Configuration overhaul (#30)

- Settings are no longer compiled in, only loaded during runtime
- Settings can be changed dynamically (with set/2 and add/2)
- Any setting can be omitted, because everything has a default value
- Default settings are installed to /etc/plwm/config.pl
- reload_config/0 re-reads config file
- dump_settings/1 dumps current setting values to a file
- Config files must NOT use module declarations (settings are in the global namespace)
- bar_class/2 became bar_classes/1 taking a list (all settings must have arity 1 and be deterministic)

Author: Seeker04

Dockerfile

@@ -9,9 +9,6 @@ ENV DEBIAN_FRONTEND=noninteractive
 # Use UTF-8 encoding, otherwise swipl throws "Illegal multibyte Sequence" errors
 ENV LANG=en_US.UTF-8
 
-# Set user config directory
-ENV XDG_CONFIG_HOME=/home/testuser/.config
-
 # Update package list and install required packages
 RUN apt-get update &&   \
     apt-get install -y  \

Makefile

@@ -14,16 +14,11 @@ LDFLAGS = -shared -lX11 -lXft -lXrandr
 SWIFLAGS = -p foreign=$(INSTALLDIR_LIB) \
            --goal=main --toplevel=halt --stand_alone=true -O -o plwm -c src/plwm.pl
 
-INSTALLDIR     = /usr/local/bin
+INSTALLDIR_BIN = /usr/local/bin
 INSTALLDIR_LIB = /usr/local/lib
+INSTALLDIR_CNF = /etc/plwm
 INSTALLDIR_MAN = /usr/local/share/man/man1
 
-ifdef XDG_CONFIG_HOME
-CONFIG_PATH = $(XDG_CONFIG_HOME)/plwm
-else
-CONFIG_PATH = $(HOME)/.config/plwm
-endif
-
 #================================== Build =====================================
 
 plwm: plx.so src/*.pl
@@ -67,18 +62,16 @@ test:
 VERSION = ${shell sed -n 's/^version(\([0-9.]\+\))\.$$/\1/p' src/plwm.pl}
 
 install: plwm
-	install -D --mode=755 plwm $(INSTALLDIR)/plwm
+	install -D --mode=755 plwm $(INSTALLDIR_BIN)/plwm
 	install -D --mode=755 plx.so $(INSTALLDIR_LIB)/plx.so
+	install -D --mode=644 -C --backup=numbered config/config.pl $(INSTALLDIR_CNF)/config.pl
 	mkdir -p $(INSTALLDIR_MAN)
 	sed 's/VERSION/$(VERSION)/' < docs/plwm.1 > $(INSTALLDIR_MAN)/plwm.1
 	chmod 644 $(INSTALLDIR_MAN)/plwm.1
 
 uninstall:
-	rm -f $(INSTALLDIR)/plwm \
+	rm -f $(INSTALLDIR_BIN)/plwm \
 	      $(INSTALLDIR_LIB)/plx.so \
 	      $(INSTALLDIR_MAN)/plwm.1
-
-mkconfig:
-	install -D src/config.pl $(CONFIG_PATH)/config.pl
-	sed -i 's/module(config/module(runtime_config/' $(CONFIG_PATH)/config.pl
+	[ -d $(INSTALLDIR_CNF) ] && echo "Note: $(INSTALLDIR_CNF) is kept" || true
 

README.md

@@ -181,24 +181,16 @@ then you'll have a triple stack layout where your windows will be evenly spread
 
 ## Configuration
 
-Configuration is done by modifying [config.pl](src/config.pl) then recompiling with `make && sudo make install`.
+`sudo make install` installs the [default configuration](config/config.pl) to `/etc/plwm/config.pl`. This file can be copied to user config directories.
 
-plwm will also attempt reading configuration when it starts from the first file among
+plwm attempts reading configuration when it starts from the first file among
 - `$XDG_CONFIG_HOME/plwm/config.pl`
 - `$HOME/.config/plwm/config.pl`
 - `/etc/plwm/config.pl`
 
-if any exists, so users don't have to recompile each time if they don't wish to. Any values read from the runtime config will override the compiled in settings.
-
 A custom path can be specified with the `-c` flag.
 
-**Attention:** the module name in the runtime config must be `runtime_config`!
-
-You can run:
-
-`$ make mkconfig`
-
-which takes `src/config.pl` and generates the runtime config from it. Then keep modifying the latter while leaving the former in the default state. Or you can use the source one as a stable config and the runtime one for experimental overrides...
+**Note:** a reinstall will overwrite `/etc/plwm/config.pl`, however a backup is always created if there is any difference.
 
 While cooking your config, you can use the `-C` flag to quickly and easily check its validity.
 
@@ -223,7 +215,7 @@ While cooking your config, you can use the `-C` flag to quickly and easily check
 | `ws_format`                | string with a \~w **or**<br/>string with a \~d followed by a \~w<br>**Default:** "\~w"  | Format of empty workspaces on bars (~d = index, ~w = name) |
 | `ws_format_occupied`       | string with a \~w **or**<br/>string with a \~d followed by a \~w<br>**Default:** "▘\~w" | Format of occupied workspaces on bars |
 | `layout_default_overrides` | list of (Monitor, Workspace -> Nmaster, Mfact, Layout)<br>**Default:** [] | Overrides of the 3 values to specific monitors and/or workspaces (explained [here](#layout-overrides)) |
-| `bar_class`                | the two strings from bar's WM_CLASS,<br/>query with [xprop(1)](https://linux.die.net/man/1/xprop)<br>**Default:** "polybar", "Polybar" | Space will be reserved for matching windows and they cannot be focused, resized, etc. |
+| `bar_classes`              | list of string pairs from bar's WM_CLASS,<br/>query with [xprop(1)](https://linux.die.net/man/1/xprop)<br>**Default:** ["polybar"-"Polybar"] | Space will be reserved for matching windows and they cannot be focused, resized, etc. |
 | `bar_placement`            | follow_focus, static<br>**Default:** follow_focus               | Determines placement of external bars (explained [here](#layout-overrides)) |
 | `fifo_enabled`             | true or false<br>**Default:** false                             | Whether to spawn a command FIFO<br>(explained [here](#scriptability)) |
 | `fifo_path`                | string<br>**Default:** "/tmp/plwm_fifo"                         | Path of command FIFO                            |
@@ -238,13 +230,31 @@ While cooking your config, you can use the `-C` flag to quickly and easily check
 | `rules`                    | list of (Name, Class, Title -> Monitor, Workspace, Mode)<br>**Default:** [] | Auto place and configure matching windows (explained [here](#rules)) |
 | `hooks`                    | list of (Event -> Action)<br>**Default:** `[start -> writeln("plwm starting"), quit -> writeln("plwm quitting")]` | Run custom logic on certain events (explained [here](#hooks)) |
 
-**Notes**
+**Tips**
 
-In `keymaps/1`, the callback predicates can be arbitrary shell commands using `shellcmd/1`, even whole commandlines (some examples are included in the [default config](src/config.pl)).
+* You can safely remove any setting from your config file, plwm will use the default value for those.
+* In `keymaps/1`, the callback predicates can be arbitrary shell commands using `shellcmd/1`, even whole commandlines (some examples are included in the [default config](config/config.pl)).
+* If you wish to stick to default keymaps mostly, with only a few changes and feel redundant to list the whole table in your config, you can simply omit the `keymaps/1` setting and add your changes as a `start` hook like this:
+
+```Prolog
+hooks([
+  start -> (
+    add(keymaps, super + g -> shellcmd("gcolor2")),    % add new
+    add(keymaps, super + l -> switch_workspace(next)), % overwrite existing
+    add(keymaps, super + f -> none)                    % remove existing
+  )
+]).
+```
+
+**Changing settings during runtime**
+
+* `set/2` and `add/2` can be used to overwrite or append to existing settings, respectively. You can invoke them via a keymap, the [command fifo](#scriptability) or the [command menu](#menus).
+* The whole configuration file can be reloaded by calling `reload_config/0`.
+* You can use `dump_settings/1` to dump all current settings to a file.
 
 ## External bars
 
-First, you must specify `bar_class/2` based on the WM_CLASS properties of your bars, which you can find out using [xprop(1)](https://linux.die.net/man/1/xprop). Then you can both:
+First, you must specify `bar_classes/1` based on the WM_CLASS properties of your bars, which you can find out using [xprop(1)](https://linux.die.net/man/1/xprop). Then you can both:
 * manually start/close bars while plwm is already running
 * automatically start bars using `hooks/1` and its `start` event in the config
 
@@ -275,7 +285,7 @@ alt + b         -> shellcmd("pkill -fx 'polybar top' || polybar top"),
 alt + shift + b -> shellcmd("pkill -fx 'polybar bot' || polybar bot")
 ```
 
-**Note:** if you are using polybar, **do not enable** its `override-redirect = true` setting (it can even crash plwm in some cases)! Reasoning: plwm itself handles all bars (anything that matches `bar_class`, not just polybar) the intended way: bars cannot be focused, grabbed, moved or resized; tiling windows will never cover them (but you can drag floating windows above them); fullscreen windows will always cover them.
+**Note:** if you are using polybar, **do not enable** its `override-redirect = true` setting (it can even crash plwm in some cases)! Reasoning: plwm itself handles all bars (anything that matches `bar_classes`, not just polybar) the intended way: bars cannot be focused, grabbed, moved or resized; tiling windows will never cover them (but you can drag floating windows above them); fullscreen windows will always cover them.
 
 ## Multi-monitor
 
@@ -538,9 +548,9 @@ For known problems, see [the Issues with bug labels](https://github.com/Seeker04
 
 First and foremost, if you find any bugs, please [create a GitHub issue](https://github.com/Seeker04/plwm/issues/new), preferably, with all details you can provide. (First, please check if it's not reported already).
 
-If you have a feature request, please do the same.
+If you have a feature request or questions, feel free to [open discussions](https://github.com/Seeker04/plwm/discussions).
 
-Any code contribution is also welcome. Especially if it solves some known issue. For brand new ideas, I recommend creating an issue first, so we can discuss it.
+Any code contribution is also welcome. Especially if it solves some known issue. For brand new ideas, I recommend creating a discussion first.
 
 Please read the [Development Guide](docs/development_guide.md).
 
@@ -570,15 +580,17 @@ export _JAVA_AWT_WM_NONREPARENTING=1
 ```
 to your `.xinitrc` should solve this problem.
 
-**plwm doesn't start! What's going on?**
+**My configuration doesn't work!**
 
-Most likely your configuration is faulty. Run `plwm --check`, then you should see the problem.
+Run `plwm --check`, then you should see the problem. Consult the [table here](#configuration) to see the proper type for each setting. E.g. make sure you use double quotes for _strings_ and single quotes for _atoms_.
 
-If you don't see a config error, then please report it as an issue. Preferably by attaching any message plwm dumps to stderr or to its logfile with `-l`.
+If you don't see any error, then please report it as an issue by attaching your config and any message plwm dumps to stderr or to its logfile with `-l`.
 
 **Something is missing...**
 
-plwm is minimal in the sense that it doesn't try to solve problems outside of a window manager's domain, especially if they are easily served by other programs (see [here](https://en.wikipedia.org/wiki/Unix_philosophy)):
+tl;dr plwm is a window manager, not a full-fledged desktop environment.
+
+plwm is minimal in the sense that it doesn't try to solve problems outside of a wm's domain, especially if they are easily served by other programs (see [here](https://en.wikipedia.org/wiki/Unix_philosophy)):
 
 * Don't want a status bar? You're set. Want one (or more)? Here are a few: [polybar](https://polybar.github.io/), [lemonbar](https://github.com/LemonBoy/bar), [xmobar](https://codeberg.org/xmobar/xmobar)
 * Want transparent windows or other effects? Use a compositor like [picom](https://wiki.archlinux.org/title/Picom)

src/config.pl config/config.plsrc/config.pl renamed to config/config.pl

@@ -1,10 +1,18 @@
 % MIT License, Copyright (c) 2023-2025 Barnabás Zahorán, see LICENSE
 %
+% This is plwm's default configuration installed under /etc
+%
+% You can revert this file by reinstalling plwm (if it differs, a backup will be kept)
+%
+% Users can create their own configs under
+%     $XDG_CONFIG_HOME/plwm/config.pl
+% or
+%     $HOME/.config/plwm/config.pl
+% to overrule this file
+%
 % Note: there is extensive commenting in this file, as well as arbitrary examples
 % for easier understanding. Feel free to remove them once you're familiar with the settings
 
-:- module(config, []).
-
 %*********************************  Layout  ***********************************
 
 default_nmaster(1).      % initial number of master windows for master-stack layouts
@@ -79,10 +87,9 @@
 %**********************************  Bars  ************************************
 
 % Use xprop(1) or a similar tool to find out the WM_CLASS property of your bar
-% You may specify only the name: ("name", _) or only the class: (_, "class")
-% List multiple bar_class lines below if you use multiple different bars
-% You can delete the line, if you don't use any bar
-bar_class("polybar", "Polybar").
+% You may specify only the name: "name"-_ or only the class: _-"class"
+% List multiple bar_classes if you use multiple different bars
+bar_classes(["polybar"-"Polybar"]).
 
 % Possible values:
 %   follow_focus: space will be reserved for bars on all monitors and bars will
@@ -243,22 +250,22 @@
 
   %%%%% Custom mapping examples %%%%%
 
+  % Launch applications
+  ctrl + shift + space      ->  shellcmd("alacritty")           ,
+  alt + a                   ->  shellcmd("dmenu_run -l 20 -p run")
+
   % Toggle status bar
-  alt + b                   ->  shellcmd("pkill polybar || polybar top") ,
+ %alt + b                   ->  shellcmd("pkill polybar || polybar top") ,
  %alt + b                   ->  shellcmd("pkill polybar || (polybar top & polybar bot)") ,
  %alt + b                   ->  shellcmd("pkill -fx 'polybar top' || polybar top") ,
  %alt + shift + b           ->  shellcmd("pkill -fx 'polybar bot' || polybar bot") ,
 
-  % Launch applications
-  ctrl + shift + space      ->  shellcmd("alacritty")           ,
-  alt + a                   ->  shellcmd("dmenu_run -c -l 20")  ,
-
   % Special keys (see xf86names.pl for all such keys)
-  "AudioRaiseVolume"        ->  shellcmd("pulseaudio-ctl up")   ,
-  "AudioLowerVolume"        ->  shellcmd("pulseaudio-ctl down") ,
-  "AudioMute"               ->  shellcmd("pulseaudio-ctl mute") ,
-  "MonBrightnessUp"         ->  shellcmd("xbacklight -inc 1")   ,
-  "MonBrightnessDown"       ->  shellcmd("xbacklight -dec 1")
+ %"AudioRaiseVolume"        ->  shellcmd("pulseaudio-ctl up")   ,
+ %"AudioLowerVolume"        ->  shellcmd("pulseaudio-ctl down") ,
+ %"AudioMute"               ->  shellcmd("pulseaudio-ctl mute") ,
+ %"MonBrightnessUp"         ->  shellcmd("xbacklight -inc 1")   ,
+ %"MonBrightnessDown"       ->  shellcmd("xbacklight -dec 1")
 ]).
 
 
@@ -288,9 +295,9 @@
 
 rules([
 %  name      class     title                 monitor     wspace    mode
-  (_      ,  _      ,  exact("gcolor2")  ->  _        ,  _      ,  [center, center, 1/3, 1/3]),
-  (_      ,  _      ,  "Firefox"         ->  "eDP-1"  ,  'www'  ,  fullscreen                ),
-  ("Bar"  ,  "Baz"  ,  _                 ->  "HDMI-1" ,  '1'    ,  [700, 250, _, _]          )
+% ( _      ,  _      ,  exact("gcolor2")  ->  _        ,  _      ,  [center, center, 1/3, 1/3] ),
+% ( _      ,  _      ,  "Firefox"         ->  "eDP-1"  ,  'www'  ,  fullscreen                 ),
+% ( "Bar"  ,  "Baz"  ,  _                 ->  "HDMI-1" ,  '1'    ,  [700, 250, _, _]           )
 ]).
 
 % You can find out the name, class and title values of windows using xprop(1):

docs/development_guide.md

@@ -51,10 +51,10 @@ User interaction is possible by three methods:
 | ----------------------------------- | ----------------------------------------- |
 | [plwm.pl](../src/plwm.pl)           | entry point, event loop and wm logic      |
 | [animation.pl](../src/animation.pl) | window animations                         |
-| [config.pl](../src/config.pl)       | default configuration                     |
 | [fifo.pl](../src/fifo.pl)           | command fifo implementation               |
 | [layout.pl](../src/layout.pl)       | layout definitions                        |
 | [menu.pl](../src/menu.pl)           | menu commands                             |
+| [setting.pl](../src/setting.pl)     | settings related predicates               |
 | [utils.pl](../src/utils.pl)         | common utilities used by multiple modules |
 | [xf86names.pl](../src/xf86names.pl) | definitions for special keys              |
 | [plx.c](../src/plx.c)               | libX11 bindings                           |

src/fifo.pl

@@ -4,18 +4,18 @@
 
 %! setup_fifo() is det
 %
-%  If config:fifo_enabled/1 and config:fifo_path/1 are set, attempts to create
+%  If fifo_enabled/1 and fifo_path/1 are set, attempts to create
 %  a named pipe with mkfifo(1).
 %  If the fifo is created, its path is passed to fifo:process_fifo/1 on a detached thread.
 setup_fifo() :-
-	optcnf_then(fifo_enabled(true), optcnf_then(fifo_path(FifoPath), (
+	(fifo_enabled(true), fifo_path(FifoPath) ->
 		catch(delete_file(FifoPath), _, true), % cleanup from previous execution
 		string_concat("mkfifo ", FifoPath, MkFifoCmd), % no swipl predicate for this
 		shell(MkFifoCmd, ExitCode),
 		(ExitCode == 0 ->
 			thread_create(fifo:process_fifo(FifoPath), _, [detached(true)])
 		; writeln(user_error, "Could not spawn command fifo!"))
-	)))
+	; true)
 .
 
 %! process_fifo(++FifoPath:string) is det