Thanks for your review.

1. It is hard to sort an array if the array itself does not also contain the data that it should be sorted by.
2. Yes I could do that, but that wouldn't improve readability (I could only replace the innermost loop which doesn't make a big difference in readability), but it would also mean an unnecessary drop in performance based on the data mentioned here in the second answer.
3. You are right. I was thinking about making a new class "Button", but that has some complications so I decided to keep it as it is for now(until the next update).