Kokkoja as of 2026-10-10: the teacher's requests, the Session window, notices, the QR code, the license

client/js/log.js

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+// @ts-check
+/**
+ * A record of the singular events of a session in the browser's console
+ * (F12), for finding faults: pages, images, notebook pages, exports, the
+ * co-host right, the connection, and what the input device delivers.
+ * Nothing continuous goes here (Andy, 2026-10-08).
+ *
+ * Since 2026-10-10 the same record, plus a trace of the input events
+ * (every press, release and cancellation, not the movement between), is
+ * kept in memory and shown in the Session window with a Copy button, so
+ * that a guest on a tablet, with no console to open, can send it when
+ * the pen misbehaves (Andy's iPad, where the Pencil stopped for a while
+ * now and then).
+ */
+
+/** How many entries are kept; the oldest go first. */
+const KEPT = 400;
+
+/** @type {string[]} */
+const entries = [];
+/** @type {(() => void) | null}  Told of every new entry. */
+let listener = null;
+
+/** @returns {string}  The time to the millisecond, HH:MM:SS.mmm. */
+function now() {
+  const date = new Date();
+  const two = (/** @type {number} */ n) => String(n).padStart(2, '0');
+  return `${two(date.getHours())}:${two(date.getMinutes())}:${two(date.getSeconds())}.` +
+         String(date.getMilliseconds()).padStart(3, '0');
+}
+
+/** @param {string} what */
+function keep(what) {
+  entries.push(`${now()} ${what}`);
+  if (entries.length > KEPT) entries.shift();
+  listener?.();
+}
+
+/** A singular event: the console and the record. @param {string} what */
+export function log(what) {
+  console.log(`Kokkoja ${new Date().toLocaleTimeString()}: ${what}`);
+  keep(what);
+}
+
+/** An input event: the record only. @param {string} what */
+export function trace(what) {
+  keep(what);
+}
+
+/** @returns {string}  The record, one entry a line. */
+export function logText() {
+  return entries.join('\n');
+}
+
+/** @param {(() => void) | null} onEntry  Called at every new entry. */
+export function watchLog(onEntry) {
+  listener = onEntry;
+}