desk_clock.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

import gi
import cairo
import datetime

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


_SUPPORTS_ALPHA = False


def on_draw(w, cr):
    cr.save()
    if _SUPPORTS_ALPHA:
        cr.set_source_rgba(0.5, 1.0, 0.5, 0.5)    # transparent
    else:
        cr.set_source_rgb(0.5, 1.0, 0.5)          # opaque
    cr.set_operator(cairo.OPERATOR_SOURCE)
    cr.paint()
    cr.restore()


def on_screen_changed(previous_screen):
    global w, _SUPPORTS_ALPHA

    screen = w.get_screen()
    visual = screen.get_rgba_visual()

    if visual:
        # print('Your screen supports alpha channels!')
        _SUPPORTS_ALPHA = True
    else:
        print('Your screen does not support alpha channels!')

    w.set_visual(visual)


def on_window_clicked(w, e):
    w.set_decorated(not w.get_decorated())
    return True


def now_label():
    global r
    now = datetime.datetime.now().strftime('%B\n%A\n%d/%m/%y\n%T').title()
    r.set_markup('<span color="yellow" size="50000">%s</span>' % now)
    return True


w = Gtk.Window()
# UTILITY / DOCK / DESKTOP / NORMAL / DIALOG
w.set_type_hint(Gdk.WindowTypeHint.DESKTOP)
w.set_title('Relógio  @JuniorPolegato')
w.set_position(Gtk.WindowPosition.CENTER_ALWAYS)
w.add_events(Gdk.EventMask.BUTTON_PRESS_MASK)
w.set_app_paintable(True)
w.connect('delete-event', Gtk.main_quit)
w.connect('draw', on_draw)
w.connect('screen_changed', on_screen_changed)
w.connect('button_press_event', on_window_clicked)

a = Gtk.Alignment(xalign=0.5, yalign=0.5, xscale=0.0, yscale=0.0)
w.add(a)

r = Gtk.Label()
r.set_justify(Gtk.Justification.CENTER)
GLib.timeout_add(1000, now_label)
a.add(r)

on_screen_changed(w.get_screen())

w.show_all()

Gtk.main()