[Feature] Force Numpad to act like a Mac

[RedBearAK]

I'm in the process of making a feature I've been thinking about for a long time: Forced Numpad. (Edit: Renamed to "Mac Numpad").

On a Mac, the numeric keypad is always a numeric keypad, and the Numlock key is "Clear" (Escape key), used for clearing the display of a calculator app. I think you can actually toggle real Numlock on a Mac with Fn+Numlock. I'll use Option+Numlock (physical Super+Numlock, logical Alt+Numlock on a PC keyboard) as a toggle to turn this "Forced Numpad" feature on and off, but we can also support Fn+Numlock for Apple keyboards where Kinto can actually "see" the Fn key.

This maps onto the non-keypad keys for Linux because GTK apps may not interpret the keys as numbers otherwise.

Here is a working version of this for Linux. Will post a Windows/AHK version when I get a chance to put it together, and then combine them into a PR.

#########################################################
###########   START OF MAC NUMPAD FEATURE   #############
#########################################################
# Force the numpad to always be a numpad, like a Mac keyboard on macOS
# Numlock key becomes "Clear" key for use with calculator (sends Escape)
# Toggle feature on/off with Option+Numlock (Fn+Numlock might work on Apple keyboards)
# Set _mac_numpad var to "False" (no quotes) to disable by default
_mac_numpad = True
_mac_numpad_first_run = True

def mac_numpad_alert():
    global _mac_numpad_first_run
    if _mac_numpad:
        run('notify-send -u critical ALERT "Kinto Mac Numpad is now ENABLED.\
            \rNumlock == Clear (Escape)\
            \rDisable with Option+Numlock."', shell=True)
        print("(DD) Kinto Mac Numpad is now ENABLED.", flush=True)
    # Don't show pointless alert on startup if feature is set to be disabled by default
    if not _mac_numpad and not _mac_numpad_first_run:
        run('notify-send ALERT "Kinto Mac Numpad is now DISABLED.\
            \rRe-enable with Option+Numlock."', shell=True)
        print("(DD) Kinto Mac Numpad is now DISABLED.", flush=True)
    _mac_numpad_first_run = False


mac_numpad_alert()


def toggle_mac_numpad():
    """Toggle the value of the _optspecialchars variable"""
    from subprocess import run
    def _toggle_mac_numpad():
        global _mac_numpad
        _mac_numpad = not _mac_numpad
        mac_numpad_alert()

    return _toggle_mac_numpad


define_keymap(lambda wm_class: wm_class.casefold() not in remotes,{
    C("Alt-Numlock"):       toggle_mac_numpad(),
    C("Fn-Numlock"):        toggle_mac_numpad(),
},"Mac Numpad toggle")

define_keymap(lambda wm_class: wm_class.casefold() not in remotes and _mac_numpad is True,{
    C("KP1"):               C("1"),
    C("KP2"):               C("2"),
    C("KP3"):               C("3"),
    C("KP4"):               C("4"),
    C("KP5"):               C("5"),
    C("KP6"):               C("6"),
    C("KP7"):               C("7"),
    C("KP8"):               C("8"),
    C("KP9"):               C("9"),
    C("KP0"):               C("0"),
    C("KPDot"):             C("Dot"),
    C("Numlock"):           C("Esc"),
},"Mac Numpad")

#######################################################
###########   END OF MAC NUMPAD FEATURE   #############
#######################################################

[RedBearAK]

@rbreaves

Bundled the Linux and Windows versions together in PR #744.