save focus when using keyboard navigation

routes/_components/status/Status.html

@@ -1,7 +1,8 @@
 <article class="status-article {{getClasses(originalStatus, timelineType, isStatusInOwnThread)}}"
          tabindex="0"
-         delegate-click-key="{{delegateKey}}"
-         delegate-keydown-key="{{delegateKey}}"
+         delegate-click-key="{{elementKey}}"
+         delegate-keydown-key="{{elementKey}}"
+         focus-key="{{elementKey}}"
          aria-posinset="{{index}}"
          aria-setsize="{{length}}"
          aria-label="Status by {{originalStatus.account.display_name || originalStatus.account.username}}"
@@ -94,15 +95,15 @@
 
   export default {
     oncreate() {
-      let delegateKey = this.get('delegateKey')
+      let elementKey = this.get('elementKey')
       let onClickOrKeydown = this.onClickOrKeydown.bind(this)
-      registerDelegate('click', delegateKey, onClickOrKeydown)
-      registerDelegate('keydown', delegateKey, onClickOrKeydown)
+      registerDelegate('click', elementKey, onClickOrKeydown)
+      registerDelegate('keydown', elementKey, onClickOrKeydown)
     },
     ondestroy() {
-      let delegateKey = this.get('delegateKey')
-      unregisterDelegate('click', delegateKey)
-      unregisterDelegate('keydown', delegateKey)
+      let elementKey = this.get('elementKey')
+      unregisterDelegate('click', elementKey)
+      unregisterDelegate('keydown', elementKey)
     },
     components: {
       StatusSidebar,
@@ -147,7 +148,7 @@
     computed: {
       originalStatus: (status) => status.reblog ? status.reblog : status,
       statusId: (originalStatus) => originalStatus.id,
-      delegateKey: (statusId, timelineType, timelineValue) => `status-${timelineType}-${timelineValue}-${statusId}`,
+      elementKey: (statusId, timelineType, timelineValue) => `status-${timelineType}-${timelineValue}-${statusId}`,
       contextualStatusId: ($currentInstance, timelineType, timelineValue, status, notification) => {
         return `${$currentInstance}/${timelineType}/${timelineValue}/${notification ? notification.id : ''}/${status.id}`
       },

routes/_components/status/StatusAuthorName.html

@@ -1,5 +1,7 @@
 <a class="status-author-name {{isStatusInNotification ? 'status-in-notification' : '' }} {{isStatusInOwnThread ? 'status-in-own-thread' : ''}}"
-   href="/accounts/{{status.account.id}}">
+   href="/accounts/{{status.account.id}}"
+   focus-key="{{focusKey}}"
+>
   {{status.account.display_name || status.account.username}}
 </a>
 <style>
@@ -31,27 +33,10 @@
 
 </style>
 <script>
-  import IntlRelativeFormat from 'intl-relativeformat'
-  import ExternalLink from '../ExternalLink.html'
-  import { mark, stop } from '../../_utils/marks'
-
-  const relativeFormat = new IntlRelativeFormat('en-US');
-
   export default {
-    helpers: {
-      getClass: isStatusInNotification => isStatusInNotification ? 'status-author-in-notification' : ''
-    },
     computed: {
-      createdAtDate: (status) => status.created_at,
-      relativeDate: (createdAtDate) => {
-        mark('compute relativeDate')
-        let res = relativeFormat.format(new Date(createdAtDate))
-        stop('compute relativeDate')
-        return res
-      }
-    },
-    components: {
-      ExternalLink
+      statusId: (status) => status.id,
+      focusKey: (statusId) => `status-author-name-${statusId}`
     }
   }
 </script>

routes/_components/status/StatusContent.html

@@ -72,7 +72,8 @@
           }
         }
         return content
-      }
+      },
+      statusId: (status) => status.id
     },
     methods: {
       hydrateContent() {
@@ -80,6 +81,8 @@
           return
         }
         let status = this.get('status')
+        let statusId = this.get('statusId')
+        let count = 0
         mark('hydrateContent')
         if (status.tags && status.tags.length) {
           let anchorTags = Array.from(this.refs.node.querySelectorAll(
@@ -88,6 +91,7 @@
             for (let anchorTag of anchorTags) {
               if (anchorTag.getAttribute('href').endsWith(`/tags/${tag.name}`)) {
                 anchorTag.setAttribute('href', `/tags/${tag.name}`)
+                anchorTag.setAttribute('focus-key', `status-content-link-${statusId}-${++count}`)
                 anchorTag.removeAttribute('target')
                 anchorTag.removeAttribute('rel')
               }
@@ -101,6 +105,7 @@
             for (let anchorTag of anchorTags) {
               if (anchorTag.getAttribute('href') === mention.url) {
                 anchorTag.setAttribute('href', `/accounts/${mention.id}`)
+                anchorTag.setAttribute('focus-key', `status-content-link-${statusId}-${++count}`)
                 anchorTag.removeAttribute('target')
                 anchorTag.removeAttribute('rel')
               }

routes/_components/status/StatusHeader.html

@@ -3,7 +3,9 @@
     <use xlink:href="{{getIcon(notification, status)}}"/>
   </svg>
   <span>
-    <a href="/accounts/{{getAccount(notification, status).id}}">
+    <a href="/accounts/{{getAccount(notification, status).id}}"
+       focus-key="{{focusKey}}"
+    >
       {{getAccount(notification, status).display_name || ('@' + getAccount(notification, status).username)}}
     </a>
     {{#if notification && notification.type === 'reblog'}}
@@ -62,6 +64,10 @@
 </style>
 <script>
   export default {
+    computed: {
+      statusId: (status) => status.id,
+      focusKey: (statusId) => `status-header-${statusId}`
+    },
     helpers: {
       getIcon(notification, status) {
         if ((notification && notification.type === 'reblog') || (status && status.reblog)) {

routes/_components/status/StatusRelativeDate.html

@@ -1,5 +1,7 @@
 <a class="status-relative-date {{isStatusInNotification ? 'status-in-notification' : '' }}"
-   href="/statuses/{{status.id}}">
+   href="/statuses/{{status.id}}"
+   focus-key="{{focusKey}}"
+>
   <time datetime={{createdAtDate}} title="{{relativeDate}}" aria-label="{{relativeDate}} – click to show thread">{{relativeDate}}</time>
 </a>
 <style>
@@ -32,12 +34,14 @@
   export default {
     computed: {
       createdAtDate: (status) => status.created_at,
+      statusId: (status) => status.id,
       relativeDate: (createdAtDate) => {
         mark('compute relativeDate')
         let res = relativeFormat.format(new Date(createdAtDate))
         stop('compute relativeDate')
         return res
-      }
+      },
+      focusKey: (statusId) => `status-relative-date-${statusId}`
     }
   }
 </script>

routes/_components/timeline/Timeline.html

@@ -1,4 +1,9 @@
-<div class="timeline" role="feed" aria-label="{{label}}">
+<div class="timeline"
+     role="feed"
+     aria-label="{{label}}"
+     on:focusWithCapture="saveFocus(event)"
+     on:blurWithCapture="clearFocus(event)"
+>
   {{#if !$initialized}}
     <LoadingPage />
   {{/if}}
@@ -55,11 +60,22 @@
   import { database } from '../../_database/database'
   import { initializeTimeline, fetchTimelineItemsOnScrollToBottom, setupTimeline } from '../../_actions/timeline'
   import LoadingPage from '../LoadingPage.html'
+  import { focusWithCapture, blurWithCapture } from '../../_utils/events'
 
   export default {
-    async oncreate() {
+    oncreate() {
       console.log('timeline oncreate()')
+      this.onPushState = this.onPushState.bind(this)
+      this.store.setForCurrentTimeline({ignoreBlurEvents: false})
+      window.addEventListener('pushState', this.onPushState)
       setupTimeline()
+      if (this.store.get('initialized')) {
+        this.restoreFocus()
+      }
+    },
+    ondestroy() {
+      console.log('ondestroy')
+      window.removeEventListener('pushState', this.onPushState)
     },
     data: () => ({
       StatusVirtualListItem,
@@ -109,6 +125,10 @@
       PseudoVirtualList,
       LoadingPage
     },
+    events: {
+      focusWithCapture,
+      blurWithCapture
+    },
     methods: {
       initialize() {
         if (this.store.get('initialized') || !this.store.get('timelineItemIds')) {
@@ -117,6 +137,9 @@
         console.log('timeline initialize()')
         initializeTimeline()
       },
+      onPushState() {
+        this.store.setForCurrentTimeline({ ignoreBlurEvents: true })
+      },
       onScrollToBottom() {
         if (!this.store.get('initialized') ||
             this.store.get('runningUpdate') ||
@@ -124,7 +147,49 @@
           return
         }
         fetchTimelineItemsOnScrollToBottom()
+      },
+      saveFocus(e) {
+        let instanceName = this.store.get('currentInstance')
+        let timelineName = this.get('timeline')
+        let lastFocusedElementSelector
+        let activeElement = e.target
+        if (activeElement) {
+          let focusKey = activeElement.getAttribute('focus-key')
+          if (focusKey) {
+            lastFocusedElementSelector = `[focus-key=${focusKey}]`
           }
         }
+        console.log('saving focus to ', lastFocusedElementSelector)
+        this.store.setForTimeline(instanceName, timelineName, {
+          lastFocusedElementSelector
+        })
+      },
+      clearFocus() {
+        if (this.store.get('ignoreBlurEvents')) {
+          return
+        }
+        console.log('clearing focus')
+        let instanceName = this.store.get('currentInstance')
+        let timelineName = this.get('timeline')
+        this.store.setForTimeline(instanceName, timelineName, {
+          lastFocusedElementSelector: null
+        })
+      },
+      restoreFocus() {
+        let lastFocusedElementSelector = this.store.get('lastFocusedElementSelector')
+        console.log('lastFocused', lastFocusedElementSelector)
+        if (lastFocusedElementSelector) {
+          requestAnimationFrame(() => {
+            requestAnimationFrame(() => {
+              let element = document.querySelector(lastFocusedElementSelector)
+              console.log('el', element)
+              if (element) {
+                element.focus()
+              }
+            })
+          })
+        }
+      },
+    }
   }
 </script>

routes/_store/mixins.js

@@ -12,6 +12,12 @@ function timelineMixins (Store) {
     let timelineData = timelines[instanceName] || {}
     return (timelineData[timelineName] || {})[key]
   }
+
+  Store.prototype.setForCurrentTimeline = function (obj) {
+    let instanceName = this.get('currentInstance')
+    let timelineName = this.get('currentTimeline')
+    this.setForTimeline(instanceName, timelineName, obj)
+  }
 }
 
 export function mixins (Store) {

routes/_store/timelineComputations.js

@@ -1,11 +1,20 @@
+
+function computeForTimeline(store, key) {
+  store.compute(key, ['currentTimelineData'], (currentTimelineData) => currentTimelineData[key])
+}
+
+
 export function timelineComputations (store) {
   store.compute('currentTimelineData', ['currentInstance', 'currentTimeline', 'timelines'],
     (currentInstance, currentTimeline, timelines) => {
       return ((timelines && timelines[currentInstance]) || {})[currentTimeline] || {}
     })
 
-  store.compute('timelineItemIds', ['currentTimelineData'], (currentTimelineData) => currentTimelineData.timelineItemIds)
-  store.compute('runningUpdate', ['currentTimelineData'], (currentTimelineData) => currentTimelineData.runningUpdate)
-  store.compute('initialized', ['currentTimelineData'], (currentTimelineData) => currentTimelineData.initialized)
+  computeForTimeline(store, 'timelineItemIds')
+  computeForTimeline(store, 'runningUpdate')
+  computeForTimeline(store, 'initialized')
+  computeForTimeline(store, 'lastFocusedElementSelector')
+  computeForTimeline(store, 'ignoreBlurEvents')
+
   store.compute('lastTimelineItemId', ['timelineItemIds'], (timelineItemIds) => timelineItemIds && timelineItemIds.length && timelineItemIds[timelineItemIds.length - 1])
 }

routes/_utils/events.js

@@ -34,3 +34,21 @@ export function mouseover (node, callback) {
     }
   }
 }
+
+export function focusWithCapture (node, callback) {
+  node.addEventListener('focus', callback, true)
+  return {
+    teardown () {
+      node.removeEventListener('focus', callback, true)
+    }
+  }
+}
+
+export function blurWithCapture (node, callback) {
+  node.addEventListener('blur', callback, true)
+  return {
+    teardown () {
+      node.removeEventListener('blur', callback, true)
+    }
+  }
+}

routes/_utils/historyEvents.js

@@ -0,0 +1,18 @@
+// hacky way to listen for pushState/replaceState changes
+// per https://stackoverflow.com/a/25673911/680742
+
+function wrapper (type) {
+  let orig = history[type]
+  return function () {
+    let result = orig.apply(this, arguments)
+    let e = new Event(type)
+    e.arguments = arguments
+    window.dispatchEvent(e)
+    return result
+  }
+}
+
+if (process.browser) {
+  history.pushState = wrapper('pushState')
+  history.replaceState = wrapper('replaceState')
+}

templates/main.js

@@ -2,6 +2,7 @@ import { init } from 'sapper/runtime.js'
 import { loadPolyfills } from '../routes/_utils/loadPolyfills'
 import '../routes/_utils/offlineNotification'
 import '../routes/_utils/serviceWorkerClient'
+import '../routes/_utils/historyEvents'
 
 loadPolyfills().then(() => {
   // `routes` is an array of route objects injected by Sapper