From 8d0db2c97c18c71bf3a6d8b08f7f3e85212e0cdb Mon Sep 17 00:00:00 2001
From: Nolan Lawson <nolan@nolanlawson.com>
Date: Sun, 5 May 2019 22:08:54 -0700
Subject: [PATCH] fix: make autosuggestion accessible (#1183)

* fix: make autosuggestion accessible

fixes #129

* remove tabindexes, fix aria-hidden
---
 .../compose/ComposeAutosuggest.html           | 22 +++++++++-
 .../compose/ComposeAutosuggestionList.html    | 44 ++++++++++++-------
 .../_components/compose/ComposeInput.html     | 19 ++++++++
 .../computations/autosuggestComputations.js   |  2 +-
 .../createAutosuggestAccessibleLabel.js       | 20 +++++++++
 tests/utils.js                                |  2 +-
 6 files changed, 89 insertions(+), 20 deletions(-)
 create mode 100644 src/routes/_utils/createAutosuggestAccessibleLabel.js

diff --git a/src/routes/_components/compose/ComposeAutosuggest.html b/src/routes/_components/compose/ComposeAutosuggest.html
index f2a04e3..5885fcf 100644
--- a/src/routes/_components/compose/ComposeAutosuggest.html
+++ b/src/routes/_components/compose/ComposeAutosuggest.html
@@ -1,11 +1,16 @@
 <div class="compose-autosuggest {shown ? 'shown' : ''} {realm === 'dialog' ? 'is-dialog' : ''}"
-       aria-hidden="true" >
+     aria-hidden={!shown}
+>
   <ComposeAutosuggestionList
     items={autosuggestSearchResults}
     on:click="onClick(event)"
     type={autosuggestType}
     selected={autosuggestSelected}
+    {realm}
   />
+  <div class="sr-only" aria-live="assertive">
+    {assertiveAriaText}
+  </div>
 </div>
 <style>
   .compose-autosuggest {
@@ -44,6 +49,7 @@
   import { selectAutosuggestItem } from '../../_actions/autosuggest'
   import { observe } from 'svelte-extras'
   import { once } from '../../_utils/once'
+  import { createAutosuggestAccessibleLabel } from '../../_utils/createAutosuggestAccessibleLabel'
 
   export default {
     oncreate () {
@@ -94,7 +100,19 @@
       /* eslint-enable camelcase */
       shouldBeShown: ({ realm, $autosuggestShown, composeFocused }) => (
         !!($autosuggestShown && composeFocused)
-      )
+      ),
+      // text that is read to screen readers. based on https://haltersweb.github.io/Accessibility/autocomplete.html
+      assertiveAriaText: ({ shouldBeShown,
+        autosuggestSearchResults,
+        autosuggestSelected,
+        autosuggestType,
+        $omitEmojiInDisplayNames }) => {
+        if (!shouldBeShown || !autosuggestSearchResults || !autosuggestSearchResults.length) {
+          return ''
+        }
+        return createAutosuggestAccessibleLabel(autosuggestType, $omitEmojiInDisplayNames,
+          autosuggestSelected, autosuggestSearchResults)
+      }
     },
     data: () => ({
       shown: false
diff --git a/src/routes/_components/compose/ComposeAutosuggestionList.html b/src/routes/_components/compose/ComposeAutosuggestionList.html
index 23cd7e8..ff42a51 100644
--- a/src/routes/_components/compose/ComposeAutosuggestionList.html
+++ b/src/routes/_components/compose/ComposeAutosuggestionList.html
@@ -1,10 +1,17 @@
-<ul class="compose-autosuggest-list">
+<!-- accessible autocomplete, based on https://haltersweb.github.io/Accessibility/autocomplete.html -->
+<ul id="compose-autosuggest-list-{realm}"
+    class="compose-autosuggest-list"
+    role="listbox"
+>
   {#each items as item, i (item.shortcode ? `emoji-${item.shortcode}` : `account-${item.id}`)}
-  <li class="compose-autosuggest-list-item">
-    <button class="compose-autosuggest-list-button {i === selected ? 'selected' : ''}"
-            tabindex="0"
-            on:click="onClick(event, item)">
-      <div class="compose-autosuggest-list-grid">
+  <li id="{i === selected ? `compose-autosuggest-active-item-${realm}` : ''}"
+      class="compose-autosuggest-list-item {i === selected ? 'selected' : ''}"
+      role="option"
+      aria-selected="{i === selected}"
+      aria-label="{ariaLabels[i]}"
+      on:click="onClick(event, item)"
+  >
+      <div class="compose-autosuggest-list-grid" aria-hidden="true">
         {#if type === 'account'}
         <div class="compose-autosuggest-list-item-avatar">
           <Avatar
@@ -28,7 +35,6 @@
           </span>
         {/if}
       </div>
-    </button>
   </li>
   {/each}
 </ul>
@@ -43,17 +49,15 @@
   .compose-autosuggest-list-item {
     border-bottom: 1px solid var(--compose-autosuggest-outline);
     display: flex;
+    padding: 10px;
+    background: var(--settings-list-item-bg);
+    margin: 0;
+    flex: 1;
+    cursor: pointer;
   }
   .compose-autosuggest-list-item:last-child {
     border-bottom: none;
   }
-  .compose-autosuggest-list-button {
-    padding: 10px;
-    background: var(--settings-list-item-bg);
-    border: none;
-    margin: 0;
-    flex: 1;
-  }
   .compose-autosuggest-list-grid {
     display: grid;
     width: 100%;
@@ -90,10 +94,10 @@
     text-overflow: ellipsis;
     text-align: left;
   }
-  .compose-autosuggest-list-button:hover, .compose-autosuggest-list-button.selected {
+  .compose-autosuggest-list-item:hover, .compose-autosuggest-list-item.selected {
     background: var(--compose-autosuggest-item-hover);
   }
-  .compose-autosuggest-list-button:active {
+  .compose-autosuggest-list-item:active {
     background: var(--compose-autosuggest-item-active);
   }
 </style>
@@ -101,9 +105,17 @@
   import Avatar from '../Avatar.html'
   import { store } from '../../_store/store'
   import AccountDisplayName from '../profile/AccountDisplayName.html'
+  import { createAutosuggestAccessibleLabel } from '../../_utils/createAutosuggestAccessibleLabel'
 
   export default {
     store: () => store,
+    computed: {
+      ariaLabels: ({ items, type, $omitEmojiInDisplayNames }) => {
+        return items.map((item, i) => {
+          return createAutosuggestAccessibleLabel(type, $omitEmojiInDisplayNames, i, items)
+        })
+      }
+    },
     methods: {
       onClick (event, item) {
         event.preventDefault()
diff --git a/src/routes/_components/compose/ComposeInput.html b/src/routes/_components/compose/ComposeInput.html
index ff93779..ac2ae17 100644
--- a/src/routes/_components/compose/ComposeInput.html
+++ b/src/routes/_components/compose/ComposeInput.html
@@ -2,6 +2,11 @@
   id="the-compose-box-input-{realm}"
   class="compose-box-input compose-box-input-realm-{realm}"
   placeholder="What's on your mind?"
+  aria-describedby="compose-box-input-description-{realm}"
+  aria-owns="compose-autosuggest-list-{realm}"
+  aria-expanded={autosuggestShownForThisInput}
+  aria-autocomplete="both"
+  aria-activedescendant="{autosuggestShownForThisInput ? `compose-autosuggest-active-item-${realm}` : ''}"
   ref:textarea
   bind:value=rawText
   on:blur="onBlur()"
@@ -12,6 +17,9 @@
 <label for="the-compose-box-input-{realm}" class="sr-only">
   What's on your mind?
 </label>
+<span id="compose-box-input-description-{realm}" class="sr-only">
+  When autocomplete results are available, press up or down arrows and enter to select.
+</span>
 <style>
   .compose-box-input {
     grid-area: input;
@@ -59,6 +67,7 @@
     clickSelectedAutosuggestionEmoji
   } from '../../_actions/autosuggest'
   import { observe } from 'svelte-extras'
+  import { get } from '../../_utils/lodash-lite'
 
   export default {
     oncreate () {
@@ -214,6 +223,16 @@
     data: () => ({
       rawText: ''
     }),
+    computed: {
+      /* eslint-disable camelcase */
+      composeFocused: ({ $autosuggestData_composeFocused, $currentInstance, realm }) => (
+        get($autosuggestData_composeFocused, [$currentInstance, realm], false)
+      ),
+      /* eslint-enable camelcase */
+      autosuggestShownForThisInput: ({ realm, $autosuggestShown, composeFocused }) => (
+        !!($autosuggestShown && composeFocused)
+      )
+    },
     events: {
       selectionChange
     }
diff --git a/src/routes/_store/computations/autosuggestComputations.js b/src/routes/_store/computations/autosuggestComputations.js
index 7384b16..bbe4ff2 100644
--- a/src/routes/_store/computations/autosuggestComputations.js
+++ b/src/routes/_store/computations/autosuggestComputations.js
@@ -1,6 +1,6 @@
 import { get } from '../../_utils/lodash-lite'
 
-const MIN_PREFIX_LENGTH = 1
+const MIN_PREFIX_LENGTH = 2
 const ACCOUNT_SEARCH_REGEX = new RegExp(`(?:\\s|^)(@\\S{${MIN_PREFIX_LENGTH},})$`)
 const EMOJI_SEARCH_REGEX = new RegExp(`(?:\\s|^)(:[^:]{${MIN_PREFIX_LENGTH},})$`)
 
diff --git a/src/routes/_utils/createAutosuggestAccessibleLabel.js b/src/routes/_utils/createAutosuggestAccessibleLabel.js
new file mode 100644
index 0000000..8e072cd
--- /dev/null
+++ b/src/routes/_utils/createAutosuggestAccessibleLabel.js
@@ -0,0 +1,20 @@
+import { removeEmoji } from './removeEmoji'
+
+export function createAutosuggestAccessibleLabel (
+  autosuggestType, $omitEmojiInDisplayNames,
+  selectedIndex, searchResults) {
+  let selected = searchResults[selectedIndex]
+  let label
+  if (autosuggestType === 'emoji') {
+    label = `${selected.shortcode}`
+  } else { // account
+    let displayName = selected.display_name || selected.username
+    let emojis = selected.emojis || []
+    displayName = $omitEmojiInDisplayNames
+      ? removeEmoji(displayName, emojis) || displayName
+      : displayName
+    label = `${displayName} @${selected.acct}`
+  }
+  return `${label} (${selectedIndex + 1} of ${searchResults.length}). ` +
+    `Press up and down arrows to review and enter to select.`
+}
diff --git a/tests/utils.js b/tests/utils.js
index bb683ef..d596211 100644
--- a/tests/utils.js
+++ b/tests/utils.js
@@ -213,7 +213,7 @@ export function getNthPostPrivacyButton (n) {
 }
 
 export function getNthAutosuggestionResult (n) {
-  return $(`.compose-autosuggest-list-item:nth-child(${n}) button`)
+  return $(`.compose-autosuggest-list-item:nth-child(${n})`)
 }
 
 export function getSearchResultByHref (href) {