3.3 KiB
DPI scaling
Qubes OS passes on dom0's screen resolution to VMs (this can be seen in the output of xrandr
) but doesn't pass on dom0's dpi value. Recent distributions have automatic scaling depending on the screen's resolution (eg. in fedora if the vertical resolution is greater than 1200px) but for a variety of reasons one may have to set a custom dpi scaling value.
Dom0
The simplest way to set dpi scaling in dom0 is to use the desktop environment's custom dpi feature:
- Xfce: Qubes Menu → System Tools → Appearance → Fonts tab: Custom DPI setting:
xxx
- KDE: Qubes Menu → System Settings → Font → Force font dpi:
xxx
Replace xxx
with a number that fits your setup and is a multiple of 6, as numbers that aren't sometimes result in annoying rounding errors that cause adjacent bitmap font sizes to not increment and decrement linearly.
VMs
The procedure for setting DPI scaling depends on the presence of the /usr/libexec/gsd-xsettings
daemon, usually provided by the gnome-settings-daemon
package:
- without
/usr/libexec/gsd-xsettings
running, applications honor theXft.dpi
X resource, which we can use for scaling. - with
/usr/libexec/gsd-xsettings
running, applications are prevented from using theXft.dpi
resource so gnome specific commands have to used.
Notes:
- the official
fedora-xx
template hasgnome-settings-daemon
installed by default while thefedora-xx-minimal
template doesn't. - DPI scaling with
xterm
(or any glib apps) requires the use of a xft font:-
for
xterm
, ctrl - right click in the terminal's windows and select 'TrueType Fonts' (make sure you have such fonts installed). -
or more generally, set the
faceName
Xresource, eg.:*faceName: DejaVu Sans Mono:size=14:antialias=true
You may do so temporarily with the
xrdb -merge
command, or permanently in aXresources
file (see section below).
-
VMs without gsd-xsettings
Get the current value of Xft.dpi
:
xrdb -query | grep Xft.dpi
Test with a different dpi value: in a terminal issue the following command and then start an application to check that the menus/fonts' size is increased/decreased; replace '144' with the value set in dom0 (it's possible to set a different value in VMs though):
echo Xft.dpi: 144 | xrdb -merge
Once you found a value that fits your setup you'll likely want to permanently set the Xft.dpi
resource. You can do so on a per-template or per-VM basis:
- add (or modify)
Xft.dpi: xxx
in the TemplateVM's Xresource file (/etc/X11/Xresources
or/etc/X11/Xresources/x11-common
for whonix-ws-template). - or, add
Xft.dpi: xxx
to$HOME/.Xresources
in each AppVM.
VMs with gsd-xsettings
Use the gsettings
command (replace 2
and 0.75
to suit your needs ; the first value must be an integer though):
gsettings set org.gnome.desktop.interface scaling-factor 2
gsettings set org.gnome.desktop.interface text-scaling-factor 0.75
Resources
- ARCH Linux HiDPI page: https://wiki.archlinux.org/index.php/HiDPI
- Related official issue: https://github.com/QubesOS/qubes-issues/issues/1951
- Mozilla DPI-related Font Size Issues on Unix: https://www-archive.mozilla.org/unix/dpi.html
Contributors: @taradiddles