wl-pick

A window switcher for wlroots compositors: a grid of live window previews that prints which one you picked. It doubles as a screencast source picker for the desktop portal.

No thumbnails are ever made. Each window is captured straight into a buffer handed to its own subsurface and the compositor does the scaling, so wl-pick appears in about 60 ms and sits around 6 MB resident however many windows are open. There is a longer write-up of why it works this way in wl-pick: a live window picker for Sway.

Install

cargo install wl-pick

Usage

wl-pick is a chooser: the pick goes to stdout, nothing does if you cancel, and it never acts on the choice itself. Exit status is 0 for a pick, 1 for anything else, and 2 if --timeout fires.

#!/usr/bin/env bash
# save as a script and bind it to $mod+Tab
IFS=$'\t' read -r type id toplevel app title < <(wl-pick) || exit 0
case $type in
    window) swaymsg "[con_id=$id] focus" ;;
    output) swaymsg "focus output $id" ;;
esac

Arrows, hjkl or Tab/Shift+Tab move, PgUp/PgDn and Home/End jump, Enter picks and Escape or q cancels; clicking a tile picks it. wl-pick --help lists the flags.

Output formats

Different consumers need different identifiers, so --format offers three. tsv, the default, prints TYPE⇥ID⇥TOPLEVEL_ID⇥APP⇥TITLE, where ID is the sway con_id or an output name; json prints the same fields for jq; and portal prints Monitor: NAME or Window: TOPLEVEL_ID.

That last one is exactly what xdg-desktop-portal-wlr's simple chooser reads, so wl-pick can be the picker for getDisplayMedia and friends:

[screencast]
chooser_type=simple
chooser_cmd=wl-pick --format portal

Config

~/.config/wl-pick/config, or --config PATH. Flat key = value lines with # comments, everything optional, and a flag always beats the file. --help lists every key; the ones worth explaining are the sizes.

max-width      = 90ppt        # the box the grid may fill
max-height     = 90ppt
max-columns    = 4            # thumbnails are that box divided by these
max-rows       = 4

600px is absolute and 90ppt a percentage of the display the grid appears on, worked out afresh each run, so one file suits a 1280-wide laptop panel and a 3840-wide monitor alike. All four are caps: the first two bound the overlay, the last two bound the grid inside it, and a thumbnail is simply the one divided by the other. A thumbnail is therefore the same size whether one window is open or thirty — the overlay just hugs whatever is there. Rows past max-rows scroll.

Requirements

A wlroots compositor advertising ext-image-copy-capture-v1, ext-image-capture-source-v1, ext-foreign-toplevel-list-v1, wlr-layer-shell-unstable-v1 and wp_viewporter. In practice that means sway 1.12+: 1.11 could capture whole outputs, and 1.12 extended that to individual windows, which is what the previews are. sway's IPC socket is also the source of truth for the window list. Hyprland, labwc and jay advertise the protocols but are untested.

Known upstream issue: holding per-toplevel capture sessions open makes windows blurry on fractionally scaled outputs (sway#9113). Integer scales are unaffected, and --live none avoids it.

Notes

• Starting a second wl-pick replaces the first: the new overlay takes the keyboard and the old one exits without printing anything.
• Navigation reads raw evdev keycodes, so it is layout-independent — but virtual-keyboard clients such as wtype cannot drive it.
• The sway socket comes from SWAYSOCK/I3SOCK when those point at something real, and from the running sway otherwise, since inheriting a stale path is easy.

Building

cargo build --release
cargo test