Why does DropTerm show up in the window switcher and dock — and what can remove it?

Date: 2026-10-24

TL;DR

The app’s own surfaces never appear in the switcher or dock — its clipboard anchor does. The anchor is a 1×1 xdg toplevel that winit cannot unmap on Wayland, and COSMIC’s toplevel-info protocol exists to list exactly those windows to “clients such as taskbars or docks”. No protocol request can hide a toplevel from those listings, so the fix is to make the anchor a layer surface — a window kind the listing protocols structurally cannot see — selected by a show_in_dock key whose true keeps today’s dock presence. Verdict shipped as the shell-presence pass.

Findings (read from the vendored sources, 2026-10-24)

  1. The anchor is a mapped toplevel by construction. src/app.rs’s clipboard_anchor_settings opens a 1×1 window::open toplevel with visible: false — but the pop-os winit fork’s Wayland backend implements set_visible as a literal no-op (winit-wayland/src/window/mod.rs:397: “Not possible on Wayland”), so the toplevel is mapped for the whole process lifetime. winit at 0.31.0-beta.2, rev 9567503 per Cargo.lock.

  2. The listings are toplevel-only, by protocol. COSMIC’s zcosmic_toplevel_info_unstable_v1 describes itself as serving “clients such as taskbars or docks” that need “a list of opened applications” — and its objects are xdg toplevels (ext_foreign_toplevel_v1 extended). Layer surfaces have no entry anywhere in it. The companion zcosmic_toplevel_management_v1 offers no skip request either: its full request set is destroy, close, activate, set/unset_maximized, set/unset_minimized, set/unset_fullscreen, set_rectangle (read from the cosmic-protocols checkout at c0cff4d). An SNI/status-notifier icon is a different mechanism entirely — a presence added, never one removed.

  3. Why the anchor exists at all — the clipboard binding. iced’s runtime keeps one app-wide Clipboard (iced/winit/src/clipboard.rs): it is bound via Clipboard::connect(first window) and reset to unconnected only when the window it holds is removed from the window manager (three destroy paths in iced/winit/src/platform_specific/wayland/sctk_event.rs:740,957,1703 all guard clipboard.window_id() … w.raw.id() == id before resetting). Any never-destroyed window therefore keeps the binding — and the copied selection — alive across every hide.

  4. A layer surface can be the anchor. The connect sites are not toplevel-only: sctk_event.rs:1009 and :1247 bind the clipboard to layer-surface windows as they are created (the guard is clipboard.window_id().is_none() — first window of any kind wins). So a layer-surface anchor created before the terminal’s own surface owns the binding identically.

  5. A layer surface can be made inert. SctkLayerSurfaceSettings.input_zone is applied by the runtime (iced/winit/src/platform_specific/wayland/event_loop/state.rs creates a compositor region, adds each rectangle, then wl_surface.set_input_region) — so Some(vec![]) is an empty input region: no pointer events at all. With keyboard_interactivity: None, a 1×1 Bottom-layer surface with exclusive_zone: -1 neither paints over anything, takes input, nor claims space.

What DropTerm had today (the 2026-10-24 snapshot)

The xdg anchor with its app-id pin — correct on its own terms (the switcher entry at least carried DropTerm’s name and icon instead of “unknown”), and the ROADMAP’s v1 promise “Hidden from Alt-Tab and dock” had been silently broken by the anchor’s arrival. The maintainer filed it as the bug row “app is not hidden from alt tab” and asked for configurability keyed to the panel applet.

Recommendation (shipped)

Give the anchor two bodies behind show_in_dock (default false): the hidden body is surface::anchor — the layer surface of finding 5, namespaced <app id>.anchor so no namespace-keyed shell rule matches it; the dock body is today’s toplevel. A flip swaps them live, destroy-before-create so the new body’s creation event rebinds the clipboard immediately (finding 3’s reset only fires on removal); the selection on the clipboard dies once per flip — the documented cost. The panel applet — the v3 record’s out-of-process handle — is the persistent summon path in hidden mode and needs nothing new.

Rejected alternatives:

Sources

Improve this page on GitHub