input-remapper/keymapper/gtk/row.py

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# key-mapper - GUI for device specific keyboard mappings
# Copyright (C) 2020 sezanzeb <proxima@hip70890b.de>
#
# This file is part of key-mapper.
#
# key-mapper is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# key-mapper is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with key-mapper.  If not, see <https://www.gnu.org/licenses/>.


"""A single, configurable key mapping."""


import gi
gi.require_version('Gtk', '3.0')
gi.require_version('GLib', '2.0')
from gi.repository import Gtk, GLib

from keymapper.state import custom_mapping
from keymapper.logger import logger
from keymapper.reader import keycode_reader


CTX_KEYCODE = 2


class Row(Gtk.ListBoxRow):
    """A single, configurable key mapping."""
    __gtype_name__ = 'ListBoxRow'

    def __init__(self, delete_callback, window, keycode=None, character=None):
        """Construct a row widget."""
        super().__init__()
        self.device = window.selected_device
        self.window = window
        self.delete_callback = delete_callback

        self.character_input = None
        self.keycode = None

        self.put_together(keycode, character)

    def get_keycode(self):
        keycode = self.keycode.get_label()
        return int(keycode) if keycode else None

    def get_character(self):
        character = self.character_input.get_text()
        return character if character else None

    def start_watching_keycodes(self, *args):
        """Start to periodically check if a keycode has been pressed.

        This also includes e.g. middle mouse buttons, as opposed to
        get_keycode from gdk events.
        """
        keycode_reader.clear()

        def iterate():
            self.check_newest_keycode()
            return self.keycode.is_focus() and self.window.window.is_active()

        GLib.timeout_add(1000 / 30, iterate)

    def check_newest_keycode(self):
        """Check if a keycode has been pressed and if so, display it."""
        new_keycode = keycode_reader.read()
        previous_keycode = self.get_keycode()
        character = self.get_character()

        # no input
        if new_keycode is None:
            return

        # keycode didn't change, do nothing
        if new_keycode == previous_keycode:
            return

        # keycode is already set by some other row
        if custom_mapping.get_character(new_keycode) is not None:
            msg = f'Keycode {new_keycode} is already mapped'
            logger.info(msg)
            self.window.get('status_bar').push(CTX_KEYCODE, msg)
            return

        # it's legal to display the keycode
        self.window.get('status_bar').remove_all(CTX_KEYCODE)
        self.keycode.set_label(str(new_keycode))
        # switch to the character, don't require mouse input because
        # that would overwrite the key with the mouse-button key if
        # the current device is a mouse
        self.window.window.set_focus(self.character_input)
        self.highlight()

        # the character is empty and therefore the mapping is not complete
        if character is None:
            return

        # else, the keycode has changed, the character is set, all good
        custom_mapping.change(previous_keycode, new_keycode, character)

    def highlight(self):
        """Mark this row as changed."""
        self.get_style_context().add_class('changed')

    def unhighlight(self):
        """Mark this row as unchanged."""
        self.get_style_context().remove_class('changed')

    def on_character_input_change(self, entry):
        keycode = self.get_keycode()
        character = self.get_character()

        self.highlight()

        if keycode is not None:
            custom_mapping.change(
                previous_keycode=None,
                new_keycode=keycode,
                character=character
            )

    def put_together(self, keycode, character):
        """Create all child GTK widgets and connect their signals."""
        delete_button = Gtk.EventBox()
        delete_button.add(Gtk.Image.new_from_icon_name(
            'window-close',
            Gtk.IconSize.BUTTON
        ))
        delete_button.connect(
            'button-press-event',
            self.on_delete_button_clicked
        )
        delete_button.set_margin_start(5)
        delete_button.set_margin_end(5)

        keycode_input = Gtk.ToggleButton()

        if keycode is not None:
            keycode_input.set_label(str(keycode))

        # to capture regular keyboard keys or extra-mouse keys
        keycode_input.connect(
            'focus-in-event',
            self.start_watching_keycodes
        )

        # make the togglebutton go back to its normal state when doing
        # something else in the UI
        keycode_input.connect(
            'focus-out-event',
            lambda *args: keycode_input.set_active(False)
        )

        character_input = Gtk.Entry()
        character_input.set_alignment(0.5)
        character_input.set_width_chars(4)
        character_input.set_has_frame(False)
        if character is not None:
            character_input.set_text(character)
        character_input.connect(
            'changed',
            self.on_character_input_change
        )

        box = Gtk.Box(orientation=Gtk.Orientation.HORIZONTAL)
        box.set_homogeneous(True)
        box.set_spacing(2)
        box.pack_start(keycode_input, expand=True, fill=True, padding=0)
        box.pack_start(character_input, expand=True, fill=True, padding=0)
        box.pack_start(delete_button, expand=True, fill=False, padding=0)
        box.show_all()

        self.add(box)
        self.show_all()

        self.character_input = character_input
        self.keycode = keycode_input

    def on_delete_button_clicked(self, *args):
        """Destroy the row and remove it from the config."""
        keycode = self.get_keycode()
        if keycode is not None:
            custom_mapping.clear(keycode)
        self.delete_callback(self)