android flash alert2,Turning on/off flash with Android camera2 API not

I'm creating an Android app with a custom camera and I'm switching to the new camera2 API. I have a button allowing to turn ON and OFF the flash when the back camera is on (without stopping the camera, like any classic camera app).

When I tap the flash icon, nothing happens and this is what the logcat returns:

D/ViewRootImpl: ViewPostImeInputStage processPointer 0

D/ViewRootImpl: ViewPostImeInputStage processPointer 1

I don't know why it's not working. Here is the code:

I have a RecordVideoActivity using a RecordVideoFragment. Here is the fragment's XML part that contains the flash button code:

android:id="@+id/button_flash"

android:src="@drawable/ic_flash_off"

android:layout_alignParentLeft="true"

style="@style/actions_icons_camera"

android:onClick="actionFlash"/>

And the Java code:

ImageButton flashButton;

private boolean hasFlash;

private boolean isFlashOn = false;

With in the onViewCreated:

@Override

public void onViewCreated(final View view, Bundle savedInstanceState) {

...

[some code]

...

// Flash on/off button

flashButton = (ImageButton) view.findViewById(R.id.button_flash);

// Listener for Flash on/off button

flashButton.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View v) {

actionFlash();

}

});

And here is the actionFlash() function definition:

private void actionFlash() {

/* First check if device is supporting flashlight or not */

hasFlash = getActivity().getApplicationContext().getPackageManager()

.hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);

if (!hasFlash) {

// device doesn't support flash

// Show alert message and close the application

AlertDialog alert = new AlertDialog.Builder(this.getActivity())

.create();

alert.setMessage("Sorry, your device doesn't support flash light!");

alert.setButton(DialogInterface.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int which) {

dialog.dismiss();

}

});

alert.show();

return;

}

else { // the device support flash

CameraManager mCameraManager = (CameraManager) getActivity().getSystemService(Context.CAMERA_SERVICE);

try {

String mCameraId = mCameraManager.getCameraIdList()[0];

if (mCameraId.equals("1")) { // currently on back camera

if (!isFlashOn) { // if flash light was OFF

// Turn ON flash light

try {

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

mCameraManager.setTorchMode(mCameraId, true);

}

} catch (Exception e) {

e.printStackTrace();

}

// Change isFlashOn boolean value

isFlashOn = true;

// Change button icon

flashButton.setImageResource(R.drawable.ic_flash_off);

} else { // if flash light was ON

// Turn OFF flash light

try {

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {

mCameraManager.setTorchMode(mCameraId, false);

}

} catch (Exception e) {

e.printStackTrace();

}

// Change isFlashOn boolean value

isFlashOn = false;

// Change button icon

flashButton.setImageResource(R.drawable.ic_flash_on);

}

}

} catch (CameraAccessException e) {

Toast.makeText(getActivity(), "Cannot access the camera.", Toast.LENGTH_SHORT).show();

getActivity().finish();

}

}

}

Any idea what could be wrong?

(I already looked at this question but it doesn't address my problem)

Thank you very much for your help. This is driving me crazy.