cross_tab 0.1.0

Coordinate the browser tabs of a Flutter Web app: send typed messages between them, know how many are open, and elect exactly one to do the work.

0.1.0

Initial release: cross-tab coordination for Flutter Web.

• CrossTab.open(name) joins every tab of your app sharing that name.
• Leader election. Exactly one tab is elected to do work that must happen once — polling, a socket, a notification — and leadership moves when that tab closes. The oldest tab leads, with the id as a tiebreak so tabs opened in the same microsecond still reach the same answer.
• Presence. count, tabs, leader, isLeader, emitted on change and on subscription. A closed tab says goodbye so the others react immediately; a crashed one is dropped after three missed heartbeats.
• Messages with a sender id, carrying structure rather than strings. A tab never hears its own.
• Off the web the package still compiles and behaves as the single instance it is: one tab, always the leader. That is the truthful answer, and it means leader logic needs no if (kIsWeb) around it.

Verified in a real browser: flutter test --platform chrome exercises four tabs agreeing on one leader, the oldest winning, and leadership passing on close — using two BroadcastChannel objects in one document, which see each other exactly as separate tabs do.