pango-clock.py

#!/bin/env python2

import gi
gi.require_version('Gtk', '3.0')
gi.require_version('PangoCairo', '1.0')
from gi.repository import Gtk, GLib, Pango, PangoCairo
from datetime import datetime

class DigitalClock(Gtk.DrawingArea):
    def __init__(self):
        super(DigitalClock, self).__init__()

        self.connect("draw", self.draw)
        self._font = Pango.FontDescription("Monospace 25")

        GLib.timeout_add(1000, self.update)

    def draw(self, widget, context):
        rect = self.get_allocation()
        context.rectangle(rect.x, rect.y, rect.width, rect.height)
        context.set_source_rgb(0.1, 0.1, 0.1)
        context.fill()

        context.set_source_rgb(0.8, 0.8, 0.8)
        self.draw_text(context, rect)
        return False

    def draw_text(self, context, rect):
        text = u"{:%H:%M:%S}".format(datetime.now())
        layout = PangoCairo.create_layout(context)
        layout.set_font_description(self._font)
        layout.set_text(text, len(text))

        text_rect = layout.get_extents().logical_rect
        x = rect.x + (rect.width - text_rect.width/Pango.SCALE)/2
        y = rect.y + (rect.height - text_rect.height/Pango.SCALE)/2
        context.move_to(x, y)

        PangoCairo.update_layout(context, layout)
        PangoCairo.show_layout(context, layout)

    def update(self):
        self.queue_draw()
        return True

def main():
    win = Gtk.Window()
    clock = DigitalClock()
    win.add(clock)
    win.connect("delete-event", Gtk.main_quit)
    win.show_all()
    Gtk.main()

if __name__ == "__main__":
    main()