How to turn on front flash light programmatically

Question

I want to turn on front flash light (not with camera preview) programmatically in Android. I googled for it but the help i found referred me to this page

Does anyone have any links or sample code?

Answer 1

For this problem you should:

1. Check whether the flashlight is available or not?

2. If so then Turn Off/On

3. If not then you can do whatever, according to your app needs.

For Checking availability of flash in the device:

You can use the following:

 context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);

which will return true if a flash is available, false if not.

See:
http://developer.android.com/reference/android/content/pm/PackageManager.html for more information.

For turning on/off flashlight:

I googled out and got this about android.permission.FLASHLIGHT. Android manifests' permission looks promising:

 <!-- Allows access to the flashlight -->
 <permission android:name="android.permission.FLASHLIGHT"
             android:permissionGroup="android.permission-group.HARDWARE_CONTROLS"
             android:protectionLevel="normal"
             android:label="@string/permlab_flashlight"
             android:description="@string/permdesc_flashlight" />

Then make use of Camera and set Camera.Parameters. The main parameter used here is FLASH_MODE_TORCH.

eg.

Code Snippet to turn on camera flashlight.

Camera cam = Camera.open();     
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
cam.setParameters(p);
cam.startPreview();

Code snippet to turn off camera led light.

  cam.stopPreview();
  cam.release();

I just found a project that uses this permission. Check quick-settings' src code. here http://code.google.com/p/quick-settings/ (Note: This link is now broken)

For Flashlight directly look http://code.google.com/p/quick-settings/source/browse/trunk/quick-settings/#quick-settings/src/com/bwx/bequick/flashlight (Note: This link is now broken)

Update6 You could also try to add a SurfaceView as described in this answer LED flashlight on Galaxy Nexus controllable by what API? This seems to be a solution that works on many phones.

Update 5 Major Update

I have found an alternative Link (for the broken links above): http://www.java2s.com/Open-Source/Android/Tools/quick-settings/com.bwx.bequick.flashlight.htm You can now use this link. [Update: 14/9/2012 This link is now broken]

Update 1

Another OpenSource Code : http://code.google.com/p/torch/source/browse/

Update 2

Example showing how to enable the LED on a Motorola Droid: http://code.google.com/p/droidled/

Another Open Source Code :

http://code.google.com/p/covedesigndev/
http://code.google.com/p/search-light/

Update 3 (Widget for turning on/off camera led)

If you want to develop a widget that turns on/off your camera led, then you must refer my answer Widget for turning on/off camera flashlight in android..

Update 4

If you want to set the intensity of light emerging from camera LED you can refer Can I change the LED intensity of an Android device? full post. Note that only rooted HTC devices support this feature.

** Issues:**

There are also some problems while turning On/Off flashlight. eg. for the devices not having FLASH_MODE_TORCH or even if it has, then flashlight does not turn ON etc.

Typically Samsung creates a lot of problems.

You can refer to problems in the given below list:

Use camera flashlight in Android

Turn ON/OFF Camera LED/flash light in Samsung Galaxy Ace 2.2.1 & Galaxy Tab

Answer 2

Android Lollipop introduced camera2 API and deprecated the previous camera API. However, using the deprecated API to turn on the flash still works and is much simpler than using the new API.

It seems that the new API is intended for use in dedicated full featured camera apps and that its architects didn't really consider simpler use cases such as turning on the flashlight. To do that now, one has to get a CameraManager, create a CaptureSession with a dummy Surface, and finally create and start a CaptureRequest. Exception handling, resource cleanup and long callbacks included!

To see how to turn the flashlight on Lollipop and newer, take a look at the FlashlightController in the AOSP project (try to find the newest as older use APIs that have been modified). Don't forget to set the needed permissions.

---

Android Marshmallow finally introduced a simple way to turn on the flash with setTorchMode.

Answer 3

You can also use the following code to turn off the flash.

Camera.Parameters params = mCamera.getParameters()
p.setFlashMode(Parameters.FLASH_MODE_OFF);
mCamera.setParameters(params);

Answer 4

From my experience, if your application is designed to work in both portrait and landscape orientation, you need to declare the variable cam as static. Otherwise, onDestroy(), which is called on switching orientation, destroys it but doesn't release Camera so it's not possible to reopen it again.

package com.example.flashlight;

import android.hardware.Camera;
import android.hardware.Camera.Parameters;
import android.os.Bundle;
import android.app.Activity;
import android.content.pm.PackageManager;
import android.view.Menu;
import android.view.View;
import android.widget.Toast;

public class MainActivity extends Activity {

public static Camera cam = null;// has to be static, otherwise onDestroy() destroys it

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

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.activity_main, menu);
    return true;
}

public void flashLightOn(View view) {

    try {
        if (getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA_FLASH)) {
            cam = Camera.open();
            Parameters p = cam.getParameters();
            p.setFlashMode(Parameters.FLASH_MODE_TORCH);
            cam.setParameters(p);
            cam.startPreview();
        }
    } catch (Exception e) {
        e.printStackTrace();
        Toast.makeText(getBaseContext(), "Exception flashLightOn()",
                Toast.LENGTH_SHORT).show();
    }
}

public void flashLightOff(View view) {
    try {
        if (getPackageManager().hasSystemFeature(
                PackageManager.FEATURE_CAMERA_FLASH)) {
            cam.stopPreview();
            cam.release();
            cam = null;
        }
    } catch (Exception e) {
        e.printStackTrace();
        Toast.makeText(getBaseContext(), "Exception flashLightOff",
                Toast.LENGTH_SHORT).show();
    }
}
}

to manifest I had to put this line

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

from http://developer.android.com/reference/android/hardware/Camera.html

suggested lines above wasn't working for me.

Answer 5

I Got AutoFlash light with below simple Three Steps.

• I just added Camera and Flash Permission in Manifest.xml file

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

<uses-permission android:name="android.permission.FLASHLIGHT"/>
<uses-feature android:name="android.hardware.camera.flash" android:required="false" />

• In your Camera Code do this way.

  //Open Camera
  Camera  mCamera = Camera.open(); 
  
  //Get Camera Params for customisation
  Camera.Parameters parameters = mCamera.getParameters();
  
  //Check Whether device supports AutoFlash, If you YES then set AutoFlash
  List<String> flashModes = parameters.getSupportedFlashModes();
  if (flashModes.contains(android.hardware.Camera.Parameters.FLASH_MODE_AUTO))
  {
       parameters.setFlashMode(Parameters.FLASH_MODE_AUTO);
  }
  mCamera.setParameters(parameters);
  mCamera.startPreview();
  

• Build + Run —> Now Go to Dim light area and Snap photo, you should get auto flash light if device supports.

Answer 6

There's different ways to access Camera Flash in different Android versions. Few APIs stopped working in Lollipop and then it got changed again in Marshmallow. To overcome this, I have created a simple library that I have been using in few of my projects and it's giving good results. It's still incomplete, but you can try to check the code and find the missing pieces. Here's the link - NoobCameraFlash.

If you just want to integrate in your code, you can use gradle for that. Here's the instructions (Taken directly from the Readme) -

Step 1. Add the JitPack repository to your build file. Add it in your root build.gradle at the end of repositories:

allprojects {
        repositories {
            ...
            maven { url "https://jitpack.io" }
        }
}

Step 2. Add the dependency

dependencies {
        compile 'com.github.Abhi347:NoobCameraFlash:0.0.1'
  }

Usage

Initialize the NoobCameraManager singleton.

NoobCameraManager.getInstance().init(this);

You can optionally set the Log Level for debug logging. Logging uses LumberJack library. The default LogLevel is LogLevel.None

NoobCameraManager.getInstance().init(this, LogLevel.Verbose);

After that you just need to call the singleton to turn on or off the camera flash.

NoobCameraManager.getInstance().turnOnFlash();
NoobCameraManager.getInstance().turnOffFlash();

You have to take care of the runtime permissions to access Camera yourself, before initializing the NoobCameraManager. In version 0.1.2 or earlier we used to provide support for permissions directly from the library, but due to dependency on the Activity object, we have to remove it.

It's easy to toggle Flash too

if(NoobCameraManager.getInstance().isFlashOn()){
    NoobCameraManager.getInstance().turnOffFlash();
}else{
    NoobCameraManager.getInstance().turnOnFlash();
}