How to turn on the Android Flashlight

Question

Update

Check out my answer

Original

I'm trying to turn on the camera flashlight on the LG Revolution within my program. I use the torch mode method which works on most phones but not on LG phone. Does anyone know how to get it to work on LG's or specifically the Revolution?

Here's my manifest:

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

Here's my current code:

public Camera camera = Camera.open();
    public Camera.Parameters Flash = camera.getParameters();

With my on create:

            Flash.setFlashMode("torch");
            Parameters p = camera.getParameters();
            camera.setParameters(Flash);
            camera.startPreview();

I've seen people use an auto focus but i don't know if that would work.

Aglitter

So does no one know how to do this yet? – Aglitter

I've tried every method I could find, so far no luck...Does LG publish documentation on their specific Android implementation? – Satiated

Not that I've seen and they've never responded to the ticket I set up through their website – Aglitter

No I have not Pedro. And I don't think I can as I have no lg hardware. Hopefully someday someone will post it on this thread... – Aglitter

Answer 1

I thought I would update this with some bullet prof code that works on almost all 4.0+ devices.

public void turnOn() {
    camera = Camera.open();
    try {
        Parameters parameters = camera.getParameters();
        parameters.setFlashMode(getFlashOnParameter());
        camera.setParameters(parameters);

        camera.setPreviewTexture(new SurfaceTexture(0));

        camera.startPreview();
        camera.autoFocus(this);
    } catch (Exception e) {
        // We are expecting this to happen on devices that don't support autofocus.
    }
}

private String getFlashOnParameter() {
    List<String> flashModes = camera.getParameters().getSupportedFlashModes();

    if (flashModes.contains(FLASH_MODE_TORCH)) {
        return FLASH_MODE_TORCH;
    } else if (flashModes.contains(FLASH_MODE_ON)) {
        return FLASH_MODE_ON;
    } else if (flashModes.contains(FLASH_MODE_AUTO)) {
        return FLASH_MODE_AUTO;
    }
    throw new RuntimeException();
}

The real key is setting that fake SurfaceTexture so that the preview will actually start. Turning it off is very easy as well

public void turnOff() {
        try {
            camera.stopPreview();
            camera.release();
            camera = null;
        } catch (Exception e) {
            // This will happen if the camera fails to turn on.
        }
}

Aglitter

Would you please share the getFlashOnParameter() method as well? – Sven

Oops on that! My bad, I'll get that up with 0-100 business days. – Aglitter

Updated answer to contain this method. – Aglitter

I expect a +1 Flyview! – Aglitter

hehe I had already +1 :) Does the FLASH_MODE_AUTO ever work for any devices? I had built similar logic myself but only put in TORCH and ON. – Sven

I think that it used to work for Samsung but I cannot remember. – Aglitter

Works on my Umidigi A3 Pro, which required the line: camera.setPreviewTexture(new SurfaceTexture(0)); – Barytes

Answer 2

It seems like the developer of the Tiny Flashlight + LED app on the Android Market figured out how to make the flashlight work on LG Revolution.

Maybe you can contact him and ask? You can also check the permissions he is using in his app to try to make your app work!

Good luck!

Idem

No response from Tiny Flasher :( Still don't know this one yet. – Aglitter

Answer 3

Test this :

if(camera == null){

camera = Camera.open();
parameters = camera.getParameters();

List<String> flashModes = parameters.getSupportedFlashModes();

    if(flashModes != null && flashModes.contains(Parameters.FLASH_MODE_TORCH)){

        //appareil supportant le mode torch
        parameters.setFlashMode(Parameters.FLASH_MODE_TORCH);
        camera.setParameters(parameters);
    } else if (flashModes != null && flashModes.contains(Parameters.FLASH_MODE_ON)){

        //spécial samsung
        parameters.setFlashMode(Parameters.FLASH_MODE_ON);
        camera.setParameters(parameters);
        camera.startPreview();
        camera.autoFocus(new AutoFocusCallback() {
            public void onAutoFocus(boolean success, Camera camera) { }
        });
    } else {
        parameters.setFlashMode(Parameters.FLASH_MODE_OFF);
        camera.setParameters(parameters);
    }  

        parameters.setFlashMode( Parameters.FLASH_MODE_OFF );
        camera.setParameters(parameters);
        camera.release();
        camera = null;

    } catch (RuntimeException e) {}

}//if

Refute

I'll test it out sometime this next week. – Aglitter

This seemed to not work for me. I am adding the autofocus and I'll see if that works when I get a chance to us it on an LG phone. Though I had to do camera.autoFocus(new Camera.AutoFocusCallback() { public void onAutoFocus(boolean success, Camera camera) { } – Aglitter

So with the autoFocus the Spectrum™ by LG worked. I'm not sure it needed it though or if it's just a different phone, I'll find out and update. – Aglitter

@ViToBrothers I second that :/ I have tried every possible variation on the Galaxy SII - no luck ... My code works on the Sony Xperia S though. – Grievance

Answer 4

This worked well for LG Nexus:

camera = Camera.open();
camera.setPreviewTexture(new SurfaceTexture(0));
camera.setParameters(p);
camera.startPreview();

Disconsolate

Answer 5

/*TESTED LG G4 */
public void flashOnOff(){
    List<String> flashModes = parameter001.getSupportedFlashModes();

    if(flashModes != null &&    flashModes.contains(Parameters.FLASH_MODE_TORCH)){

        //appareil supportant le mode torch
        parameter001.setFlashMode(Parameters.FLASH_MODE_TORCH);
        mCamera.setParameters(parameter001);
    } else if (flashModes != null && flashModes.contains(Parameters.FLASH_MODE_ON)){

        //spécial samsung
        parameter001.setFlashMode(Parameters.FLASH_MODE_ON);
        mCamera.setParameters(parameter001);

        mCamera.autoFocus(new AutoFocusCallback() {
            public void onAutoFocus(boolean success, Camera camera) { }
        });
    } else {
        parameter001.setFlashMode(Parameters.FLASH_MODE_OFF);
        mCamera.setParameters(parameter001);
    } 
    if (!isFlashOn) {
        if (mCamera == null || parameter001 == null) {
            return;
        }

        parameter001 = mCamera.getParameters();
        parameter001.setFlashMode(Parameters.FLASH_MODE_TORCH);
        mCamera.setParameters(parameter001);
        try {
            mCamera.setPreviewTexture(new SurfaceTexture(0));
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        mCamera.startPreview();
        isFlashOn = true;

        // changing button/switch image

    }else if (isFlashOn) {
        if (mCamera == null || parameter001 == null) {
            return;
        }

        parameter001 = mCamera.getParameters();
        parameter001.setFlashMode(Parameters.FLASH_MODE_OFF);
        mCamera.setParameters(parameter001);
        mCamera.stopPreview();
        isFlashOn = false;


    }
}

Sokil

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