Struct MagitHunkMode 

pub struct MagitHunkMode;

Implementations

impl MagitHunkMode

pub fn mode_id() -> ModeId

Trait Implementations

impl Mode for MagitHunkMode

type Guard = MagitHunkGuard

MG.45: carries the diff-fold registration. Every ACTION this mode binds is still registered once at boot by the mode that owns its body (magit-core-mode for the shared hunk machinery, magit-status-mode’s actions.rs for discard’s ask/execute pair) — this mode contributes bindings, not handlers.

fn activation_policy(&self) -> ActivationPolicy

The five majors that render unified diff — and only those.

Deliberately NOT the list magit-core-mode carries. A branch list, a log, a stash list, a rebase todo, a blame and a blob have no hunks, so binding s/u/x/]c there would consume the keys to do nothing. That is the state ]c and a/- were already in before this mode existed.

fn options(&self) -> OptionOverrideSet

MG.46: the diff text folds by hunk, never by code structure.

This mode owns what is inside the diff, so it owns which folds may exist there. foldmethod=manual leaves ManualPrimary — which produces nothing — as the primary, so the only folds are this mode’s own file ▸ hunk overlays plus magit-status’s entry overlay.

Without it, a user whose global foldmethod is indent or syntax gets the primary provider run over the diff as if it were source. It is not: a hunk is a fragment with +/-/ prefixes on every row, so the folds it derives are structurally meaningless — and the last one, opened by an indent that the fragment never closes, runs to the end of the buffer and swallows the rest of the magit-status document.

Scoped to the mode rather than the buffer kind: the override reverts when the mode deactivates, and it reaches exactly the five diff-rendering majors this mode activates on.

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

MG.45: register the file ▸ hunk fold source.

Registered HERE rather than per major because this mode already activates on exactly the buffers that render a diff — which is what makes one source serve five majors instead of five near-copies. magit-status keeps its own source for the ENTRY level; the two compose by range containment.

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 keymap(&self) -> Keymap

Keymap chord → command additions / overrides.

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 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 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 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).