Operation Options: Enumeration blocks for App Inventor

App Inventor is a web application for building Android apps, which includes a block-based coding editor. The editor includes many blocks which accept enums as inputs. Currently these inputs are filled by assigning a constant number, which is not very readable nor localizable.

This project seeks to replace those constants with enumeration dropdowns. These dropdown-blocks will be defined via Java annotations, so that they can also be added by App Inventor extensions. They will then be added as shadow blocks to the blocks in the toolbox. In addition, other means of accessing the non-shadow versions of these blocks may be added.