@EActivity(R.layout.activity_main)
@RuntimePermissions
public class MainActivity extends AppCompatActivity {
    @Click(R.id.permissionButton)
    protected void askForPermission() {
        showCamera();
    }
    @NeedsPermission(Manifest.permission.CAMERA)
    protected void showCamera() {
        Toast.makeText(this, "Permission for camera granted", Toast.LENGTH_SHORT).show();
    }
    @OnPermissionDenied(Manifest.permission.CAMERA)
    protected void onPermissionDeniedCamera() {
        Toast.makeText(this, "@OnPermissionDenied for camera", Toast.LENGTH_SHORT).show();
    }
    
    @OnShowRationale(Manifest.permission.CAMERA)
    protected void showRationaleForCamera(PermissionRequest request) {
        Toast.makeText(this, "OnShowRationale for camera", Toast.LENGTH_SHORT).show();
        request.proceed();
    }
    @OnNeverAskAgain(Manifest.permission.CAMERA)
    protected void showNeverAskForCamera() {
        Toast.makeText(this, "OnNeverAskAgain for camera", Toast.LENGTH_SHORT).show();
    }
}