Anki 2.1 Add-on Enhancement

Hello, I am currently learning Chinese and am looking to have an existing python-based add-on for a flashcard program modified for my needs. The add on is this: [login to view URL] The description of what it does and its open source code on github is all in the above link. Currently the add-on only works by reading an entire deck of flashcards and giving the user the option of adding pinyin notation to all cards at once given a certain selection criteria. What I would like to enhance is having the add-on add a button to the individual card editor which when hit, would allow the ability to create pinyin for the hanzi (Chinese character) field one card at a time.