Windows key event handler.

def _handle_windows(self, event):
        """Windows key event handler."""
        vkey = self._keyname(event.GetKey())
        if event.Message in self.KEYS_UP + self.KEYS_DOWN:
            if vkey in self.MODIFIERNAMES:
                self._realmodifiers[vkey] = event.Message in self.KEYS_DOWN
                self._modifiers[self.MODIFIERNAMES[vkey]] = self._realmodifiers[vkey]
        if event.Message not in self.KEYS_DOWN:
            return True

        is_altgr = False
        if (vkey, event.IsExtended()) in self.NUMPAD_SPECIALS:
            key = vkey = "Numpad-" + vkey
        elif not event.Ascii or vkey.startswith("Numpad"):
            key = vkey
        else:
            is_altgr = event.Ascii in self.ALT_GRS
            key = self._keyname(unichr(event.Ascii))

        if DEBUG: print("Adding key %s (real %s)" % (key.encode("utf-8"), vkey.encode("utf-8")))
        self._output(type="keys", key=key, realkey=vkey)

        if vkey not in self.MODIFIERNAMES and not is_altgr:
            modifier = "-".join(k for k in ["Ctrl", "Alt", "Shift", "Win"]
                                if self._modifiers[k])
            if modifier and modifier != "Shift": # Shift-X is not a combo
                if self._modifiers["Ctrl"] and event.Ascii:
                    key = self._keyname(unichr(event.KeyID))
                realmodifier = "-".join(k for k, v in self._realmodifiers.items() if v)
                realkey = "%s-%s" % (realmodifier, key)
                key = "%s-%s" % (modifier, key)
                if DEBUG: print("Adding combo %s (real %s)" % (key.encode("utf-8"), realkey.encode("utf-8")))
                self._output(type="combos", key=key, realkey=realkey)

        if DEBUG:
            print("CHARACTER: %r" % key)
            print('GetKey: {0}'.format(event.GetKey()))  # Name of the virtual keycode, str
            print('IsAlt: {0}'.format(event.IsAlt()))  # Was the alt key depressed?, bool
            print('IsExtended: {0}'.format(event.IsExtended()))  # Is this an extended key?, bool
            print('IsInjected: {0}'.format(event.IsInjected()))  # Was this event generated programmatically?, bool
            print('IsTransition: {0}'.format(event.IsTransition()))  #Is this a transition from up to down or vice versa?, bool
            print('ASCII: {0}'.format(event.Ascii))  # ASCII value, if one exists, str
            print('KeyID: {0}'.format(event.KeyID))  # Virtual key code, int
            print('ScanCode: {0}'.format(event.ScanCode))  # Scan code, int
            print('Message: {0}'.format(event.Message))  # Name of the virtual keycode, str
            print()
        return True