public void onClickOk(@NonNull View view) {
        if (mListener == null) {
            return;
        }

        // Some invalid cases first
        /*if (MODE_NEW_FILE == mode && !isValidFileName(getNewFileName())) {
            mToast = Toast.makeText(getActivity(), github.tornaco.android.thanos.res.R.string.nnf_need_valid_filename,
                    Toast.LENGTH_SHORT);
            mToast.show();
            return;
        }*/
        if ((allowMultiple || mode == MODE_FILE) &&
                (mCheckedItems.isEmpty() || getFirstCheckedItem() == null)) {
            if (mToast == null) {
                mToast = Toast.makeText(getActivity(), github.tornaco.android.thanos.res.R.string.nnf_select_something_first,
                        Toast.LENGTH_SHORT);
            }
            mToast.show();
            return;
        }

        // New file allows only a single file
        if (mode == MODE_NEW_FILE) {
            final String filename = getNewFileName();
            final Uri result;
            if (filename.startsWith("/")) {
                // Return absolute paths directly
                result = toUri(getPath(filename));
            } else {
                // Append to current directory
                result = toUri(getPath(appendPath(getFullPath(mCurrentPath), filename)));
            }
            mListener.onFilePicked(result);
        } else if (allowMultiple) {
            mListener.onFilesPicked(toUri(mCheckedItems));
        } else if (mode == MODE_FILE) {
            //noinspection ConstantConditions
            mListener.onFilePicked(toUri(getFirstCheckedItem()));
        } else if (mode == MODE_DIR) {
            mListener.onFilePicked(toUri(mCurrentPath));
        } else {
            // single FILE OR DIR
            if (mCheckedItems.isEmpty()) {
                mListener.onFilePicked(toUri(mCurrentPath));
            } else {
                mListener.onFilePicked(toUri(getFirstCheckedItem()));
            }
        }
    }
Called when the ok-button is pressed.

@param view which was clicked. Not used in default implementation.
android/modules/module_filepicker/src/main/java/com/nononsenseapps/filepicker/AbstractFilePickerFragment.java