Trait ThemeRegistry 

pub trait ThemeRegistry: Send + Sync {
    // Required methods
    fn register(
        &self,
        name: ElementName,
        owner: ElementOwner,
        default: StyleSpec,
        doc: &'static str,
    ) -> ElementId;
    fn id(&self, name: &ElementName) -> Option<ElementId>;
    fn resolved(&self) -> Arc<ResolvedTheme> ;
    fn set_override(&self, name: ElementName, spec: StyleSpec);
    fn set_theme(
        &self,
        palette: Palette,
        overrides: Vec<(ElementName, StyleSpec)>,
    );
    fn describe(&self, name: &ElementName) -> Option<ElementInfo>;
    fn element_names(&self) -> Vec<String>;
    fn unregister_element(&self, name: &ElementName) -> bool;
    fn register_theme(&self, theme: NamedTheme);
    fn theme_names(&self) -> Vec<String>;
    fn apply_theme(&self, name: &str) -> bool;
    fn active_theme(&self) -> (Palette, Vec<(ElementName, StyleSpec)>);
}

Registration + resolution surface. Lives as a ServiceRegistry service (T.3); modes reach it through the handle, never through &mut Editor.

Required Methods

fn register( &self, name: ElementName, owner: ElementOwner, default: StyleSpec, doc: &'static str, ) -> ElementId

Register an element with its owner-supplied default. Idempotent by name — re-registering an existing name returns the existing id and leaves its default unchanged.

fn id(&self, name: &ElementName) -> Option<ElementId>

The interned id for a name, if registered.

fn resolved(&self) -> Arc<ResolvedTheme>

The current resolved read table (rebuilt lazily if a registration / palette change left it dirty).

fn set_override(&self, name: ElementName, spec: StyleSpec)

T.9: set (or replace) the theme-global override for an element (:set ui.*, user TOML, a theme’s override list). Overlays the override’s set fields on the element’s resolved default. Marks the table dirty (re-resolved on next resolved()).

fn set_theme(&self, palette: Palette, overrides: Vec<(ElementName, StyleSpec)>)

T.9: swap the active theme — replace the palette AND the full override set atomically (:colorscheme). Prior overrides are cleared. Marks the table dirty.

fn describe(&self, name: &ElementName) -> Option<ElementInfo>

T.9.d: element metadata for introspection (:describe-element / :describe-face). Returns the element’s identity + owner + authoring default + doc + concrete resolved style, or None if name is not a registered element. Reads the resolved table (rebuilding it lazily if dirty) so the resolved field reflects the active theme — a theme-build-time read, never on the hot path.

fn element_names(&self) -> Vec<String>

T.9.d follow-up: the names of every registered theme element, sorted. Drives :describe-element / :describe-face <Tab> completion (the gen:elements host generator). Sorted so popup ordering is stable across runs; a theme-build-time read, never on the hot path.

fn unregister_element(&self, name: &ElementName) -> bool

TC.4: withdraw an element by name — the reverse of Self::register, used when a plugin unloads. Returns whether a name was removed (idempotent: a second unload removes nothing).

The slot is tombstoned, not deleted. ElementId is an index into the element vector, so removing an entry would silently re-point every later id at the wrong element — a far worse failure than a retained slot. Withdrawing therefore drops the NAME binding only: id, describe and element_names all resolve through by_name, so the element disappears from every observable surface (lookup, :customize, :describe-element) while ids already handed out stay valid and keep resolving to their last style.

Any theme override the user set for the name is left in place: a plugin reload should not silently discard the user’s customisation, and a dangling override for an element that never comes back resolves to nothing.

fn register_theme(&self, theme: NamedTheme)

T.11.1: register (or replace, by name) a named theme in the catalog. Idempotent by name — re-registering a name replaces its palette + overrides. This is the seam init.rs (and, later, a WASM plugin via WIT) uses to contribute a palette; the builtin themes are seeded here at boot. Does NOT change the active theme — only apply_theme does that.

fn theme_names(&self) -> Vec<String>

T.11.1: the names of every registered theme, in registration order (builtins first, then user/plugin additions). Drives :colorscheme completion + the T.12 picker.

fn apply_theme(&self, name: &str) -> bool

T.11.1: swap the active theme to the registered theme name (:colorscheme <name>). Returns false (active theme untouched) if name is not registered — the caller echoes an error, never a panic. On a hit, equivalent to set_theme with the registered theme’s palette + overrides (marks the table dirty).

fn active_theme(&self) -> (Palette, Vec<(ElementName, StyleSpec)>)

T.12a: snapshot the active palette + the active theme-global override set as a (Palette, Vec<(ElementName, StyleSpec)>) pair. The colorscheme picker captures this on the first live preview so <Esc> can restore the theme active when the picker opened via Self::set_theme. Cheap clone of the inner state under a read lock; no resolution.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl ThemeRegistry for InMemoryThemeRegistry