numeretti/schermetto/num_display.py

#!/usr/bin/env python3

import os
import sys
import argparse
import random

import gi

gi.require_version("Gtk", "3.0")
gi.require_version("PangoCairo", "1.0")
gi.require_version("Gdk", "3.0")
gi.require_version("GLib", "2.0")
from gi.repository import Gtk, Gio, cairo, Pango, Gdk, PangoCairo, GLib


def get_parser():
    p = argparse.ArgumentParser(formatter_class=argparse.ArgumentDefaultsHelpFormatter)
    p.add_argument(
        "--read-only",
        action="store_true",
        dest="readonly",
        help="Display but dont change the number",
    )
    p.add_argument(
        "--stdin",
        action="store_true",
        default=True,
        dest="stdin",
        help="stdin is read and shown",
    )
    p.add_argument("--fullscreen", action="store_true", default=True, dest="fullscreen")
    p.add_argument(
        "--no-fullscreen", action="store_false", default=True, dest="fullscreen"
    )
    p.add_argument("--background", default="#111")
    p.add_argument("--foreground", default="#eee")
    p.add_argument(
        "--invert-every",
        type=float,
        metavar="SECONDS",
        default=60,
        help=(
            "Swap foreground and background periodically; "
            "this is useful to avoid CRT-burning; use <= 0 to disable"
        ),
    )
    return p


class App(Gtk.Application):
    def __init__(self, cli_args, *args, **kwargs):
        super().__init__(
            *args,
            application_id="org.hackmeeting.numeretti",
            flags=Gio.ApplicationFlags.FLAGS_NONE,
            **kwargs
        )
        self.window = None
        self.cli_args = cli_args

    def do_startup(self):
        Gtk.Application.do_startup(self)

        action = Gio.SimpleAction.new("quit", None)
        action.connect("activate", self.on_quit)
        self.add_action(action)

        # self.set_app_menu(…)

    def do_activate(self):
        # We only allow a single window and raise any existing ones
        if not self.window:
            # Windows are associated with the application
            # when the last one is closed the application shuts down
            self.window = AppWindow(application=self, title="Main Window")

        self.window.present()

    def on_quit(self, action, param):
        self.quit()


def get_color(description: str) -> Gdk.RGBA:
    rgba = Gdk.RGBA()
    ret = rgba.parse(description)
    if ret is False:
        raise ValueError("Error parsing color! %s" % description)
    return rgba


class AppWindow(Gtk.ApplicationWindow):
    def __init__(self, *args, **kwargs):
        self.app = kwargs["application"]
        super().__init__(*args, **kwargs)
        self.text = ""
        self.buffer = ""
        self.rotation = 0
        self.invert_colors = False
        self.drawing_area = Gtk.DrawingArea()
        self.drawing_area.set_can_focus(True)
        self.drawing_area.connect("draw", self.redraw)
        vbox = Gtk.Box(orientation=Gtk.Orientation.VERTICAL)
        vbox.pack_start(self.drawing_area, True, True, 0)
        self.add(vbox)
        if self.app.cli_args.fullscreen:
            self.fullscreen()
        self.show_all()
        if self.app.cli_args.stdin:
            os.set_blocking(sys.stdin.fileno(), False)
            GLib.io_add_watch(sys.stdin.fileno(), GLib.IO_IN, self._on_stdin_data)
        if self.app.cli_args.invert_every > 0:
            GLib.timeout_add(self.app.cli_args.invert_every * 1000, self.swap_colors)

    def force_redraw(self):
        self.drawing_area.queue_draw()

    def _on_stdin_data(self, *args, **kwargs):
        max_line_length = 16
        incoming_data = sys.stdin.read(max_line_length)
        if not incoming_data:
            return True
        self.buffer += incoming_data
        if len(self.buffer) == max_line_length:
            self.buffer += '\n'
        if "\n" in self.buffer:
            parts = self.buffer.split("\n")
            self.buffer = parts[-1]
            self.change_text(parts[-2])
        return True

    def change_text(self, text: str):
        self.text = text
        self.force_redraw()

    def swap_colors(self):
        self.invert_colors = not self.invert_colors
        self.force_redraw()
        return True

    @property
    def font(self):
        font = Pango.FontDescription()
        font.set_family("sans-serif")
        font.set_size(200 * Pango.SCALE)

    @property
    def colors(self):
        fg = self.app.cli_args.foreground
        bg = self.app.cli_args.background
        if self.invert_colors:
            fg, bg = bg, fg
        return (fg, bg)

    @property
    def bg(self):
        return get_color(self.colors[1])

    @property
    def fg(self):
        return get_color(self.colors[0])

    def redraw(self, widget, cr):
        # clearly stolen from screen-message. thanks!
        draw = self.drawing_area
        Gdk.cairo_set_source_rgba(cr, self.bg)
        cr.paint()
        layout = draw.create_pango_layout(self.text)
        layout.set_font_description(self.font)
        layout.set_alignment(Pango.Alignment.CENTER)
        w1, h1 = layout.get_pixel_size()
        if w1 and h1:
            w2 = draw.get_allocated_width()
            h2 = draw.get_allocated_height()
            if self.rotation in [0, 2]:
                rw1 = w1
                rh1 = h1
            else:
                rw1 = h1
                rh1 = w1
            s = min(w2 / rw1, h2 / rh1)
            cr.translate(w2 // 2, h2 // 2)
            cr.rotate(0)
            cr.scale(s, s)
            cr.translate(-w1 / 2, -h1 / 2)
            Gdk.cairo_set_source_rgba(cr, self.fg)
            PangoCairo.show_layout(cr, layout)


def main():
    args = get_parser().parse_args()
    app = App(args)
    app.run()


if __name__ == "__main__":
    main()