nixpkgs/nixos/modules/services/x11/desktop-managers/default.nix
Eelco Dolstra 29027fd1e1 Rewrite ‘with pkgs.lib’ -> ‘with lib’
Using pkgs.lib on the spine of module evaluation is problematic
because the pkgs argument depends on the result of module
evaluation. To prevent an infinite recursion, pkgs and some of the
modules are evaluated twice, which is inefficient. Using ‘with lib’
prevents this problem.
2014-04-14 16:26:48 +02:00

77 lines
2.1 KiB
Nix

{ config, lib, pkgs, ... }:
with lib;
let
xcfg = config.services.xserver;
cfg = xcfg.desktopManager;
# If desktop manager `d' isn't capable of setting a background and
# the xserver is enabled, the `feh' program is used as a fallback.
needBGCond = d: ! (d ? bgSupport && d.bgSupport) && xcfg.enable;
in
{
# Note: the order in which desktop manager modules are imported here
# determines the default: later modules (if enabled) are preferred.
# E.g., if KDE is enabled, it supersedes xterm.
imports = [ ./none.nix ./xterm.nix ./xfce.nix ./kde4.nix ./e17.nix ./gnome3.nix ./xbmc.nix ];
options = {
services.xserver.desktopManager = {
session = mkOption {
internal = true;
default = [];
example = singleton
{ name = "kde";
bgSupport = true;
start = "...";
};
description = ''
Internal option used to add some common line to desktop manager
scripts before forwarding the value to the
<varname>displayManager</varname>.
'';
apply = list: {
list = map (d: d // {
manage = "desktop";
start = d.start
+ optionalString (needBGCond d) ''
if test -e $HOME/.background-image; then
${pkgs.feh}/bin/feh --bg-scale $HOME/.background-image
fi
'';
}) list;
needBGPackages = [] != filter needBGCond list;
};
};
default = mkOption {
type = types.str;
default = "";
example = "none";
description = "Default desktop manager loaded if none have been chosen.";
apply = defaultDM:
if defaultDM == "" && cfg.session.list != [] then
(head cfg.session.list).name
else if any (w: w.name == defaultDM) cfg.session.list then
defaultDM
else
throw "Default desktop manager ($(defaultDM)) not found.";
};
};
};
config = {
services.xserver.displayManager.session = cfg.session.list;
environment.systemPackages =
mkIf cfg.session.needBGPackages [ pkgs.feh ];
};
}