Key Input¶
This section deals with single or combined keypress input. For input involving typing longer strings, see Text Input.
See Processing Events for a discussion of the basics of dealing with input.
Jupyter notebook limitation: Key events are swallowed by the Jupyter notebook as part of the user interface and are not available to a VPython program.
What Keys are Down?¶
More than one key may be down at once. The keysdown() function provides a list of all keys that are currently down.
- mykeys = keysdown() # a list of keys
Keynames include:
single characters for alphanumeric keys, e.g. ‘b’
function keys ‘f1’ through ‘f10’
‘backspace’
‘caps lock’
‘tab’
‘shift’
‘ctrl’
‘alt’
‘pageup’
‘pagedown’
‘end’
‘home’
‘left’ (left arrow)
‘right’ (right arrow)
‘down’ (down arrow)
‘up’ (up arrow)
‘insert’
‘delete’
‘break’
Typing into a Label¶
The input() and winput() commands allow the processing of longer user input.
The test routine below lets the user type text one character at a time into a label:
prose = label() # initially blank text
def keyInput(evt):
s = evt.key
if len(s) == 1: # includes enter ('\n')
prose.text += s # append new character
elif ( s == 'delete' or s is 'backspace' ) and len(prose.text) > 0:
prose.text = prose.text[:-1] # erase letter
scene.bind('keydown', keyInput)
See also