arctica-greeter-check-hidpi

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

# Copyright (C) 2017 Clement Lefebvre <clement.lefebvre@linuxmint.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 3 as
# published by the Free Software Foundation.
#
# This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
#
# Authors: Clement Lefebvre <clement.lefebvre@linuxmint.com>

import gi
gi.require_version('Gdk', '3.0')
from gi.repository import Gdk
import sys
import syslog
import os

HIDPI_LIMIT = 192

def get_window_scale():
    window_scale = 1
    try:
        display = Gdk.Display.get_default()
        if display != None:
            monitor = display.get_primary_monitor()
            rect = monitor.get_geometry()
            width_mm = monitor.get_width_mm()
            height_mm = monitor.get_height_mm()
            monitor_scale = monitor.get_scale_factor()

            # Return 1 if the screen size isn't available (some TVs report their aspect ratio instead ... 16/9 or 16/10)
            if ((width_mm == 160 and height_mm == 90) \
                or (width_mm == 160 and height_mm == 100) \
                or (width_mm == 16 and height_mm == 9) \
                or (width_mm == 16 and height_mm == 10)):
                return 1

            if rect.height * monitor_scale < 1500:
                return 1

            if width_mm > 0 and height_mm > 0:
                width_inch = width_mm / 25.4
                height_inch = height_mm / 25.4
                dpi_x = rect.width * monitor_scale / width_inch
                dpi_y = rect.height * monitor_scale / height_inch
                if dpi_x > HIDPI_LIMIT and dpi_y > HIDPI_LIMIT:
                    window_scale = 2

    except Exception as detail:
        syslog.syslog("Error while detecting hidpi mode: %s" % detail)

    return window_scale

if __name__ == '__main__':
    window_scale = get_window_scale();
    print ("{script}: Window scale is {value}".format(script=os.path.basename(sys.argv[0]), value=window_scale), file=sys.stderr)
    print (window_scale, file=sys.stdout)
    sys.exit(0)