Crate wl_probe 

A Wayland client that asks the compositor questions and prints the answers.

Solium cannot test its own protocol support from the inside, and “the global is advertised” is a different claim from “a client that uses it gets the right answers back”. The difference has been the whole story of a week of protocol work: a cursor that was advertised and invisible, a relative pointer that was advertised and correct, a lock that was granted too early to be heard.

Real applications were borrowed for that verification — Firefox’s own WAYLAND_DEBUG log is a fine oracle — and it works right up until no installed application happens to use the protocol you just added. Firefox never binds wp_presentation, so nothing on this machine could tell whether presentation feedback worked at all. This is that gap, filled.

cargo run -p wl-probe

It maps one small window, waits for a few frames, and reports what came back. Exit status is zero only if every check passed, so it can be a gate.

Structs

Presented 🔒

Probe 🔒

Screen 🔒

One wl_output, as a client learns about it.

Shot 🔒

A screen capture in progress.

Constants

BAR 🔒

How tall a probe bar is, and how much of the screen it reserves.

FRAMES 🔒

How many frames to ask about before reporting.

Functions

anchor_a_bar 🔒

Anchor a bar to the top of every monitor and check where each one landed.

layouts_in_keymap 🔒

Read the keymap the compositor sent and pull the layout names out of it.

layouts_in_keymap_text 🔒

The layout names a keymap declares, in group order.

lock_the_session 🔒

Lock the session, hold it, and let it go.

main 🔒

map_and_measure 🔒

Put a window up, ask about FRAMES frames, and check the answers.

screen_pixels 🔒

The first output’s width in device pixels.

settle 🔒

Flush, wait for the compositor to answer, dispatch whatever arrived.

show_popup 🔒

WL_PROBE_POPUP=<seconds>: a 520x360 toplevel in the window colour and a 160x120 popup in the menu colour, anchored 20 px inside its bottom-right corner so it reaches past it.

show_windows 🔒

Map two windows – one decorated by the compositor, one not – and hold them up to be looked at.

solid_buffer 🔒

A buffer with something in it, so the compositor has a frame to present.

take_a_shot 🔒

Ask for a screenshot, and look at it.

tempfile 🔒

An anonymous file of size bytes, filled with an opaque colour.

tempfile_rs 🔒

tinted_buffer 🔒

The same, in a colour of the caller’s choosing.

watch_idle 🔒

Go idle, be held awake, and go idle again.

watch_keyboard 🔒

Map a window, take focus, and report every layout change that arrives.

write_ppm 🔒

Write a captured buffer out as a binary PPM, so a person can look at it.