@Override
public void onResume()
{
    super.onResume();

    if (!HasCameraPermission())
    {
        RequestCameraPermission();

        return;
    }
}

@Override
public void onRequestPermissionsResult(int _RequestCode, String[] _Permissions, int[] _Results)
{
    if (!HasCameraPermission())
    {
        Toast.makeText(this, "Camera permission is needed to run this application", Toast.LENGTH_LONG).show();

        if (!ShouldShowRequestPermissionRationale())
        {
            // Permission denied checking "Do not ask again".
            LaunchPermissionSettings();
        }

        finish();
    }
}

public boolean HasCameraPermission()
{
    return this.checkSelfPermission(Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED;
}

public void RequestCameraPermission()
{
    this.requestPermissions(new String[] {Manifest.permission.CAMERA}, 0);
}

public boolean ShouldShowRequestPermissionRationale()
{
    return this.shouldShowRequestPermissionRationale(Manifest.permission.CAMERA);
}

public void LaunchPermissionSettings()
{
    Intent intent = new Intent();
    intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
    intent.setData(Uri.fromParts("package", this.getPackageName(), null));

    this.startActivity(intent);
}