Struct MagitProjectDiffMode 

pub struct MagitProjectDiffMode;

magit-project-diff-mode — the provider-minor activated on a project-diff view.

Declares no keymap of its own. It activates magit-core-mode alongside, which is where magit’s cross-buffer chords already live (gr, q, ]] / [[, …) — so this view inherits the family’s chords by joining the family rather than by copying them. That is the “shared behaviour is a minor mode, never a copied keymap” rule paying out in the crate where the missing-x gap happened.

Implementations

impl MagitProjectDiffMode

pub fn mode_id() -> ModeId

Trait Implementations

impl Mode for MagitProjectDiffMode

fn options(&self) -> OptionOverrideSet

Editable by default — no ReadOnly override. A read-only comparison (§2.1) sets the per-buffer read-only property at creation instead, so read-only is a property of the view, not a second mode or a renderer kind-branch.

fn keymap(&self) -> Keymap

No chords. gr / q arrive from magit-core-mode, which this mode implies.

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

Joining the magit family is what supplies the chords; declaring them here would be the duplication the standing rule forbids.

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

PD.7c: what gr actually does here.

refreshable-view-mode binds the chord and resolves it to whichever active mode declared this — so implying that mode without declaring an action, which is what PD.9 left behind, bound gr in this view to nothing at all. The comment on implies said “refreshable-view-mode supplies gr”; it supplied the binding, and there was no target.

Found while giving the headerline a “gr to refresh” note to point at, which is the only reason it surfaced — a chord that resolves to nothing produces no error, no log line and no failing test. refreshable_views_declare_their_refresh.rs now guards the class.

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

The refresh body, in the crate that owns the view — the other half of the mode-ownership rule. Re-running the provider IS the refresh: open_project_diff already clears the view and rescans (it has to, since the same view is reused across triggers), so there is no second rebuild path to keep in step with the first.

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

PD.7c: watch for edits to this view’s sources and apply the staleness policy.

The mode owns the policy because the mode owns the view — the substrate publishes the fact (MultibufferSourceEdited, with the DocumentId → source translation already done, since the source map lives there) and this decides what it means for magit’s diff data. No host involvement in either half.

type Guard = MagitProjectDiffModeGuard

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 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 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 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 activation_policy(&self) -> ActivationPolicy

A minor mode’s default auto-activation policy (MA.1; mode-architecture.md §7.4). The host’s minor-activation resolver reads this for every registered minor when a buffer enters a major mode, and activates those whose policy admits the entered major. The default is [ActivationPolicy::Manual] — auto-activate nowhere until the mode or the user opts in. Ignored for major modes (a buffer’s major is chosen by the major resolver, not this allowlist).

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).