feat(pad): scrub history in-place on the pad URL (#7659)

doc/skins.adoc

@@ -6,11 +6,18 @@ A skin is a directory located under `static/skins/<skin_name>`, with the followi
 * `index.css`: stylesheet affecting `/`
 * `pad.js`: javascript that will be run in `/p/:padid`
 * `pad.css`: stylesheet affecting `/p/:padid`
-* `timeslider.js`: javascript that will be run in `/p/:padid/timeslider`
-* `timeslider.css`: stylesheet affecting `/p/:padid/timeslider`
+* `timeslider.js`: javascript that will be run in the embedded timeslider iframe
+* `timeslider.css`: stylesheet affecting the embedded timeslider iframe
 * `favicon.ico`: overrides the default favicon
 * `robots.txt`: overrides the default `robots.txt`
 
+Since Etherpad *2.7*, the timeslider is rendered in-place inside the pad
+page (issue #7659). Direct visits to `/p/:padid/timeslider` 302-redirect to
+`/p/:padid` so the in-pad `PadModeController` can take over via a `#rev/N`
+URL hash. The full timeslider HTML is still served at
+`/p/:padid/timeslider?embed=1` -- that is the URL the in-pad iframe loads,
+and the URL to use if you embed the timeslider in your own page.
+
 You can choose a skin changing the parameter `skinName` in `settings.json`.
 
 Since Etherpad **1.7.5**, two skins are included:

doc/skins.md

@@ -6,8 +6,15 @@ A skin is a directory located under `static/skins/<skin_name>`, with the followi
 * `index.css`: stylesheet affecting `/`
 * `pad.js`: javascript that will be run in `/p/:padid`
 * `pad.css`: stylesheet affecting `/p/:padid`
-* `timeslider.js`: javascript that will be run in `/p/:padid/timeslider`
-* `timeslider.css`: stylesheet affecting `/p/:padid/timeslider`
+* `timeslider.js`: javascript that will be run in the embedded timeslider iframe
+* `timeslider.css`: stylesheet affecting the embedded timeslider iframe
+
+Since Etherpad **2.7**, the timeslider is rendered in-place inside the pad
+page (issue #7659). Direct visits to `/p/:padid/timeslider` 302-redirect to
+`/p/:padid` so the in-pad PadModeController can take over via a `#rev/N`
+URL hash. The full timeslider HTML is still served at
+`/p/:padid/timeslider?embed=1` — that is the URL the in-pad iframe loads,
+and the URL to use if you embed the timeslider in your own page.
 * `favicon.ico`: overrides the default favicon
 * `robots.txt`: overrides the default `robots.txt`
 

src/locales/en.json

@@ -234,6 +234,19 @@
   "timeslider.followContents": "Follow pad content updates",
   "timeslider.pageTitle": "{{appTitle}} Timeslider",
   "timeslider.toolbar.returnbutton": "Return to pad",
+  "pad.historyMode.banner": "Viewing history",
+  "pad.historyMode.return": "Return to live",
+  "pad.historyMode.revisionLabel": "Revision {{rev}}",
+  "pad.historyMode.controlsLabel": "Pad history controls",
+  "pad.historyMode.sliderLabel": "Pad revision",
+  "pad.historyMode.settings.title": "History playback",
+  "pad.historyMode.settings.follow": "Follow pad content updates",
+  "pad.historyMode.settings.followShort": "Follow",
+  "pad.historyMode.followOn": "Following pad changes — click to stop following",
+  "pad.historyMode.followOff": "Not following pad changes — click to follow",
+  "pad.historyMode.settings.playbackSpeed": "Playback speed:",
+  "pad.historyMode.chat.replayHeader": "Chat as of {{time}}",
+  "pad.historyMode.users.authorsHeader": "Authors at this revision",
   "timeslider.toolbar.authors": "Authors:",
   "timeslider.toolbar.authorsList": "No Authors",
   "timeslider.toolbar.exportlink.title": "Export",

src/node/handler/PadMessageHandler.ts

@@ -418,6 +418,12 @@ exports.handleMessage = async (socket:any, message: ClientVarMessage) => {
       padID: message.padId,
       token: resolvedToken,
     };
+    // Issue #7659: connections from the in-place history iframe must not
+    // trigger the duplicate-author kick — they share the parent's author
+    // by design, and kicking the parent on iframe load would tear down
+    // the live editor mid-session. The iframe sets `embed=1` in its
+    // socket.io handshake query.
+    thisSession.embed = socket.handshake?.query?.embed === '1';
 
     // Pad does not exist, so we need to sanitize the id
     if (!(await padManager.doesPadExist(thisSession.auth.padID))) {
@@ -1051,12 +1057,16 @@ const handleClientReady = async (socket:any, message: ClientReadyMessage) => {
   // stable identity across windows and devices, so concurrent same-author
   // sessions are legitimate and must not be kicked.
   const roomSockets = _getRoomSockets(pad.id);
-  if (user == null) {
+  if (user == null && !sessionInfo.embed) {
     for (const otherSocket of roomSockets) {
       // The user shouldn't have joined the room yet, but check anyway just in case.
       if (otherSocket.id === socket.id) continue;
       const sinfo = sessioninfos[otherSocket.id];
-      if (sinfo && sinfo.author === sessionInfo.author) {
+      // Embedded sessions (issue #7659 — in-place history iframe) share
+      // the parent's author by design, so they neither kick same-author
+      // sockets nor get kicked by them. Only non-embedded same-author
+      // duplicates (real stale tabs) hit the kick path.
+      if (sinfo && sinfo.author === sessionInfo.author && !sinfo.embed) {
         // fix user's counter, works on page refresh or if user closes browser window and then rejoins
         sessioninfos[otherSocket.id] = {};
         otherSocket.leave(sessionInfo.padId);

src/node/hooks/express/specialpages.ts

@@ -228,8 +228,14 @@ const handleLiveReload = async (args: ArgsExpressType, padString: string, timeSl
       })
 
       setRouteHandler("/p/:pad/timeslider", (req: any, res: any, next: Function) => {
+        // Direct visits (legacy bookmarks) get redirected back to the pad,
+        // where the in-pad PadModeController handles entering history mode.
+        // The iframe used by history mode requests this URL with ?embed=1
+        // and gets the full timeslider HTML rendered for embedded use.
+        if (req.query.embed !== '1') {
+          return res.redirect(302, `../${encodeURIComponent(req.params.pad)}`);
+        }
         ensureAuthorTokenCookie(req, res, settings);
-        console.log("Reloading pad")
         // The below might break for pads being rewritten
         const isReadOnly = !webaccess.userCanModify(req.params.pad, req);
 
@@ -246,6 +252,7 @@ const handleLiveReload = async (args: ArgsExpressType, padString: string, timeSl
           req,
           toolbar,
           isReadOnly,
+          embed: true,
           entrypoint: proxyPath + '/watch/timeslider?hash=' + hash,
           settings: settings.getPublicSettings(),
           socialMetaHtml,
@@ -392,6 +399,18 @@ exports.expressCreateServer = async (_hookName: string, args: ArgsExpressType, c
 
     // serve timeslider.html under /p/$padname/timeslider
     args.app.get('/p/:pad/timeslider', (req: any, res: any, next: Function) => {
+      // Direct visits (legacy bookmarks) get redirected back to the pad,
+      // where the in-pad PadModeController handles entering history mode.
+      // The iframe used by history mode requests this URL with ?embed=1
+      // and gets the full timeslider HTML rendered for embedded use.
+      if (req.query.embed !== '1') {
+        // Absolute path (not relative `../`) so Firefox and Chrome resolve
+        // it identically — relative redirects from /p/:pad/timeslider are
+        // technically well-defined but Firefox dropped a trailing-slash
+        // case once that flaked the legacy-URL test (#7710).
+        const proxyPath = sanitizeProxyPath(req);
+        return res.redirect(302, `${proxyPath}/p/${encodeURIComponent(req.params.pad)}`);
+      }
       ensureAuthorTokenCookie(req, res, settings);
       hooks.callAll('padInitToolbar', {
         toolbar,
@@ -403,6 +422,7 @@ exports.expressCreateServer = async (_hookName: string, args: ArgsExpressType, c
       res.send(eejs.require('ep_etherpad-lite/templates/timeslider.html', {
         req,
         toolbar,
+        embed: true,
         entrypoint: "../../"+fileNameTimeSlider,
         settings: settings.getPublicSettings(),
         socialMetaHtml,

src/static/css/pad.css

@@ -107,3 +107,182 @@ input {
 }
 #version-badge[data-level="severe"]   { background: #fff3cd; color: #664d03; border: 1px solid #ffe69c; }
 #version-badge[data-level="vulnerable"] { background: #f8d7da; color: #58151c; border: 1px solid #f1aeb5; }
+
+/* ----------------------------------------------------------------------- */
+/* History mode (issue #7659): timeslider rendered in-place inside the     */
+/* pad page. The live editor stays mounted but hidden; a sibling iframe    */
+/* hosts the existing timeslider replay code.                              */
+/* ----------------------------------------------------------------------- */
+
+.history-banner {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  padding: 10px 16px;
+  background: #fff8e1;
+  border-bottom: 1px solid #f0d27a;
+  color: #5b4b00;
+  font-size: 14px;
+  z-index: 5;
+}
+.history-banner[hidden] { display: none; }
+.history-banner-label   { font-weight: 600; }
+.history-banner-rev,
+.history-banner-date    { opacity: 0.85; }
+.history-banner #history-banner-return { margin-left: auto; }
+
+/* The history iframe takes the place of the live ACE editor. We use the    */
+/* same positioning model (absolute, fill the editor area) so the page      */
+/* layout is identical between modes.                                       */
+.history-frame-mount {
+  display: none;
+  position: absolute;
+  inset: 0;
+  border: 0;
+  background: var(--bg-color, #f2f3f4);
+  z-index: 4;
+}
+.history-frame-mount[hidden] { display: none; }
+.history-frame-mount > iframe {
+  width: 100%;
+  height: 100%;
+  border: 0;
+  display: block;
+}
+
+/* While in history mode, hide the live ACE editor and show the history    */
+/* iframe in its place. The formatting menu on the left side of the        */
+/* toolbar (Bold/Italic/Lists/Indent/Undo/etc.) targets the hidden live    */
+/* editor, so we swap it for the history controls (slider + play/step      */
+/* buttons) that drive the iframe. The right-side menu (Settings / Share / */
+/* Users / Chat / Home) stays fully interactive across modes.              */
+body.history-mode #editorcontainer { display: none; }
+body.history-mode #editorcontainerbox { position: relative; }
+body.history-mode .history-frame-mount { display: block; }
+body.history-mode #editbar .menu_left { display: none; }
+body.history-mode #editbar .show-more-icon-btn { display: none; }
+body.history-mode #history-controls { display: flex; }
+
+/* History toolbar controls (issue #7659): a slider + play/pause/step      */
+/* buttons + Follow/Speed controls that remote-control the embedded        */
+/* timeslider iframe. Take the place of the formatting menu while          */
+/* scrubbing. align-items + min-height keep the toolbar the same vertical  */
+/* size as in live mode so swapping modes doesn't reflow the layout.       */
+.history-controls {
+  display: none;
+  flex: 1 1 auto;
+  align-items: center;
+  gap: 8px;
+  padding: 0 12px;
+  min-width: 0;
+  min-height: 40px;
+}
+.history-controls[hidden] { display: none; }
+.history-controls button.buttonicon {
+  flex: 0 0 auto;
+  /* Match the live-toolbar buttonicon visual weight (no <li><a> wrapper  */
+  /* gives us a smaller default; bump padding so the icon hit area lines */
+  /* up vertically with menu_right's settings/share/users/etc. icons).   */
+  padding: 6px 8px;
+  background: transparent;
+  border: 0;
+  cursor: pointer;
+  font-size: 15px;
+  color: inherit;
+}
+.history-controls button.buttonicon:hover { background: rgba(0,0,0,0.06); border-radius: 4px; }
+.history-controls button.buttonicon.buttonicon-play.pause::before {
+  content: "\e829";
+}
+.history-slider-input {
+  flex: 1 1 auto;
+  min-width: 80px;
+  margin: 0 6px;
+  cursor: pointer;
+}
+.history-timer {
+  flex: 0 0 auto;
+  font-size: 12px;
+  font-variant-numeric: tabular-nums;
+  opacity: 0.85;
+  white-space: nowrap;
+}
+.history-toggle {
+  flex: 0 0 auto;
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  font-size: 13px;
+  white-space: nowrap;
+  cursor: pointer;
+}
+.history-toggle input[type="checkbox"] { margin: 0; }
+
+/* Follow toggle — eye icon, with a diagonal slash that appears only when
+ * the underlying checkbox is unchecked (auto-follow disabled). The hidden
+ * input still drives state (so pad_mode.ts's bridge code reads .checked
+ * and the existing label-for relationship handles click). */
+.history-follow-toggle {
+  flex: 0 0 auto;
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  width: 30px;
+  height: 30px;
+  cursor: pointer;
+  border-radius: 4px;
+  color: inherit;
+}
+.history-follow-toggle:hover { background: rgba(0,0,0,0.06); }
+.history-follow-eye-slash { display: none; }
+#history-options-followContents:not(:checked) + .history-follow-toggle .history-follow-eye-slash {
+  display: inline;
+}
+#history-options-followContents:not(:checked) + .history-follow-toggle {
+  opacity: 0.55;
+}
+/* Keep the checkbox in the DOM (label-for needs a present target) but
+ * hidden visually + accessibly redundant since the label conveys state. */
+#history-options-followContents.sr-only {
+  position: absolute;
+  width: 1px; height: 1px;
+  margin: -1px; padding: 0; border: 0;
+  clip: rect(0 0 0 0); overflow: hidden;
+}
+.history-speed {
+  flex: 0 0 auto;
+  font-size: 13px;
+  padding: 2px 4px;
+  max-width: 130px;
+}
+
+/* Responsive — Follow + Speed inherit .hide-for-mobile (already collapses */
+/* at <=800px). Pack the remaining play/slider/step buttons tighter so     */
+/* they always fit. At ultra-narrow widths the step buttons compact too.   */
+@media (max-width: 800px) {
+  .history-controls { padding: 0 6px; gap: 4px; min-height: 36px; }
+  .history-controls button.buttonicon { padding: 4px 6px; min-width: 32px; }
+  .history-slider-input { min-width: 60px; margin: 0 2px; }
+}
+@media (max-width: 480px) {
+  .history-controls #history-leftstep,
+  .history-controls #history-rightstep { min-width: 28px; padding: 2px; }
+}
+
+/* Chat replay header — appears above the chat log while scrubbing so the  */
+/* user knows the message list is filtered to a historical timestamp.      */
+.history-chat-header {
+  display: none;
+  padding: 6px 10px;
+  font-size: 12px;
+  font-weight: 600;
+  background: #fff8e1;
+  color: #5b4b00;
+  border-bottom: 1px solid #f0d27a;
+}
+body.history-mode .history-chat-header { display: block; }
+body.history-mode .history-authors-row {
+  font-style: italic;
+  opacity: 0.85;
+  padding: 6px 8px;
+}

src/static/css/timeslider.css

@@ -3,6 +3,20 @@
   display: block;
 }
 
+/* When the timeslider is embedded as an iframe inside a pad page (the
+ * parent pad's history mode — issue #7659), the outer pad's toolbar,
+ * banner, slider, and Settings/Export popups own all chrome, and the
+ * iframe is purely the editor surface. The .iframe-mode class is added
+ * by timeslider.ts only when window.parent !== window, so direct visits
+ * to /p/:pad/timeslider?embed=1 (existing test/legacy entry points)
+ * keep their full chrome and stay independently usable. */
+body.embedded-history-frame.iframe-mode #editbar,
+body.embedded-history-frame.iframe-mode #import_export,
+body.embedded-history-frame.iframe-mode #connectivity,
+body.embedded-history-frame.iframe-mode #settings {
+  display: none !important;
+}
+
 .timeslider-bar {
   display: flex;
   flex-direction: row;

src/static/js/broadcast.ts

@@ -50,7 +50,10 @@ const loadBroadcastJS = (socket, sendSocketMsg, fireWhenAllScriptsAreLoaded, Bro
     }
   };
 
-  const padContents = {
+  // Exposed on `window` so the outer pad shell (issue #7659 in-place
+  // history mode) can read `currentTime` after each scrub to drive chat
+  // replay and other revision-anchored UI without postMessage round-trips.
+  const padContents: any = (window as any).padContents = {
     currentRevision: clientVars.collab_client_vars.rev,
     currentTime: clientVars.collab_client_vars.time,
     currentLines:
@@ -155,12 +158,14 @@ const loadBroadcastJS = (socket, sendSocketMsg, fireWhenAllScriptsAreLoaded, Bro
       let height;
       const nextDocLine = docLine.nextElementSibling;
       if (nextDocLine) {
-        if (lineOffsets.length === 0) {
-          height = nextDocLine.offsetTop - parseInt(
-              innerdocbodyStyles.getPropertyValue('padding-top'));
-        } else {
-          height = nextDocLine.offsetTop - docLine.offsetTop;
-        }
+        // Use the consistent (next - current) formula for every line,
+        // including the first. The previous first-line special case
+        // subtracted innerdocbody.padding-top from nextDocLine.offsetTop,
+        // which only works when innerdocbody is the offsetParent. In the
+        // in-pad history iframe (#7659) it isn't (its outerdocbody has
+        // padding-top of its own), so the first gutter row was 20px too
+        // tall and every subsequent row drifted out of alignment.
+        height = nextDocLine.offsetTop - docLine.offsetTop;
       } else {
         height = docLine.clientHeight || docLine.offsetHeight;
       }

src/static/js/chat.ts

@@ -198,6 +198,10 @@ exports.chat = (() => {
           // ctx.text was HTML-escaped before calling the hook. Hook functions are trusted to not
           // introduce an XSS vulnerability by adding unescaped user input.
           .append($('<div>').html(ctx.text).contents());
+      // The outer pad's history mode (issue #7659) filters rendered messages
+      // by this attribute when scrubbing; a missing attribute would always
+      // show the message regardless of timestamp.
+      chatMsg.attr('data-timestamp', String(msg.time));
       if (isHistoryAdd) chatMsg.insertAfter('#chatloadmessagesbutton');
       else $('#chattext').append(chatMsg);
       chatMsg.each((i, e) => html10n.translateElement(html10n.translations, e));