@kbn/core-chrome-browser-hooks

Shared React hooks over the Chrome observable APIs.

Prerequisites

These hooks require ChromeServiceProvider to be present in the React tree. Core sets this up automatically — any component rendered via rendering.addContext(element) has access to all hooks in this package.

Entry points

Public (@kbn/core-chrome-browser-hooks)

For use by plugins and any code outside core Chrome internals:

• useChromeStyle() — returns the current ChromeStyle ('classic' or 'project'). Defaults to 'classic' until explicitly changed.
• useActiveSolutionNavId() — returns the active solution nav ID, or null when no solution nav is active.
• useIsChromeVisible() — returns true when the chrome UI (header and navigation) is currently visible.
• useSidebarWidth() — returns the effective sidebar pixel width (0 when the sidebar is closed).

Internal (@kbn/core-chrome-browser-hooks/internal)

For use by core Chrome components only (e.g. layout, grid). Not part of the public API:

• useGlobalFooter() — returns the current global footer ReactNode (used by the developer toolbar).
• useHasHeaderBanner() — returns true when a header banner is currently registered via chrome.setHeaderBanner().

Notes

Hooks intentionally do not take caller-provided default values. They seed state from synchronous Chrome getters to match current chrome state before subscribing to observables.

All hooks consume useChromeService() from @kbn/core-chrome-browser-context, which returns InternalChromeStart — the full internal chrome API injected by core through chrome.withProvider(...). Public hooks only use the ChromeStart subset; internal hooks may access internal-only APIs such as getGlobalFooter$().