Struct DirectoryListingMode 

pub struct DirectoryListingMode;

The shared presentation minor. See the module docs.

Implementations

impl DirectoryListingMode

pub fn mode_id() -> ModeId

Trait Implementations

impl Mode for DirectoryListingMode

fn activation_policy(&self) -> ActivationPolicy

Both listing majors, and nothing else.

fn options(&self) -> OptionOverrideSet

What a listing pane needs from the generic render path.

These are options, not kind checks — which is what lets the shared compose path render a listing without a match buffer_kind. A regular Document with these settings renders identically, and that is the test the convergence has to pass (DL.4/DL.5).

ReadOnly is deliberately absent: it is per-major (the tree is read-only, oil is not), so it stays with the majors.

Number is absent for exactly the same reason (2026-08-16). A file tree is a navigation surface and hides line numbers, like every tree UI; oil is an ordinary editable buffer where 3dd over three files genuinely wants a count, and it is the only editable buffer in the editor that would otherwise have no gutter. Sharing one answer forced the wrong one on one of them, so the override moved to file-tree-mode.

type Guard = ()

Owned cleanup token returned by [Self::on_activate].

fn id(&self) -> ModeId

Canonical identity. Same value every call.

fn kind(&self) -> ModeKind

Major or minor. Read at registration and on every activation call (activate_major on a minor, or vice versa, is [ModeActivationError::WrongKind]).

fn required_capabilities(&self) -> CapabilitySet

Capabilities the mode requires. Validated at activation; missing capability ⇒ [ModeActivationError::MissingCapability], never silent skip.

fn on_activate(&self, ctx: ModeContext) -> LifecycleFuture<'_, ()>

Lifecycle. Called once per (buffer, activation) cycle after the registry has applied the declarative contributions. Returns an owned Guard carrying every resource the mode allocated. The dispatcher stashes the Guard until deactivation, at which point dropping it performs cleanup via the Guard’s Drop impl.

fn target_buffer_kind(&self) -> Option<BufferKind>

For major modes, the [BufferKind] this mode is the default major for (H.2, 2026-05-31). ModeRegistry::register indexes this so ModeRegistry::find_major_for_kind can dispatch buffer-creation events to the right major without host-side match BufferKind { ... } blocks.

fn target_language(&self) -> Option<&str>

For major modes, the language this mode is the default major for, by canonical name (Lang::name() — "rust", "org") (OM.1). The peer of target_buffer_kind for the dispatch path [BufferKind::Document] takes: language detection rather than kind dispatch.

fn keymap(&self) -> Keymap

Keymap chord → command additions / overrides.

fn decorations(&self) -> Vec<DecorationProvider>

Decoration providers (gutter / inline / overlay / statusline). Stub — reserved for the WIT plugin path (M.10).

fn gutter_decorations(&self, _ctx: &DecorationCtx<'_>) -> Vec<GutterDecoration>

Gutter sign decorations this mode contributes while active. Called once per pane per frame with a [DecorationCtx] carrying relevant render-state snapshots (diff sign map, LSP diagnostics arc). Returns per-line GutterDecoration values; the renderer partitions them by variant into the appropriate gutter column. Default: empty (no contribution).

fn completion_sources(&self) -> Vec<CompletionSourceContribution>

Insert-mode completion sources this mode contributes while active on a buffer. Empty by default; minors that own a completion source (lsp-completion-mode, snippet-completion-mode, buffer-words-mode, tree-sitter-completion-mode, path-completion-mode, plugin sources) override.

fn action_handlers(&self) -> Vec<ActionHandlerContribution>

Global (buffer-agnostic) action handlers this mode contributes (SN.3c.0). The host walks every registered mode’s action_handlers() once at boot, resolves each action_name → CommandId, registers the handler in the ActionHandlerRegistry, and holds the tokens for the app’s lifetime. Use this for handlers that read the active buffer / cursor / services from the ActionContext at call time and close over no per-buffer state (e.g. snippet expand). Per-buffer, session-scoped handlers register in on_activate instead, so their tokens drop with the Guard. Default: none. See feedback_effect_vocabulary_is_host_boundary.

fn conflicts_with(&self) -> &[ModeId]

Modes this one cannot be active alongside.

fn implies(&self) -> &[ModeId]

Minor modes activating this mode also activates. Used by relative-line-numbers-mode ⇒ line-numbers-mode, and by read-only majors ⇒ read-only-mode.

fn presents_extensions(&self) -> &[&'static str]

File extensions (lowercase, no dot) this major PRESENTS rather than edits — the file is never loaded as text.

fn mirrors_option(&self) -> Option<&'static str>

Declarative mirror hint for “this mode is the on/off switch for a typed option of the same observable state”. Some(canonical_name) ⇒ a host-driven cascade keeps the mode’s active state and the option’s value in sync.

fn invocation_runner(&self) -> Option<ModeId>

Invocation-runner discovery (2026-05-26). Modes that own command-invocation dispatch for their buffer kind (terminal-mode, oil-mode, file-tree-mode, help-mode, …) return their canonical [ModeId]; the host registers a runner function under that id at boot, and Editor::run_invocation looks it up by walking the active modes on the active pane’s buffer (minors first, then major) before falling back to the central grammar Action gate.

fn refresh_action(&self) -> Option<&'static str>

Which of this mode’s own actions refreshes its view, or None (the default) when the mode backs nothing refreshable (RV.1, 2026-08-10).

fn fold_toggle_action(&self) -> Option<&'static str>

Which of this mode’s actions <Tab> fires, and the declaration that pulls in foldable-view-mode — the shared minor owning the chord.

fn refresh_on_open(&self) -> bool

Should re-opening this view re-run its refresh?

fn editable_tail(&self) -> Option<EditableTail>

The mode’s editable tail on an otherwise read-only buffer, or None (the default) for a fully read-only / fully writable buffer (AU‑3).