enum DesktopSettings

Whether there is a compositor to ask. False in a windowed app, where none of this exists and the panel should say so rather than show controls that do nothing.

The desktop's corner radius and the shadow it puts under a window.

"extend" or "mirror".

Every shortcut the compositor takes before a client sees the key.

Read-only, and that is the honest shape today: the bindings are compiled in. Listing them is still worth doing — a desktop whose shortcuts can only be found by reading its source has no shortcuts, as far as most people are concerned.

Every layout and variant this machine's xkb offers.

Flat: an entry whose variant is empty is a layout, and the rest are its variants. layoutsByCode() is the grouped form, which is what a picker actually wants.

Slow enough to be worth caching — it is a parse of the whole xkb rules file, a few thousand entries — and constant for the life of the session, so it is cached here rather than in every caller.

The same list, grouped: each base layout with its variants after it, in the order xkb reports them.

Every mode a screen can run at, biggest first then fastest.

A request pre-filled from what a screen is doing now, so a caller changing one field does not have to restate the other six.

Sets both, immediately and for the next session.

Immediately is the point: these are numbers the compositor reads per frame, so every window on screen takes the new ones before this call returns. That is what makes a slider here honest — the preview is the result.

Values out of range are clamped by the compositor rather than refused; read appearance() back to see what was taken.

Extend or mirror, immediately and for the next session.

Changes the keyboard, immediately and for the next session.

wlroots hands the new keymap to every connected client as a side effect, so this reaches applications that are already running — which is the difference between this and editing the config file.

Reconfigures a screen, immediately and for the next session.

The whole state rather than one field, because applying it is one commit: a screen asked to change mode and then position would be re-laid-out twice, through an arrangement nobody asked for.

A mode the display refuses does not cost the session — the compositor falls back to the preferred one rather than leaving a screen showing nothing. Read outputs() back to find out whether what you asked for is what you got.

Makes this screen the primary: the panel moves here, and new windows open here. Empty means no preference.

Pushes the name; every subscribed Lava window retints.

Sets the desktop background, immediately and for the next session.

The only setter here that can refuse. A picture that will not decode throws WallpaperUnreadable and changes nothing — the old background is still up and still saved — which is a different report from SettingsWriteFailed, where the change is on screen and will not survive a restart. A panel that collapses the two will tell the user the wrong thing in one of the two cases.

The system colour theme name (dark / light / nebula).

What the desktop is painted with, behind every window.

Reports what is on screen. After a picture the compositor could not read, that is the background which survived — not the one that was asked for — so re-reading this after a failure is how a panel gets its controls back in step with the desktop.