How to encapsulate a startActivityForResult in a Java class and get the onActivityResult on the Activity that called the method

Question

Im using the next camera code in several activities and I would like to make a class that encapsulate the methods for using the camera in Android.

What I am trying to get is the Activity class be something like:

Public class Myfragment extends Fragment{
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v = inflater.inflate(R.layout.profile_fragment, container, false);
        mButtonProfilePhoto = v.findViewById(R.id.buttonProfilePhoto);

        mButtonProfilePhoto.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
        //Here I call the camera intent.
            Camera.dispatchTakePictureIntent(getActivity(), mPhotoFile);
            }
            });

    return v;
    }
        @Override
        public void onActivityResult(int requestCode, int resultCode, Intent data) {
              //handle the camera result
}

The Camera class looks something like this:

public class Camera{
public static void dispatchTakePictureIntent(Activity activity, File file) {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    // Ensure that there's a camera activity to handle the intent
    if (takePictureIntent.resolveActivity(activity.getPackageManager()) != null) {
        // Create the File where the photo should go
        file = null;
        try {
            file = Camera.createImageFile(activity);
        } catch (IOException ex) {
            // Error occurred while creating the File

        }
        // Continue only if the File was successfully created
        if (file  != null) {
            Uri photoURI = FileProvider.getUriForFile(activity,
                    "com.itcom202.weroom.fileprovider",
                    file );
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
            startActivityForResult( takePictureIntent, REQUEST_IMAGE_CAPTURE);


        }
    }
}
}

The issue that I have right now is that I never get a call back from onActivityResult from the fragment.

Hi Demi, welcome to S.O. Do you mean that you want to "catch" the result event inside the fragment itself, and not in its parent activity? — Barak, Apr 01 '19 at 22:01
Hi Barackos, I want to read the onactivityResult from a fragment, but the method of the camera will be implemented in a class (not an activity or fragment). — Demi Dimitrova, Apr 01 '19 at 22:05

score 1 · Accepted Answer · answered Apr 01 '19 at 22:13

OS has no support to send onActivityResult() to Fragment's. Support library, though, has a mechanism to do that, that registers the call to a special table in the AppCompatActivity. The trick here is that you have to use Fragment's own startActivityForResult(), not Activity's one.

So, your Camera class code should look like:

public class Camera{

    public static void dispatchTakePictureIntent(Activity activity, Fragment fragment, File file) {
        Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        // Ensure that there's a camera activity to handle the intent
        if (takePictureIntent.resolveActivity(activity.getPackageManager()) != null) {
            // Create the File where the photo should go
            file = null;
            try {
                file = Camera.createImageFile(activity);
            } catch (IOException ex) {
                // Error occurred while creating the File

            }
            // Continue only if the File was successfully created
            if (file  != null) {
                Uri photoURI = FileProvider.getUriForFile(activity,
                        "com.itcom202.weroom.fileprovider",
                        file );
                takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
                fragment.startActivityForResult(takePictureIntent, REQUEST_IMAGE_CAPTURE);
            }
        }
    }

}

Notice last line is using Fragment's startActivityForResult()

How to encapsulate a startActivityForResult in a Java class and get the onActivityResult on the Activity that called the method

1 Answers1