xidle-inhibit/README.md

# xidle-inhibit

Makes screen locking with `xautolock` or `xss-lock` respect the "don't lock the screen" requests that apps send, on X11 sessions without a desktop environment (for example a plain window manager like xmonad).

Browsers, Steam, gamemode and other apps ask the desktop not to lock or blank the screen while a video or game is running, through the D-Bus service `org.freedesktop.ScreenSaver`. Without a desktop environment nothing provides that service, so the requests are dropped and the screen locks in the middle of a video. xidle-inhibit provides it:

- While at least one request is active, it pauses X screen blanking and DPMS, and with xautolock also runs `xautolock -disable`. xss-lock locks when the X screensaver starts, so pausing it is enough.
- When the last request is released, it waits a few seconds, then resumes blanking (and runs `xautolock -enable`).

Your locker setup stays as it is; xidle-inhibit only holds it off.

Formerly `xautolock-inhibit`, which supported only xautolock.

## How it works

- Owns `org.freedesktop.ScreenSaver` on the session bus at both `/org/freedesktop/ScreenSaver` and `/ScreenSaver` (apps differ on the path), and implements `Inhibit`, `UnInhibit` and `Lock`.
- Tracks requests per D-Bus client. If a client disconnects without releasing them (for example a browser crash), its requests are released.
- Blocks and unblocks only when the number of active requests goes from 0 to 1 or back to 0. Unblocking waits a few seconds (`--release-delay`), because browsers send short bursts of requests when a video starts.
- Pauses X blanking with `XScreenSaverSuspend`, the same mechanism mpv uses, instead of changing `xset` settings. The X server ends the pause by itself if the daemon exits or crashes.
- Requests whose reason is on an ignore list (default: `Playing audio`) are accepted and logged, but don't block locking. Firefox-based browsers send one for audio playback, which would otherwise keep the screen unlocked while music plays with nobody at the computer.
- Keeps the requests it holds in `$XDG_RUNTIME_DIR/xidle-inhibit.json`, so a restarted or crashed daemon takes them over. They are taken over only if the previous daemon stopped at most 30 seconds ago (`--restore-window`) on the same session bus, and only for clients still connected. A request released while no daemon was running can't be seen, so an old file isn't trusted.
- With xautolock, it re-enables xautolock on exit (including SIGTERM). The systemd unit also runs `xidle-inhibit --cleanup` when it stops, which does the same, as a fallback.
- `Lock` runs `xautolock -locknow`, or `loginctl lock-session` with xss-lock.
- If another program (a desktop environment) already owns `org.freedesktop.ScreenSaver`, it exits with status 2 instead of taking over.

## Requirements

- `xautolock` or `xss-lock`, already running in the session
- `python`, `python-gobject`
- `libx11`, `libxss`
- For `xidle-dim`: a compositor, such as picom

## Installation

Install [`xidle-inhibit`](https://aur.archlinux.org/packages/xidle-inhibit) from the AUR, for example with aurutils:

```
aur sync xidle-inhibit
pacman -S xidle-inhibit
```

The PKGBUILD builds the signed release tag, so import the signing key first:

```
gpg --recv-keys 7E12BC1FF3B6EDB2CD8053EB981A2B2A3BBF5514
```

Then start it from your window manager's startup, after the locker. For xmonad with xautolock:

```haskell
spawnOnce "xautolock -time 10 -locker slock -detectsleep"
spawnOnce "systemctl --user start xidle-inhibit"
```

With xss-lock, the lock timeout is the X screensaver timeout (`xset s TIMEOUT CYCLE`). This dims the screen with `xidle-dim` at 9:50 and locks at 10:00:

```haskell
spawnOnce "xset s 590 10"
spawnOnce "xss-lock -n xidle-dim -- slock"
spawnOnce "systemctl --user start xidle-inhibit"
```

Without dimming, use `xset s 600 0` and `xss-lock -- slock`. Start xss-lock from the window manager, not from a terminal: terminals like kitty run commands outside the login session, and xss-lock then ignores `loginctl lock-session`.

The unit has no `[Install]` section on purpose. Enabling it at login would also start it in a desktop environment, or before X is up; starting it from the window manager limits it to that session. The user service manager needs `DISPLAY` (and `XAUTHORITY`) in its environment, which `/etc/X11/xinit/xinitrc.d/50-systemd-user.sh` sets up for `startx` sessions.

## Configuration

The backend is set in `~/.config/xidle-inhibit/config` (`$XDG_CONFIG_HOME`):

```
backend = xss-lock
```

Values are `xautolock` and `xss-lock`. Without the file, xidle-inhibit uses whichever of the two is installed, and xautolock if both are. Restart the service after changing it.

## Usage

```
xidle-inhibit [-i REASON] [--count-all] [-d SECONDS] [--restore-window SECONDS] [--cleanup]
```

- `-i`, `--ignore-reason REASON`: request reason that doesn't block locking. Can be repeated; replaces the default (`Playing audio`).
- `--count-all`: every request blocks locking; no reasons are ignored.
- `-d`, `--release-delay SECONDS`: wait this long after the last release before unblocking locking (default 5).
- `--restore-window SECONDS`: take over requests from a previous daemon that stopped at most this long ago (default 30; 0 disables).
- `--cleanup`: run `xautolock -enable` if xautolock is the backend, then exit. Used by the unit's `ExecStopPost`.

To change the options used by the service:

```
systemctl --user edit xidle-inhibit.service
```

```ini
[Service]
ExecStart=
ExecStart=/usr/bin/xidle-inhibit --count-all
```

Every request, release and locker command is logged to the journal:

```
journalctl --user -u xidle-inhibit
```

### Dimming before the lock

`xidle-dim` is an xss-lock notifier (`-n`). It fades a black window over the screen until xss-lock stops it, on user activity or when the locker starts. It needs a compositor such as picom and does nothing without one. Because it doesn't change gamma, it works alongside redshift.

```
xidle-dim [--opacity 0-1] [--fade SECONDS]
```

- `--opacity`: final darkness (default 0.6).
- `--fade`: fade-in time (default 1.5).

Options go inside the notifier command: `xss-lock -n "xidle-dim --opacity 0.8" -- slock`.

## App notes

- **Sandboxed apps** may be blocked from reaching the service. For a firejail profile that filters D-Bus (`dbus-user filter`, as the Firefox-based profiles do), allow it in the app's `.local` file, e.g. `zen-browser.local`:

  ```
  dbus-user.talk org.freedesktop.ScreenSaver
  ```

- **Games**: Steam's overlay and gamemode (`inhibit_screensaver=1`) send requests on their own.
- **scrcpy** only sends a request when started with `--disable-screensaver`.
- **mpv** talks to the X server directly and doesn't need this daemon.

## Limitations

- A release sent while the daemon is down is lost: if the daemon is back within `--restore-window`, that request stays active until its app exits. After a longer stop, all held requests are dropped and apps don't send them again.
- With xss-lock, requests block only the idle timeout: suspending, or `loginctl lock-session` from elsewhere, still locks.
- `SimulateUserActivity` is accepted but does nothing. Calls are logged once when a client starts sending them and once, with a count, after 5 minutes without any.
- `GetActive` always returns `false`.

## License

GPL-3.0-or-later. See [LICENSE](LICENSE).