#!/usr/bin/python3

# This script sets the display scale factor to 2, for use on 4K displays where everything is too small without scaling.

import dbus

new_scale = 2.0

# https://gitlab.gnome.org/GNOME/mutter/-/blob/main/data/dbus-interfaces/org.gnome.Mutter.DisplayConfig.xml
bus_name = "org.gnome.Mutter.DisplayConfig"
object_path = "/org/gnome/Mutter/DisplayConfig"

session_bus = dbus.SessionBus()
display_config_object = session_bus.get_object(bus_name, object_path)
display_config_intf = dbus.Interface(display_config_object, dbus_interface=bus_name)

serial, physical_monitors, logical_monitors, properties = display_config_intf.GetCurrentState()

current_mode_id = {}
for ((connector, _, _, _), modes, monitor_properties) in physical_monitors:
    for (mode_id, width, height, rate, preferred_scale, supported_scales, mode_properties) in modes:
        if mode_properties.get("is-current", False):
            current_mode_id[connector] = mode_id

scaled_logical_monitors = [
    (layout_x, layout_y, new_scale, transform, primary, [
        (connector, current_mode_id[connector], {}) for (connector, _, _, _) in monitors
    ])
    for (layout_x, layout_y, scale, transform, primary, monitors, monitor_properties) in logical_monitors
]

apply_properties = {}
if "layout-mode" in properties and properties.get("supports-changing-layout-mode", False):
    apply_properties["layout-mode"] = properties["layout-mode"]

method = 1 # temporary
display_config_intf.ApplyMonitorsConfig(serial, method, scaled_logical_monitors, apply_properties)