Loop media pager through loaded posts and show position

1 files changed, 44 insertions, 56 deletions

diff --git a/src/features/messages.js b/src/features/messages.js
index 6d3aefa..ccba6ad 100644
--- a/src/features/messages.js
+++ b/src/features/messages.js
@@ -12142,7 +12142,7 @@ export function messagesFeature(ctx) {
   function dropPager() {
     const p = pager;
     pager = null;
-    try { p.io.disconnect(); p.near.disconnect(); p.tailIo.disconnect(); } catch {}
+    try { p.io.disconnect(); p.near.disconnect(); } catch {}
     clearInterval(p.tick);
     cancelAnimationFrame(p.raf);
     window.removeEventListener('resize', p.onResize);
@@ -12513,13 +12513,18 @@ export function messagesFeature(ctx) {
     if (!pager) return false;
     const here = pagerHere();
     if (v) {
-      const from = pager.onTail || !here ? pager.tail : here.closest('.mp-group');
-      const to = from && (v > 0 ? from.nextElementSibling : from.previousElementSibling);
-      if (to) pagerGlide(pager.scroller, 'y', pagerAt(pager.scroller, to, true));
+      const groups = pagerGroups();
+      const from = here && here.closest('.mp-group');
+      const index = groups.indexOf(from) + v;
+      const to = groups[(index + groups.length) % groups.length];
+      if (to) {
+        if (index < 0 || index >= groups.length) pagerWrap(to);
+        else pagerGlide(pager.scroller, 'y', pagerAt(pager.scroller, to, true));
+      }
       return !!to;
     }
     if (hz) {
-      const to = !pager.onTail && here && (hz > 0 ? here.nextElementSibling : here.previousElementSibling);
+      const to = here && (hz > 0 ? here.nextElementSibling : here.previousElementSibling);
       if (to) pagerGlide(here.parentElement, 'x', pagerAt(here.parentElement, to, false));
       return !!to;
     }
@@ -12536,7 +12541,8 @@ export function messagesFeature(ctx) {
   let fly = null; // { to: the post flown to, n: notches in this run, at, dir }
   function pagerFly(dir, now) {
     if (!pager) return;
-    const stops = [...pager.scroller.children]; // the posts, then the tail
+    const stops = pagerGroups();
+    if (!stops.length) return;
     const live = fly && now - fly.at < 400 && pager.scroller._glide;
     let from, n = 1;
     if (live && fly.dir === dir) { from = fly.to; n = fly.n + 1; }
@@ -12545,9 +12551,11 @@ export function messagesFeature(ctx) {
       from = stops.reduce((b, g) => (Math.abs(g.offsetTop - y) < Math.abs(b.offsetTop - y) ? g : b));
     } else {
       const here = pagerHere();
-      from = pager.onTail || !here ? pager.tail : here.closest('.mp-group');
+      from = here && here.closest('.mp-group');
     }
-    const i = Math.max(0, Math.min(stops.length - 1, stops.indexOf(from) + dir * (n <= 2 ? 1 : 2)));
+    const next = stops.indexOf(from) + dir * (n <= 2 ? 1 : 2);
+    const i = (next % stops.length + stops.length) % stops.length;
+    if (next < 0 || next >= stops.length) { fly = null; pagerWrap(stops[i]); return; }
     const to = stops[i];
     fly = { to, n, at: now, dir };
     if (live) pager.scroller._onDone = null; // the flight goes on: not a landing
@@ -12567,11 +12575,30 @@ export function messagesFeature(ctx) {
     pager.el.classList.toggle('has-right', !!slide.nextElementSibling);
   }
 
+  // Crossing the boundary jumps directly to the other end, without flying
+  // backwards through every loaded post or waiting for a network request.
+  function pagerWrap(group) {
+    if (!pager || !group) return;
+    pager.scroller._onDone = null;
+    pagerHold(pager.scroller);
+    pager.scroller.style.scrollSnapType = '';
+    pager.flying = false;
+    const slide = rowSlide(group);
+    if (slide) { pagerShow(slide); pagerArrive(slide); }
+  }
+  function pagerPosition() {
+    if (!pager) return;
+    const slides = pagerSlides();
+    const index = slides.indexOf(pager.cur || pager.anchor);
+    pager.el.querySelector('.mp-position').textContent = (index < 0 ? 0 : index + 1) + ' / ' + slides.length;
+  }
+
   function buildPager(want) {
     const video = want.kind === 'videos';
     const scroller = h('div', { class: 'mp-scroll' });
     const el = h('div', { class: 'media-pager' + (video ? ' videos' : '') + (pagerLoud ? '' : ' quiet'), role: 'dialog', 'aria-modal': 'true' },
       scroller,
+      h('div', { class: 'mp-position', role: 'status' }, '0 / 0'),
       h('div', { class: 'mp-top' },
         h('button', { class: 'mp-x', type: 'button', 'aria-label': t('close'), onClick: (e) => { e.stopPropagation(); dismissPager(); } }, '×'),
         video ? h('button', { class: 'mp-sound', type: 'button', onClick: (e) => { e.stopPropagation(); pagerSound(!pagerLoud); } },
@@ -12662,11 +12689,13 @@ export function messagesFeature(ctx) {
     // let go of a drag: on to the next (or the one before), or back
     function settle(d, step, vel = 0) {
       const box = d.box, y = d.axis === 'y';
-      const stops = [...box.children].filter((c) => c.matches(y ? '.mp-group, .mp-tail' : '.mp-slide')).map((c) => pagerAt(box, c, y));
+      const stops = [...box.children].filter((c) => c.matches(y ? '.mp-group' : '.mp-slide')).map((c) => pagerAt(box, c, y));
       if (!stops.length) return;
       // the stop it set off from, then one along (or back)
       const from = stops.reduce((bi, p, i) => (Math.abs(p - d.start) < Math.abs(stops[bi] - d.start) ? i : bi), 0);
-      pagerGlide(box, d.axis, stops[Math.min(stops.length - 1, Math.max(0, from + step))], vel);
+      const next = from + step;
+      if (y && (next < 0 || next >= stops.length)) { pagerWrap(pagerGroups()[(next + stops.length) % stops.length]); return; }
+      pagerGlide(box, d.axis, stops[Math.min(stops.length - 1, Math.max(0, next))], vel);
     }
     el.addEventListener('touchend', (e) => {
       const d = touch;
@@ -12700,7 +12729,7 @@ export function messagesFeature(ctx) {
     });
     // a tap shows (or hides) who posted it and what they said
     function pagerTap(target) {
-      if (target.closest('button, a, .mp-caption, .mp-seek, .mp-tail')) return;
+      if (target.closest('button, a, .mp-caption, .mp-seek')) return;
       if (Date.now() - videoTapAt < 800) return; // the click of the touch that opened it
       if (pager && video) {
         // A clip (from the feed or the media grid): a tap anywhere but the
@@ -12727,32 +12756,6 @@ export function messagesFeature(ctx) {
       if (el.classList.contains('show')) pagerCounts(pager && pager.cur);
     }
     pager = { el, scroller, kind: want.kind, keys: new Set(), cur: null, feed: want.feed, fromFeed: !!want.fromFeed, profile: want.profile || null, start: want.start, at: want.at || 0 };
-    // The end of the pager: swiping past the last slide lands here, on
-    // something saying more is coming (not a nudge that goes nowhere) — and
-    // asks for it at once. Slides that arrive go in above it; one arriving
-    // while the reader waits here is moved onto, and plays. With nothing
-    // more to be had, it says so.
-    const tail = h('div', { class: 'mp-tail', 'aria-live': 'polite' },
-      h('div', { class: 'mp-loader', 'aria-hidden': 'true', html: video
-        ? '<span class="mp-orbit"><i></i><i></i><i></i></span><span class="mp-core"><svg viewBox="0 0 24 24" width="30" height="30"><path d="M8 5.5v13l10.5-6.5z" fill="currentColor"/></svg></span>'
-        : '<span class="mp-orbit"><i></i><i></i><i></i></span><span class="mp-core"><svg viewBox="0 0 24 24" width="28" height="28" fill="none" stroke="currentColor" stroke-width="2" stroke-linejoin="round"><rect x="3.5" y="4.5" width="17" height="15" rx="2.5"/><path d="M3.5 16l5-5 4 4 2.5-2.5 5 5"/><circle cx="15.5" cy="9" r="1.6" fill="currentColor" stroke="none"/></svg></span>' }),
-      h('div', { class: 'mp-tail-text' }, t(video ? 'pagerFetchingVideo' : 'pagerFetchingPictures')));
-    tail._tail = true;
-    scroller.append(tail);
-    pager.tail = tail;
-    pager.tailIo = new IntersectionObserver((entries) => {
-      for (const e of entries) {
-        if (!pager) return;
-        pager.onTail = e.isIntersecting && e.intersectionRatio >= 0.6;
-        if (!pager.onTail) continue;
-        const v = pager.cur && pager.cur.querySelector('video.mp-media');
-        if (v) v.pause();
-        el.classList.remove('show');
-        if (pagerSource()) pagerFeedAhead(); else crawlMedia().catch(() => {});
-        pagerTailState();
-      }
-    }, { root: scroller, threshold: [0, 0.6] });
-    pager.tailIo.observe(tail);
     pager.near = new IntersectionObserver((entries) => {
       for (const e of entries) {
         if (!e.isIntersecting) continue;
@@ -12776,6 +12779,7 @@ export function messagesFeature(ctx) {
       pager.anchor = slide;
       pager.curAt = Date.now();
       pagerArrows(slide);
+      pagerPosition();
       if (pager.fromFeed) { const row = feedNow().notes.find((x) => x.id === slide._rowId); markSeen(row || slide._ev); }
       else if (pager.profile) markSeen(slide._ev);
       playSlide(slide);
@@ -12818,8 +12822,7 @@ export function messagesFeature(ctx) {
     pager.onResize = () => {
       if (!pager) return;
       pager.screenH = pager.scroller.clientHeight;
-      if (pager.onTail) pager.scroller.scrollTop = pager.tail.offsetTop;
-      else if (pager.anchor) pagerShow(pager.anchor);
+      if (pager.anchor) pagerShow(pager.anchor);
     };
     window.addEventListener('resize', pager.onResize);
     // new posts land in the feed while the pager is open; counts move
@@ -12857,8 +12860,6 @@ export function messagesFeature(ctx) {
   function growPager() {
     if (!pager) return;
     const c = feedNow();
-    const waiting = pager.onTail;
-    let first = null;
     pager.groups ||= new Map();
     const src = pagerSource();
     for (const it of (src ? src.items(pager.kind) : mediaItems(c, pager.kind))) {
@@ -12871,17 +12872,14 @@ export function messagesFeature(ctx) {
       if (!g) {
         g = pagerGroup();
         pager.groups.set(gk, g);
-        pager.scroller.insertBefore(g, pager.tail || null);
-        first ||= s;
+        pager.scroller.append(g);
       }
       g._row.append(s);
       pagerDots(g);
       pager.near.observe(s);
       pager.io.observe(s);
     }
-    // the reader was waiting at the end: onto the first that came
-    if (waiting && first) { pager.onTail = false; pagerShow(first); }
-    pagerTailState();
+    pagerPosition();
   }
   // A post in the pager: its row of slides, side by side, and — with more
   // than one — dots saying how many and which.
@@ -12899,16 +12897,6 @@ export function messagesFeature(ctx) {
     const at = rowSlide(g);
     [...g._dots.children].forEach((d, i) => d.classList.toggle('on', g._row.children[i] === at));
   }
-  // the end says "more coming", or — the feed (or the media index) has no
-  // more to give — that this is everything
-  function pagerTailState() {
-    if (!pager || !pager.tail) return;
-    const src = pagerSource();
-    const done = src ? src.done() : !!mediaIndex(feedNow().id).end;
-    if (pager.tail.classList.contains('done') === done) return;
-    pager.tail.classList.toggle('done', done);
-    pager.tail.querySelector('.mp-tail-text').textContent = done ? t('pagerCaughtUp') : t(pager.kind === 'videos' ? 'pagerFetchingVideo' : 'pagerFetchingPictures');
-  }
   if (typeof window !== 'undefined') {
     window.addEventListener('keydown', (e) => {
       if (!pager || e.defaultPrevented) return;