// One page at a time. Sites, You, Fronts, Rogues, Paper, the tree and the Select list sit in the same spot
// over the map, so a page that opens closes whichever other one is open. Screen state only: no rules here.
const pages = new Map<string, () => void>();
/** A page's way to close itself without telling the others (its flag, and nothing more). */
export function onePage(name: string, close: () => void) { pages.set(name, close); }
/** `name` is opening: close every other page. */
export function opening(name: string) { for (const [k, close] of pages) if (k !== name) close(); }