KeyEvent's key attribute and modifier keys in WX backend

[GlazLafee]

I just notice that "key" attribute of KeyEvent has changed when modifier keys are activated (e.g. previously "up", now "ctrl+up"). I have updated my code but i report that "key" attribute is sometimes wrong. When Alt or Ctrl are pressed, "key" attribute is respectively "alt" and "control" but, when Alt or Ctrl are released, "key" is "alt+alt" and "ctrl+control". I suggest to add a test before loop which prefixes "key" with modifier keys.

def _get_key(self, evt):

        keyval = evt.m_keyCode
        if keyval in self.keyvald:
            key = self.keyvald[keyval]
        elif keyval < 256:
            key = chr(keyval)
            # wx always returns an uppercase, so make it lowercase if the shift
            # key is not depressed (NOTE: this will not handle Caps Lock)
            if not evt.ShiftDown():
                key = key.lower()
        else:
            key = None

        # Adds a test to prevent this issue.
        if key not in ("alt", "control"):
            for meth, prefix in (
                                 [evt.AltDown, 'alt'],
                                 [evt.ControlDown, 'ctrl'], ):
                if meth():
                    key = '{0}+{1}'.format(prefix, key)

        return key

[pelson]

I'd agree this is a bug.

FWIW (and others seeing this) the documentation for the keys can be found here: http://matplotlib.org/api/backend_bases_api.html#matplotlib.backend_bases.KeyEvent. In essence, the fact that alt+control is a valid key combination is mentioned.

The only thing to watch out for is what happens when the two ctrl buttons are pressed - should the result be ctrl+control?

[tacaswell]

@YannGoudard Is this still an issue on master (I don't have wx on this machine to test)? There has been a bunch of work recently improving the modifier key handling of several of the backends.

[GlazLafee]

@tacaswell I have tested master and this bug no longer exists.

[tacaswell]

@YannGoudard Thanks!