Most of the subs are pretty modular and you should be able to delete the ones you don't need. Just keep Class_Globals, Initialize, AddButton, Button_Click, Button_Touch, GetText/SetText(If needed), GetViews/GetView(If Needed), Enabled(If Needed), GetCharSize, and SetNinePatchDrawable.
You'll just need the 2 button png files too then. Should make it easier to manage. Since I use a label to draw the button you already have click and touch events you can enhance for dragging.