shortcuts

undo : alt+u, option+u (option 可能是alt键)
redo : alt+e, option+e

Search class name: ctrl+shift+T
Go into declaration: F3
Go back: c+q
Find Impl: F4

Search class name(emacs mode): c+x c+f
Go into declaration: c+alt+g
Go into declaration: undefined

undo: ctrl+z
redo: ctrl+shift+z