Turn ON/OFF flashlight in zxing fragment lib

Question

I have implemented Zxing barcode scanning library in my application. I have used following library: https://code.google.com/p/barcodefraglibv2/ I want to turn ON/OFF the flash light on click of a button when scanning but I am not able to do this. Library has exposed one function for the same but it is not working.

Code used is: fragment = (BarcodeFragment)getSupportFragmentManager().findFragmentById(R.id.sample); fragment.getCameraManager().setTorch(true);

Provide me any refrence code by which I can turn ON/OFF flashlight.

Answer 1

You should go through the sample app in zxing-android-embedded library, there you can find CustomScannerActivity class which shows how to switch ON and OFF flash light below is the link:

https://github.com/journeyapps/zxing-android-embedded/blob/master/sample/src/main/java/example/zxing/CustomScannerActivity.java

Code sample from above link:

public class CustomScannerActivity extends Activity implements
    DecoratedBarcodeView.TorchListener {

private CaptureManager capture;
private DecoratedBarcodeView barcodeScannerView;
private Button switchFlashlightButton;

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

    barcodeScannerView = (DecoratedBarcodeView)findViewById(R.id.zxing_barcode_scanner);
    barcodeScannerView.setTorchListener(this);

    switchFlashlightButton = (Button)findViewById(R.id.switch_flashlight);

    // if the device does not have flashlight in its camera,
    // then remove the switch flashlight button...
    if (!hasFlash()) {
        switchFlashlightButton.setVisibility(View.GONE);
    }

    capture = new CaptureManager(this, barcodeScannerView);
    capture.initializeFromIntent(getIntent(), savedInstanceState);
    capture.decode();
}

@Override
protected void onResume() {
    super.onResume();
    capture.onResume();
}

@Override
protected void onPause() {
    super.onPause();
    capture.onPause();
}

@Override
protected void onDestroy() {
    super.onDestroy();
    capture.onDestroy();
}

@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) {
    if (getString(R.string.turn_on_flashlight).equals(switchFlashlightButton.getText())) {
        barcodeScannerView.setTorchOn();
    } else {
        barcodeScannerView.setTorchOff();
    }
}

@Override
public void onTorchOn() {
    switchFlashlightButton.setText(R.string.turn_off_flashlight);
}

@Override
public void onTorchOff() {
    switchFlashlightButton.setText(R.string.turn_on_flashlight);
} 
}

Answer 2

You can use this:

public void flashON(View v) {
   mScannerView.setFlash(true);
}

public void flashOFF(View v){
   mScannerView.setFlash(false);
}

Where flashON and flashOFF are 2 ImageButtons. This is xml:

 <me.dm7.barcodescanner.zxing.ZXingScannerView
  android:id="@+id/zxscan"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content">
 
 </me.dm7.barcodescanner.zxing.ZXingScannerView>

 <ImageButton
   android:id="@+id/FlashON"
   android:onClick="flashON"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_alignEnd="@+id/FlashOFF"
   android:layout_alignParentTop="true"
   android:layout_alignRight="@+id/FlashOFF"
   android:layout_marginEnd="60dp"
   android:layout_marginRight="60dp"
   android:src="@drawable/flashon" />

 <ImageButton
   android:id="@+id/FlashOFF"
   android:onClick="flashOFF"
   android:layout_width="50dp"
   android:layout_height="50dp"
   android:layout_alignParentEnd="true"
   android:layout_alignParentRight="true"
   android:layout_below="@+id/NumeEchip"
   android:layout_marginEnd="13dp"
   android:layout_marginRight="13dp"
   android:src="@drawable/flashoff" />

Answer 3

You need to add these the following permission and feature to your Manifest in order to control the flash.

<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />

Here's a sample code -

import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.ToggleButton;

/**
 * @author Prabu 
 * July 30 2013
 * @version 1.0
 * 
 */
public class FlashlightActivity extends Activity {
 private Camera camera;
 private ToggleButton button;
 private final Context context = this;
 /**
  * @see android.app.Activity#onStop()
  */
 @Override
 protected void onStop() {
  super.onStop();
  if (camera != null) {
   camera.release();
  }
 }

 /**
  * @see android.app.Activity#onCreate(android.os.Bundle)
  */
 @Override
 public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.flashlight);
  button = (ToggleButton) findViewById(R.id.togglebutton);

  final PackageManager pm = context.getPackageManager();
  if(!isCameraSupported(pm)){
   AlertDialog alertDialog = new AlertDialog.Builder(context).create();
   alertDialog.setTitle("No Camera");
      alertDialog.setMessage("The device's doesn't support camera.");
      alertDialog.setButton(RESULT_OK, "OK", new DialogInterface.OnClickListener() {
          public void onClick(final DialogInterface dialog, final int which) { 
           Log.e("err", "The device's doesn't support camera.");
          }
       });
   alertDialog.show();
  }
  camera = Camera.open();
 }
 public void onToggleClicked(View view) {
  PackageManager pm=context.getPackageManager();
  final Parameters p = camera.getParameters();
  if(isFlashSupported(pm)){
   boolean on = ((ToggleButton) view).isChecked();
   if (on) {
    Log.i("info", "torch is turn on!");
    p.setFlashMode(Parameters.FLASH_MODE_TORCH);
    camera.setParameters(p);
    camera.startPreview();
   } else {
    Log.i("info", "torch is turn off!");
    p.setFlashMode(Parameters.FLASH_MODE_OFF);
    camera.setParameters(p);
    camera.stopPreview();
   }
  }else{
   button.setChecked(false);
   AlertDialog alertDialog = new AlertDialog.Builder(context).create();
   alertDialog.setTitle("No Camera Flash");
      alertDialog.setMessage("The device's camera doesn't support flash.");
      alertDialog.setButton(RESULT_OK, "OK", new DialogInterface.OnClickListener() {
          public void onClick(final DialogInterface dialog, final int which) { 
           Log.e("err", "The device's camera doesn't support flash.");
          }
       });
   alertDialog.show();
  }
 }
 /**
  * @param packageManager
  * @return true <b>if the device support camera flash</b><br/>
  * false <b>if the device doesn't support camera flash</b>
  */
 private boolean isFlashSupported(PackageManager packageManager){ 
  // if device support camera flash?
  if (packageManager.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH)) {
   return true;
  } 
  return false;
 }

 /**
  * @param packageManager
  * @return true <b>if the device support camera</b><br/>
  * false <b>if the device doesn't support camera</b>
  */
 private boolean isCameraSupported(PackageManager packageManager){
  // if device support camera?
  if (packageManager.hasSystemFeature(PackageManager.FEATURE_CAMERA)) {
   return true;
  } 
  return false;
 }
}

For full source - > Visit Here

Answer 4

open CameraManager activity from zxing source code and paste follwing code in startPreview(). before camera.startPreview()

 Camera.Parameters p;
 p = camera.getParameters();
 p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
 camera.setParameters(p);