResult(RESULT_OK, scanResult);
+          
+          Log.d(TAG, "scanResult ==" + scanResult.toString());
+          finish();
+        }
+      });
+    }
+    
+    @NonNull
+    @Override
+    public Intent createIntent(@NonNull Context context, ScanOptions input) {
+        return input.createScanIntent(context);
+    }
+
+    @Override
+    public ScanIntentResult parseResult(int resultCode, @Nullable Intent intent) {
+        return ScanIntentResult.parseActivityResult(resultCode, intent);
+    }
+
+        @Override
+    protected void onResume() {
+        super.onResume();
+        capture.onResume();
+    }
+
+    @Override
+    protected void onPause() {
+        super.onPause();
+        capture.onPause();
+    }
+
+    @Override
+    protected void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+        capture.onSaveInstanceState(outState);
+    }
+
+    @Override
+    public boolean onKeyDown(int keyCode, KeyEvent event) {
+        return barcodeScannerView.onKeyDown(keyCode, event) || super.onKeyDown(keyCode, event);
+    }
+    
+    /**
+     * Check if the device's camera has a Flashlight.
+     *
+     * @return true if there is Flashlight, otherwise false.
+     */
+    private boolean hasFlash() {
+        return getApplicationContext().getPackageManager()
+                .hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);
+    }
+
+    public void switchFlashlight(View view) {
+        Log.d(TAG, "Switch torch");
+        if (switchFlashlightButton.isActivated()) {
+            barcodeScannerView.setTorchOff();
+        } else {
+            barcodeScannerView.setTorchOn();
+        }
+    }
+
+    public void changeMaskColor(View view) {
+        Random rnd = new Random();
+        int color = Color.argb(100, rnd.nextInt(256), rnd.nextInt(256), rnd.nextInt(256));
+        viewfinderView.setMaskColor(color);
+    }
+  
+    public void changeLaserVisibility(boolean visible) {
+        viewfinderView.setLaserVisibility(visible);
+    }
+
+    public void onTorchOn() {
+        Log.d(TAG, "TorchON");
+        switchFlashlightButton.setActivated(true);
+    }
+
+    public void onTorchOff() {
+        Log.d(TAG, "TorchOFF");
+        switchFlashlightButton.setActivated(false);
+    }
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
+        capture.onRequestPermissionsResult(requestCode, permissions, grantResults);
+    }
+
+    public void onKeyboard(View view) {
+        Log.d(TAG, "onkeyboard");
+        Intent resultIntent = new Intent();
+        resultIntent.putExtra("returnCode",3);
+        CustomScannerActivity.this.setResult(RESULT_OK, resultIntent);
+        finish();
+    }
+
+    public void onCancel(View view) {
+        Log.d(TAG, "onCancel");
+        Intent resultIntent = new Intent();
+        resultIntent.putExtra("returnCode", 2);
+        CustomScannerActivity.this.setResult(RESULT_OK, resultIntent);
+        finish();
+    }
+}