import math
import sys

import gi

gi.require_version("Gtk", "3.0")
from gi.repository import Gtk  # noqa
import cairo  # noqa


class TestWin(Gtk.Window):
    WINDOW_POPUP = 1

    def __init__(self):
        Gtk.Window.__init__(self, type=self.WINDOW_POPUP)

        self._default_monitor = 0
        self.make_fullscreen()
        self.label = Gtk.Label(label="Hallo! :)")
        self.label.show()
        self.add(self.label)

        self.make_rgba()
        self.set_app_paintable(True)
        self.connect("draw", self.on_draw)

        self.show()
        self.make_untouchable()

    def make_rgba(self):
        self.screen = self.get_screen()
        self.visual = self.screen.get_rgba_visual()
        if self.visual is None or not self.screen.is_composited():
            print("ERROR: You do not appear to be running a composite manager")
            sys.exit(1)
        else:
            self.set_visual(self.visual)

    def make_fullscreen(self):
        geo = self.get_screen_size(self._default_monitor)
        self.move(geo.x, geo.y)
        self.resize(geo.width, geo.height)
 
    def get_screen_size(self, monitor):
        return self.get_screen().get_monitor_geometry(monitor)

    def on_draw(self, widget, cr):
        # make everything transparent
        cr.set_source_rgba(1.0, 1.0, 1.0, 0.1)
        cr.set_operator(cairo.OPERATOR_SOURCE)
        cr.paint()
        cr.set_operator(cairo.OPERATOR_OVER)

        # draw the circle
        w, h = self.get_size()
        cr.translate(w / 2, h / 2)
        cr.set_source_rgba(0.7, 0.3, 0.0, 0.6)
        cr.arc(0, 0, 10, 0, 2 * math.pi)
        cr.stroke_preserve()
        cr.fill()

    def make_untouchable(self):
        self.input_shape_combine_region(cairo.Region(cairo.RectangleInt(0, 0, 0, 0)))

    def run(self):
        Gtk.main()
        return 0


if __name__ == "__main__":
    app = TestWin()
    sys.exit(app.run())