Step 6.2 Complete — Museum Gallery reference exhibit and Contract 5.3 spec

2026-09-14 14:09:13 -07:00
parent 961919e017
commit 44f2ad3ee6
20 changed files with 5672 additions and 8 deletions
@@ -0,0 +1,76 @@
+/*
+ * Museum Gallery — Artifact Display boot (non-primary surface).
+ *
+ * This document deliberately never loads contract-core.js, exhibit.js, or
+ * contract-adapter.js. It has no way to construct an Exhibit State Core --
+ * it can only attach to the one the Control Room document created, over
+ * surface-bus.js. If the Control Room is not open, this degrades to a clear
+ * waiting state rather than inventing its own state (Contract 5.3 Section
+ * 31.8, Step 6.1 Section 7.2).
+ */
+(function () {
+  'use strict';
+
+  var Shell = window.XZBTShell;
+  var el = Shell.el;
+  var statusEl = el('status');
+  var announcer = new Shell.Announcer({ node: el('announcement'), idleText: 'Waiting for shared state.' });
+  var cycleButton = el('cycle-button');
+
+  var ARTIFACT_ORDER = ['the-orrery', 'star-map', 'meteorite'];
+  var ARTIFACT_LABELS = { 'the-orrery': 'The Orrery', 'star-map': 'Star Map', meteorite: 'Meteorite Fragment' };
+
+  /* This is a read-only MIRROR of authoritative state, not a second copy of
+   * exhibit state: it is discarded and re-seeded from a fresh snapshot on
+   * every attach, and every write attempt is a mutate() call routed back
+   * through the owner's canonical mutation path -- this document never
+   * writes to `latest` in response to a user action, only in response to
+   * a snapshot or an event relayed from the one Core. */
+  var latest = null;
+
+  function render() {
+    if (!latest) return;
+    Shell.setText(el('artifact-name'), ARTIFACT_LABELS[latest['artifact.selected']] || latest['artifact.selected']);
+    Shell.setText(el('lighting-readout'), Shell.formatPercent(latest['lighting.level']));
+    Shell.setText(el('rotation-readout'), latest['rotation.speed'].toFixed(1) + 'x');
+  }
+
+  var link = window.MuseumGallerySurfaceBus.attach({
+    timeoutMs: 1500,
+    onSnapshot: function (snapshot) {
+      latest = snapshot.values;
+      Shell.setText(statusEl, 'Attached to Control Room.');
+      statusEl.classList.remove('is-waiting');
+      cycleButton.disabled = false;
+      render();
+    },
+    onEvent: function (event) {
+      if (!latest) return;
+      if (event.type === 'state.changed' || event.type === 'selection.changed') {
+        latest[event.target] = event.value;
+        render();
+      } else if (event.type === 'action.executed' && event.target === 'action.spotlight-flash') {
+        announcer.flash('Spotlight flashed.');
+      }
+    },
+    onTimeout: function () {
+      Shell.setText(statusEl, 'Waiting for the Control Room surface to be open…');
+      statusEl.classList.add('is-waiting');
+      cycleButton.disabled = true;
+    }
+  });
+
+  cycleButton.addEventListener('click', function () {
+    if (!latest) return;
+    var idx = ARTIFACT_ORDER.indexOf(latest['artifact.selected']);
+    var next = ARTIFACT_ORDER[(idx + 1) % ARTIFACT_ORDER.length];
+    /* Routed to the owner's canonical mutation path -- this is the required
+     * proof that a native interaction on a non-primary surface obeys the
+     * same mutation/revision/source/event semantics as primary UI or a
+     * contract set/invoke (Contract 5.3 Section 31.7). */
+    link.mutate('set', 'artifact.selected', next);
+  });
+
+  window.addEventListener('beforeunload', function () { link.detach(); });
+  window.__museumGalleryDebug = { link: link };
+})();