🎉 ヘッダーから関連チャンネルにアクセスできるように

index.html

@@ -58,6 +58,7 @@
     <div id="stamp-picker-popup"></div>
     <div id="dropdown-suggester-popup"></div>
     <div id="popup-navigator"></div>
+    <div id="popup-header-relation"></div>
     <script type="module" src="/@/main.ts"></script>
   </body>
 </html>

src/components/Main/MainView/ChannelView/ChannelHeader/ChannelHeader.vue

@@ -3,6 +3,10 @@
     <template #header>
       <div :class="$style.header">
         <channel-header-channel-name :channel-id="channelId" />
+        <channel-header-relation-button
+          :key="channelId"
+          :channel-id="channelId"
+        />
         <channel-header-topic :class="$style.topic" :channel-id="channelId" />
       </div>
     </template>
@@ -15,6 +19,7 @@
 <script lang="ts" setup>
 import PrimaryViewHeader from '/@/components/Main/MainView/PrimaryViewHeader/PrimaryViewHeader.vue'
 import ChannelHeaderChannelName from './ChannelHeaderChannelName.vue'
+import ChannelHeaderRelationButton from './ChannelHeaderRelationButton.vue'
 import ChannelHeaderTopic from './ChannelHeaderTopic.vue'
 import ChannelHeaderTools from './ChannelHeaderTools.vue'
 import type { ChannelId } from '/@/types/entity-ids'
@@ -36,7 +41,8 @@ defineProps<{
 .header {
   display: flex;
   align-items: center;
-  overflow-x: auto;
+  overflow-x: scroll;
+  margin-bottom: -6px;
 }
 .topic {
   margin-left: 16px;

src/components/Main/MainView/ChannelView/ChannelHeader/ChannelHeaderRelationButton.vue

@@ -0,0 +1,117 @@
+<template>
+  <button
+    ref="trigger"
+    type="button"
+    aria-haspopup="true"
+    :aria-expanded="isOpen"
+    :aria-controls="popupId"
+    title="関連チャンネルを表示"
+    :class="$style.trigger"
+    @click="toggle"
+  >
+    <a-icon :size="20" name="rounded-triangle" :class="$style.icon" />
+  </button>
+  <!-- NOTE: ボタンから Tab 移動した際に popup のはじめに飛べるように Focus を管理する -->
+  <div v-if="isOpen" ref="focusPopupRef" tabindex="0" @focus="focusPopup" />
+  <channel-header-relation-popup
+    v-if="isOpen"
+    ref="popup"
+    :popup-id="popupId"
+    :right-position="triggerBottomRightPosition"
+    :channel-id="props.channelId"
+    @outside-click="close"
+    @focus-return="focusTrigger"
+  />
+</template>
+
+<script setup lang="ts">
+import { onMounted, onUnmounted, ref } from 'vue'
+import AIcon from '/@/components/UI/AIcon.vue'
+import ChannelHeaderRelationPopup from './ChannelHeaderRelationPopup.vue'
+import { reactive } from 'vue'
+import type { Point } from '/@/lib/basic/point'
+import { randomString } from '/@/lib/basic/randomString'
+
+const props = defineProps<{
+  channelId: string
+}>()
+
+const trigger = ref<HTMLElement | null>(null)
+const focusPopupRef = ref<HTMLElement | null>(null)
+const popup = ref<InstanceType<typeof ChannelHeaderRelationPopup> | null>(null)
+
+const popupId = randomString()
+
+const isOpen = ref(false)
+const toggle = () => {
+  updateTriggerPosition()
+
+  isOpen.value = !isOpen.value
+}
+const close = (e: Event) => {
+  // NOTE: popup の外側かつボタンをクリックしたときに、うまく閉じないため抑制する
+  //       具体的には close -> toggle と呼ばれて閉じなくなる
+  if (trigger.value !== null && e.composedPath().includes(trigger.value)) return
+
+  isOpen.value = false
+}
+
+const triggerBottomRightPosition = reactive<Point>({
+  x: 0,
+  y: 0
+})
+const updateTriggerPosition = () => {
+  if (trigger.value === null) return
+
+  const rect = trigger.value.getBoundingClientRect()
+  triggerBottomRightPosition.x = rect.right
+  triggerBottomRightPosition.y = rect.bottom
+}
+
+onMounted(() => {
+  updateTriggerPosition()
+  window.addEventListener('resize', updateTriggerPosition)
+})
+onUnmounted(() => {
+  window.removeEventListener('resize', updateTriggerPosition)
+})
+
+const focusPopup = () => {
+  popup.value?.focus()
+}
+const focusTrigger = () => {
+  trigger.value?.focus()
+}
+</script>
+
+<style lang="scss" module>
+.trigger {
+  @include color-ui-secondary;
+  @include background-primary;
+
+  cursor: pointer;
+  overflow: hidden;
+  height: 24px;
+  width: 24px;
+  margin: 0 8px;
+  display: grid;
+  place-items: center;
+  flex-shrink: 0;
+  position: sticky;
+  right: 0;
+
+  transition: transform 0.1s;
+
+  &:hover {
+    transform: scale(1.1);
+  }
+
+  .icon {
+    transition: transform 0.5s;
+  }
+
+  &[aria-expanded='true'] .icon {
+    transform: rotate(180deg);
+  }
+}
+</style>

src/components/Main/MainView/ChannelView/ChannelHeader/ChannelHeaderRelationListItem.vue

@@ -0,0 +1,71 @@
+<template>
+  <router-link :id="linkId" :to="channelLink" :class="$style.wrap">
+    <div :class="$style.channelName"># {{ props.channel.name }}</div>
+    <div :class="[$style.topic, isTopicEmpty && $style.empty]">
+      {{ topic }}
+    </div>
+  </router-link>
+</template>
+
+<script setup lang="ts">
+import type { Channel } from '@traptitech/traq'
+import { computed } from 'vue'
+import useChannelPath from '/@/composables/useChannelPath'
+import { RouterLink } from 'vue-router'
+import { randomString } from '/@/lib/basic/randomString'
+
+const props = defineProps<{
+  channel: Channel
+}>()
+
+const linkId = randomString()
+const focus = () => {
+  // HACK: RouterLink が focus できないので、id から HTMLElement を取得して focus する
+  const link = document.getElementById(linkId) as HTMLElement | null
+  link?.focus()
+}
+
+const { channelIdToLink } = useChannelPath()
+const channelLink = computed(() => channelIdToLink(props.channel.id))
+
+const isTopicEmpty = computed(() => props.channel.topic.length === 0)
+const topic = computed(() =>
+  isTopicEmpty.value ? '[トピック未設定]' : props.channel.topic
+)
+
+defineExpose({ focus })
+</script>
+
+<style lang="scss" module>
+.wrap {
+  overflow: hidden;
+  width: 100%;
+  display: grid;
+}
+
+.channelName,
+.topic {
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+
+  contain: strict;
+  height: 1.5rem;
+  line-height: 1.5rem;
+}
+
+.channelName {
+  @include color-ui-primary;
+
+  font-weight: bold;
+}
+.topic {
+  @include color-ui-secondary;
+
+  font-size: 0.75rem;
+
+  &.empty {
+    opacity: 0.5;
+  }
+}
+</style>

src/components/Main/MainView/ChannelView/ChannelHeader/ChannelHeaderRelationPanel.vue

@@ -0,0 +1,108 @@
+<template>
+  <div :class="$style.wrap" :data-show-expand-button="showExpandButton">
+    <div v-if="isEmpty" :class="$style.empty">
+      {{ props.emptyMessage }}
+    </div>
+
+    <template v-else>
+      <ul :class="$style.list">
+        <li v-for="channel in displayedChannels" :key="channel.id">
+          <channel-header-relation-list-item
+            ref="listItemsRef"
+            :channel="channel"
+          />
+        </li>
+      </ul>
+      <form-button
+        v-if="showExpandButton"
+        :class="$style.expandButton"
+        color="secondary"
+        label="全て表示"
+        @click="expand"
+      />
+    </template>
+  </div>
+</template>
+
+<script lang="ts" setup>
+import type { Channel } from '@traptitech/traq'
+import { computed, ref, type HTMLAttributes, nextTick } from 'vue'
+import ChannelHeaderRelationListItem from './ChannelHeaderRelationListItem.vue'
+import FormButton from '/@/components/UI/FormButton.vue'
+
+interface Props extends /* @vue-ignore */ HTMLAttributes {
+  channels: Channel[]
+  emptyMessage: string
+}
+const props = defineProps<Props>()
+
+const listItemsRef = ref<InstanceType<typeof ChannelHeaderRelationListItem>[]>(
+  []
+)
+
+const isExpanded = ref(false)
+const expand = () => {
+  isExpanded.value = true
+  nextTick(() => {
+    // NOTE: すべて表示で新たに表示されるチャンネルにフォーカスする
+    //       ただし、listItemsRef の中身は表示順であることが保証されないため、find で探す
+    listItemsRef.value
+      .find(item => item.$props.channel.id === props.channels[3]?.id)
+      ?.focus()
+  })
+}
+
+const isEmpty = computed(() => props.channels.length === 0)
+const displayedChannels = computed(() => {
+  if (isExpanded.value) {
+    return props.channels
+  } else {
+    return props.channels.slice(0, 3)
+  }
+})
+const showExpandButton = computed(
+  () => props.channels.length > 3 && !isExpanded.value
+)
+</script>
+
+<style lang="scss" module>
+.wrap {
+  overflow: auto;
+  // NOTE: スクロール可能な際に、一番下がちょっと見えるような高さに設定
+  max-height: 21.75rem;
+  margin-bottom: -16px;
+  padding-bottom: 16px;
+
+  &[data-show-expand-button='false'] {
+    overflow: scroll;
+    margin-right: -4px;
+  }
+
+  &::-webkit-scrollbar-track {
+    margin-bottom: 16px;
+  }
+  &::-webkit-scrollbar {
+    width: 4px;
+  }
+}
+
+.empty {
+  @include color-ui-secondary;
+
+  padding: 16px;
+  place-items: center;
+  text-align: center;
+  font-size: 0.75rem;
+}
+
+.list {
+  display: grid;
+  grid-template-columns: 1fr;
+  gap: 0.5rem;
+}
+
+.expandButton {
+  margin-top: 0.5rem;
+  width: 100%;
+}
+</style>