Ultisnips: autocompletion of (). Make snippet not expand again

Question

I want to make a Ultisnips snippet for auto completion of (), "", {}, etc. I have Tab as my expand and jump forward key. My snippet is:

snippet ( "parenthesis" iA
(${1:${VISUAL}})$0
endsnippet

And it works great most of the times, but I sometimes have to write parenthesis or quotes without any text.

In that case I type ( and then it expands as (), but when I want to go out of the parenthesis by pressing Tab, it expands the snippet again and I'm left with ()).

I have no idea how to change this based on the documentation; is there an option to configure this behavior? Or how should I configure this snippet?

Answer 1

I got it to work:

    global !p
    def mycontext(char):
        x = vim.current.window.buffer
        y = vim.current.window.cursor[0]
        z = vim.current.window.cursor[1]
        try:
            return x[y-1][z-1] + x[y-1][z] != char 
        except:
            return True 
    endglobal
    
    context "mycontext('()')"
    snippet ( "parenthesis" iA
    (${1:${VISUAL}})$0
    endsnippet