`read_window_below` enumerates through get-windows, which on Linux reads
`_NET_CLIENT_LIST_STACKING` via xprop. That is an X11 protocol, and Wayland
deliberately refuses to tell one application about another's windows. Under
XWayland it is worse than nothing: it finds the few legacy X11 clients and
silently misses every native Wayland window, which on a Hyprland desktop is
most of them — so the HUD floats over an app it cannot name.
Hyprland answers the question directly. `j/clients` on its command socket
returns every window with class, title, position, size, pid and focus history.
Ask it first when HYPRLAND_INSTANCE_SIGNATURE is set, fall back to get-windows
everywhere else, and keep the picking logic shared and unchanged.
Three things the provider has to get right, all covered by tests: order comes
from focusHistoryID rather than the list; windows on other workspaces are
dropped, since they share coordinates with the visible ones and would win the
overlap test; and our own window is left out, because focus history is not
stacking order — the HUD floats on top while the user works underneath it, so
slicing after ourselves would skip past the very app we are trying to report.
One request per tool call, opened and closed immediately: Hyprland evaluates
this socket synchronously and freezes until a five-second timeout on a
connection left hanging.
When enumeration was impossible the tool answered "could not determine the
window underneath (the desktop app did not answer, or window enumeration is
unavailable on this system)" — true, and a dead end. On Linux the two ways it
fails have opposite fixes and neither is guessable from that: a Wayland session
withholds window identity from applications outright, while an X11 session
needs xprop and xwininfo installed, because that is what the enumerator shells
out to.
Answer with the reason instead of nothing. A session with both WAYLAND_DISPLAY
and DISPLAY is XWayland, where xprop can still answer, so it gets the tooling
advice rather than being told to change session type.
The desktop_ui and post-hook ownership contract tests enumerate their tool
sets exactly — add read_window_below to both (plus the executor-path
parametrize case). Lint: sorted type import, explicit GetWindowsModule type
instead of an import() annotation, curly + blank-line style.
New electron/window-below.ts: pure z-order picker (walks past our own pid,
first other-process window whose bounds overlap ours) over get-windows'
front-to-back enumeration, with the Linux xprop stacking order reversed to
match (EWMH _NET_CLIENT_LIST_STACKING is bottom-to-top). Main answers the
hermes🪟readBelow IPC; on macOS other apps' titles pass through only
when Screen Recording is already granted — never prompted for.
brooklyn!
hermes-seaeye[bot]