androidandroid-camera

How to turn on front flash light programmatically in Android?


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?


Solution

  • For 2021, with CameraX, it is now dead easy: https://stackoverflow.com/a/66585201/294884


    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