rss-reader/vue/src/components/AppNav.vue

<script setup>
import { ref, computed, onMounted, onUnmounted } from 'vue'
import { RouterLink, useRouter, useRoute } from 'vue-router'
import { useFeeds, logout as logoutSession } from '@/composables/useFeeds'

const router = useRouter()
const route = useRoute()
const { sync, viewMode, toggleViewMode, layout, toggleLayout, markAllRead, feedFilter, feedTitles, setFeedFilter, unreadCount, displayedFeedUnreadCounts, refreshUnreadDisplay, lastProgrammaticScroll } = useFeeds()

const headerRef = ref(null)

// Native <select>/<option> has no "is open" state — the closed box just shows
// the selected option's text verbatim, so per-option unread counts can only be
// toggled based on focus, since the popup is only ever shown while focused.
// @focus ~ opening (shows counts); @change (picking an option closes the
// popup but keeps focus, so no blur fires) and @blur (focus left without
// picking) ~ closed (counts hidden, so the closed box just shows the name).
const filterOpen = ref(false)

function onFilterFocus() {
  filterOpen.value = true
  refreshUnreadDisplay()
}

function onFilterChange(event) {
  setFeedFilter(event.target.value || null)
  filterOpen.value = false
}

// Scroll-driven show/hide: the header slides out of view on scroll-down and
// back in only on scroll-up — never merely by proximity to the top. This is
// show/hide via `transform` (not the old resize behaviour) — the header is
// position:fixed, so translating it never reflows content. The app's
// programmatic scrolls resolve to sensible states without any top-of-page
// special case: scrollTo(0, 0) (article paging, layout toggle) is itself a
// large upward jump, so it crosses REVEAL_THRESHOLD like a real scroll-up and
// reveals the header that way; the list-view read-correction scrollBy moves
// only a few px → stays under the threshold and leaves a hidden header hidden.
const hidden = ref(false)
const REVEAL_THRESHOLD = 12 // px of accumulated travel before toggling
// When the feed list mutates itself (read-correction scrollBy + array-splice
// scroll anchoring) the page jumps *upward* without user intent. For this long
// after such a jump we gate only the reveal direction, so the jump can't pop
// the header back into view mid-read. Hiding stays allowed the whole time
// (the jump never scrolls down), so scrolling down still hides normally even
// while articles are being marked read. See lastProgrammaticScroll in useFeeds.
const PROGRAMMATIC_SUPPRESS_MS = 300
let lastY = 0
let accumulated = 0

function onScroll() {
  const y = Math.max(0, window.scrollY)

  // Keep the header visible while the menu is open (the dropdown is anchored
  // to the header, so hiding it would slide the open menu off-screen).
  if (menuOpen.value) {
    hidden.value = false
    accumulated = 0
    lastY = y
    return
  }

  const delta = y - lastY
  lastY = y
  // Reset the accumulator whenever direction flips, so the threshold is
  // measured from the last turning point (not from page load).
  if ((delta > 0) !== (accumulated > 0)) accumulated = 0
  accumulated += delta

  // Hiding (scroll-down) is always allowed. Revealing (scroll-up) is gated for
  // a short window after a programmatic list update, whose induced jump is
  // upward and would otherwise pop the header back into view mid-read. A
  // genuine scroll-up reveals once the window has elapsed.
  const afterProgrammatic = performance.now() - lastProgrammaticScroll.value < PROGRAMMATIC_SUPPRESS_MS
  if (accumulated > REVEAL_THRESHOLD) hidden.value = true // scrolling down
  else if (accumulated < -REVEAL_THRESHOLD && !afterProgrammatic) hidden.value = false // scrolling up
}

let ticking = false
function onScrollRaf() {
  if (ticking) return
  ticking = true
  requestAnimationFrame(() => {
    onScroll()
    ticking = false
  })
}

onMounted(() => {
  // Drives #app's padding-top / RssFeeds' scroll-margin-top so content below
  // the fixed header isn't hidden behind it at scroll position 0. The header is
  // a fixed size, so this is measured once on mount and never changes.
  const h = headerRef.value?.getBoundingClientRect().height ?? 0
  document.documentElement.style.setProperty('--app-nav-height', `${h}px`)

  lastY = Math.max(0, window.scrollY)
  window.addEventListener('scroll', onScrollRaf, { passive: true })
  document.addEventListener('click', onDocumentClick)
  refreshUnreadDisplay()
})

onUnmounted(() => {
  window.removeEventListener('scroll', onScrollRaf)
  document.removeEventListener('click', onDocumentClick)
})

const onFeedsPage = computed(() => route.path === '/feeds')


const menuOpen = ref(false)

function toggleMenu() {
  menuOpen.value = !menuOpen.value
}

function closeMenu() {
  menuOpen.value = false
}

// The open menu is a thin absolutely-positioned strip under the header, so its
// `@click.self` only catches clicks on that strip — a click anywhere else on
// the page never reaches it. This document-level listener closes the menu on
// any outside click. The hamburger is excluded (it has its own toggle, so an
// opening click mustn't immediately re-close), and clicks inside the menu are
// left to the menu items' own handlers.
function onDocumentClick(event) {
  if (!menuOpen.value) return
  const target = event.target
  if (target.closest?.('.app-nav__hamburger') || target.closest?.('.app-nav__menu')) return
  closeMenu()
}

async function logout() {
  await logoutSession()
  closeMenu()
  router.push({ name: 'login' })
}

function handleSync() {
  sync()
  closeMenu()
}

function handleMarkAllRead() {
  markAllRead()
  closeMenu()
}

function handleToggleViewMode() {
  toggleViewMode()
  closeMenu()
}

function handleToggleLayout() {
  toggleLayout()
  closeMenu()
}
</script>

<template>
  <header ref="headerRef" class="app-nav" :class="{ 'app-nav--hidden': hidden }">
    <div class="app-nav__wrapper">
      <span class="app-nav__title">RSS Reader<span v-if="unreadCount" class="app-nav__unread"> ({{ unreadCount }})</span></span>
      <select
        v-if="onFeedsPage && feedTitles.length"
        class="app-nav__filter"
        :value="feedFilter ?? ''"
        aria-label="Filter by feed"
        @focus="onFilterFocus"
        @change="onFilterChange"
        @blur="filterOpen = false"
      >
        <option value="">All feeds</option>
        <option v-for="title in feedTitles" :key="title" :value="title">{{ title }}<template v-if="filterOpen"> ({{ displayedFeedUnreadCounts[title] ?? 0 }})</template></option>
      </select>
      <button
        class="app-nav__hamburger"
        type="button"
        :aria-expanded="menuOpen"
        aria-controls="app-nav-menu"
        :aria-label="menuOpen ? 'Close menu' : 'Open menu'"
        @click="toggleMenu"
      >
        <span class="app-nav__hamburger-icon" aria-hidden="true">
          <span></span><span></span><span></span>
        </span>
      </button>
    </div>

    <Transition name="app-nav-menu">
      <nav
        v-if="menuOpen"
        id="app-nav-menu"
        class="app-nav__menu"
        @click.self="closeMenu"
      >
        <div class="app-nav__menu-panel">
          <RouterLink to="/feeds" class="app-nav__menu-item" @click="closeMenu">Feeds</RouterLink>
          <template v-if="onFeedsPage">
            <button class="app-nav__menu-item" type="button" @click="handleToggleViewMode">
              {{ viewMode === 'list' ? 'Article view' : 'List view' }}
            </button>
            <button v-if="viewMode === 'list'" class="app-nav__menu-item" type="button" @click="handleToggleLayout">
              {{ layout === 'list' ? 'Card layout' : 'List layout' }}
            </button>
            <button class="app-nav__menu-item" type="button" @click="handleMarkAllRead">Mark all as read</button>
          </template>
          <button class="app-nav__menu-item" type="button" @click="handleSync">Sync</button>
          <RouterLink to="/admin" class="app-nav__menu-item" @click="closeMenu">Admin</RouterLink>
          <button class="app-nav__menu-item app-nav__logout" type="button" @click="logout">Logout</button>
        </div>
      </nav>
    </Transition>
  </header>
</template>

<style scoped>
.app-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  background: var(--color-background);
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
  transition: transform 0.25s ease;
  will-change: transform;
}

.app-nav--hidden {
  transform: translateY(-100%);
}

.app-nav__wrapper {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  padding: 0.375rem 1rem;
}

.app-nav__title {
  margin-right: auto;
  font-weight: bold;
  font-size: clamp(0.95rem, 3.5vw, 1.1rem);
}

.app-nav__unread {
  font-weight: normal;
  opacity: 0.6;
}

.app-nav__filter {
  min-height: 44px;
  max-width: clamp(120px, 40vw, 220px);
  padding: 0.25rem 0.5rem;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  background: transparent;
  color: var(--color-text);
  font: inherit;
  cursor: pointer;
  text-overflow: ellipsis;
}

.app-nav__filter:hover {
  border-color: var(--color-border-hover);
}

.app-nav__hamburger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  min-width: 44px;
  padding: 0.5rem;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  background: transparent;
  cursor: pointer;
}

.app-nav__hamburger-icon {
  display: inline-flex;
  flex-direction: column;
  justify-content: space-between;
  width: 22px;
  height: 16px;
}

.app-nav__hamburger-icon span {
  display: block;
  height: 2px;
  border-radius: 1px;
  background: var(--color-text);
}

.app-nav__menu {
  position: absolute;
  inset: 100% 0 auto 0;
  z-index: 30;
  display: flex;
  justify-content: flex-end;
  padding: 0 1rem 1rem;
}

.app-nav__menu-panel {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  width: clamp(220px, 60vw, 280px);
  padding: 0.75rem;
  background: var(--color-background-soft);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.app-nav__menu-item {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0.5rem 0.9rem;
  border: 1px solid var(--color-border);
  border-radius: 4px;
  background: transparent;
  color: var(--color-text);
  text-decoration: none;
  font: inherit;
  text-align: left;
  cursor: pointer;
}

.app-nav__menu-item:hover {
  border-color: var(--color-border-hover);
}

.app-nav__menu-item.router-link-exact-active {
  font-weight: bold;
}

.app-nav-menu-enter-active,
.app-nav-menu-leave-active {
  transition: opacity 0.2s ease;
}

.app-nav-menu-enter-from,
.app-nav-menu-leave-to {
  opacity: 0;
}

@media (min-width: 768px) {
  .app-nav__wrapper {
    padding: 0.5rem 2rem;
  }
}
</style>