class ActivityDataIOEditor implements ActivityDataIOEditorView.Presenter {

    @Override
    public void handleOkClick() {
        if (callback != null) {
            AssignmentData data = new AssignmentData(view.getInputAssignmentData(),
                                                     view.getOutputAssignmentData(),
                                                     dataTypes,
                                                     dataTypeDisplayNames);
            data.setVariableCountsString(hasInputVars,
                                         isSingleInputVar,
                                         hasOutputVars,
                                         isSingleOutputVar);
            String sData = marshallToJson(data);
            callback.getData(sData);
        }
        view.hideView();
    }

}