inputPalette: going backwards

[cool-RR]

I made a UI for shoing plots that asks the user to make several choices using inputPalette. If the user regrets a choice and wants to go back to the previous prompt, is there any mechanism for that? Pressing Esc just aborts everything. I still want to have an option to abort everything.

[midichef]

The only bindings I see in inputPalette are for Tab, Shift+Tab, Enter and Space.

Maybe you could reserve a word like 'back' in your inputPalette choices and test for it as a return value?

choice_level = 0
while True:
    if (choice_level == 0):
        val1 = vd.inputPalette(...)
        if (val1 == `back`):
            break
        else:
            choice_level += 1
    if (choice_level == 1):
        val2 = vd.inputPalette(...)
        if (val2 == `back`):
	    choice_level -= 1
	else:
	    choice_level += 1
    if (choice_level == 2):
        val3 = vd.inputPalette(...)
        if val3 == 'back':
	    choice_level -= 1
	else:
	    break