feat: add length gauge for media alt text editor (#1431)

* feat: add length gauge for media alt text editor

* fix test

src/routes/_components/LengthGauge.html

@@ -0,0 +1,59 @@
+<div class="length-gauge {shouldAnimate ? 'should-animate' : ''}  {overLimit ? 'over-char-limit' : ''}"
+     style={computedStyle}
+     aria-hidden="true"
+></div>
+<style>
+  .length-gauge {
+    height: 2px;
+    background: var(--main-theme-color);
+    transform-origin: left;
+  }
+  .length-gauge.should-animate {
+    transition: transform 0.2s linear;
+  }
+  .length-gauge.over-char-limit {
+    background: var(--warning-color);
+  }
+</style>
+<script>
+  import { mark, stop } from '../_utils/marks'
+  import { store } from '../_store/store'
+  import { observe } from 'svelte-extras'
+  import { throttleTimer } from '../_utils/throttleTimer'
+
+  const updateDisplayedLength = process.browser && throttleTimer(requestAnimationFrame)
+
+  export default {
+    oncreate () {
+      const { lengthAsFraction } = this.get()
+      this.set({ lengthAsFractionDeferred: lengthAsFraction })
+      // perf improvement for keyboard input latency
+      this.observe('lengthAsFraction', () => {
+        updateDisplayedLength(() => {
+          mark('set lengthAsFractionDeferred')
+          const { lengthAsFraction } = this.get()
+          this.set({ lengthAsFractionDeferred: lengthAsFraction })
+          stop('set lengthAsFractionDeferred')
+          requestAnimationFrame(() => this.set({ shouldAnimate: true }))
+        })
+      }, { init: false })
+    },
+    data: () => ({
+      shouldAnimate: false,
+      lengthAsFractionDeferred: 0,
+      style: ''
+    }),
+    store: () => store,
+    computed: {
+      lengthAsFraction: ({ length, max }) => {
+        // We don't need to update the gauge for every decimal point, so round it to the nearest 0.02
+        const int = Math.round(Math.min(max, length) / max * 100)
+        return (int - (int % 2)) / 100
+      },
+      computedStyle: ({ style, lengthAsFractionDeferred }) => `transform: scaleX(${lengthAsFractionDeferred}); ${style}`
+    },
+    methods: {
+      observe
+    }
+  }
+</script>

src/routes/_components/LengthIndicator.html

@@ -0,0 +1,56 @@
+<span class="length-indicator {overLimit ? 'over-char-limit' : ''}"
+      aria-label={lengthLabel}
+      {style}
+>{lengthToDisplayDeferred}</span>
+<style>
+  .length-indicator {
+    color: var(--length-indicator-color);
+    font-size: 1.3em;
+  }
+
+  .length-indicator.over-char-limit {
+    color: var(--warning-color);
+  }
+</style>
+<script>
+  import { mark, stop } from '../_utils/marks'
+  import { store } from '../_store/store'
+  import { observe } from 'svelte-extras'
+  import { throttleTimer } from '../_utils/throttleTimer'
+
+  const updateDisplayedLength = process.browser && throttleTimer(requestAnimationFrame)
+
+  export default {
+    oncreate () {
+      const { lengthToDisplay } = this.get()
+      this.set({ lengthToDisplayDeferred: lengthToDisplay })
+      // perf improvement for keyboard input latency
+      this.observe('lengthToDisplay', () => {
+        updateDisplayedLength(() => {
+          mark('set lengthToDisplayDeferred')
+          const { lengthToDisplay } = this.get()
+          this.set({ lengthToDisplayDeferred: lengthToDisplay })
+          stop('set lengthToDisplayDeferred')
+        })
+      }, { init: false })
+    },
+    data: () => ({
+      lengthToDisplayDeferred: 0,
+      style: ''
+    }),
+    store: () => store,
+    computed: {
+      lengthToDisplay: ({ length, max }) => max - length,
+      lengthLabel: ({ overLimit, lengthToDisplayDeferred }) => {
+        if (overLimit) {
+          return `${lengthToDisplayDeferred} characters over limit`
+        } else {
+          return `${lengthToDisplayDeferred} characters remaining`
+        }
+      }
+    },
+    methods: {
+      observe
+    }
+  }
+</script>

src/routes/_components/compose/ComposeLengthGauge.html

@@ -1,57 +1,16 @@
-<div class="compose-box-length-gauge {shouldAnimate ? 'should-animate' : ''}  {overLimit ? 'over-char-limit' : ''}"
-     style="transform: scaleX({lengthAsFractionDeferred});"
-     aria-hidden="true"
-></div>
-<style>
-  .compose-box-length-gauge {
-    grid-area: gauge;
-    margin: 0 0 5px 5px;
-    height: 2px;
-    background: var(--main-theme-color);
-    transform-origin: left;
-  }
-  .compose-box-length-gauge.should-animate {
-    transition: transform 0.2s linear;
-  }
-  .compose-box-length-gauge.over-char-limit {
-    background: var(--warning-color);
-  }
-</style>
+<LengthGauge style="grid-area: gauge; margin: 0 0 5px 5px;"
+       {length}
+       {overLimit}
+       max={$maxStatusChars}
+/>
 <script>
-  import { mark, stop } from '../../_utils/marks'
+  import LengthGauge from '../LengthGauge.html'
   import { store } from '../../_store/store'
-  import { scheduleIdleTask } from '../../_utils/scheduleIdleTask'
-  import { observe } from 'svelte-extras'
 
   export default {
-    oncreate () {
-      const { lengthAsFraction } = this.get()
-      this.set({ lengthAsFractionDeferred: lengthAsFraction })
-      // perf improvement for keyboard input latency
-      this.observe('lengthAsFraction', () => {
-        scheduleIdleTask(() => {
-          mark('set lengthAsFractionDeferred')
-          const { lengthAsFraction } = this.get()
-          this.set({ lengthAsFractionDeferred: lengthAsFraction })
-          stop('set lengthAsFractionDeferred')
-          requestAnimationFrame(() => this.set({ shouldAnimate: true }))
-        })
-      }, { init: false })
+    components: {
+      LengthGauge
     },
-    data: () => ({
-      shouldAnimate: false,
-      lengthAsFractionDeferred: 0
-    }),
-    store: () => store,
-    computed: {
-      lengthAsFraction: ({ length, $maxStatusChars }) => {
-        // We don't need to update the gauge for every decimal point, so round it to the nearest 0.02
-        const int = Math.round(Math.min($maxStatusChars, length) / $maxStatusChars * 100)
-        return (int - (int % 2)) / 100
-      }
-    },
-    methods: {
-      observe
-    }
+    store: () => store
   }
-</script>
+</script>

src/routes/_components/compose/ComposeLengthIndicator.html

@@ -1,56 +1,17 @@
-<span class="compose-box-length {overLimit ? 'over-char-limit' : ''}"
-      aria-label={lengthLabel}>
-      {lengthToDisplayDeferred}
-    </span>
-<style>
-  .compose-box-length {
-    grid-area: length;
-    justify-self: right;
-    color: var(--length-indicator-color);
-    font-size: 1.3em;
-    align-self: center;
-  }
-
-  .compose-box-length.over-char-limit {
-    color: var(--warning-color);
-  }
-</style>
+<LengthIndicator
+  {length}
+  {overLimit}
+  max={$maxStatusChars}
+  style="grid-area: length; justify-self: right; align-self: center;"
+/>
 <script>
-  import { mark, stop } from '../../_utils/marks'
   import { store } from '../../_store/store'
-  import { scheduleIdleTask } from '../../_utils/scheduleIdleTask'
-  import { observe } from 'svelte-extras'
+  import LengthIndicator from '../LengthIndicator.html'
 
   export default {
-    oncreate () {
-      const { lengthToDisplay } = this.get()
-      this.set({ lengthToDisplayDeferred: lengthToDisplay })
-      // perf improvement for keyboard input latency
-      this.observe('lengthToDisplay', () => {
-        scheduleIdleTask(() => {
-          mark('set lengthToDisplayDeferred')
-          const { lengthToDisplay } = this.get()
-          this.set({ lengthToDisplayDeferred: lengthToDisplay })
-          stop('set lengthToDisplayDeferred')
-        })
-      }, { init: false })
-    },
-    data: () => ({
-      lengthToDisplayDeferred: 0
-    }),
     store: () => store,
-    computed: {
-      lengthToDisplay: ({ length, $maxStatusChars }) => $maxStatusChars - length,
-      lengthLabel: ({ overLimit, lengthToDisplayDeferred }) => {
-        if (overLimit) {
-          return `${lengthToDisplayDeferred} characters over limit`
-        } else {
-          return `${lengthToDisplayDeferred} characters remaining`
-        }
-      }
-    },
-    methods: {
-      observe
+    components: {
+      LengthIndicator
     }
   }
 </script>

src/routes/_components/compose/ComposeMediaItem.html

@@ -26,7 +26,6 @@
            placeholder="Description"
            ref:textarea
            bind:value=rawText
-           maxlength="420"
     ></textarea>
     <label for="compose-media-input-{uuid}" class="sr-only">
       Describe for the visually impaired (image, video) or auditorily impaired (audio, video)

src/routes/_components/dialog/components/MediaAltEditor.html

@@ -5,15 +5,26 @@
     placeholder="Description"
     ref:textarea
     bind:value=rawText
-    maxlength="420"
   ></textarea>
   <label for="the-media-alt-input-{realm}-{index}" class="sr-only">
     Describe for the visually impaired
   </label>
+  <LengthGauge
+    {length}
+    {overLimit}
+    max={mediaAltCharLimit}
+  />
+  <LengthIndicator
+    {length}
+    {overLimit}
+    max={mediaAltCharLimit}
+    style="width: 100%; text-align: right;"
+  />
 </div>
 <style>
   .media-alt-editor {
     display: flex;
+    flex-direction: column;
   }
   .media-alt-input {
     padding: 5px;
@@ -42,6 +53,10 @@
   import { throttleTimer } from '../../../_utils/throttleTimer'
   import { get } from '../../../_utils/lodash-lite'
   import { store } from '../../../_store/store'
+  import { MEDIA_ALT_CHAR_LIMIT } from '../../../_static/media'
+  import LengthGauge from '../../LengthGauge.html'
+  import LengthIndicator from '../../LengthIndicator.html'
+  import { length } from 'stringz'
 
   const updateRawTextInStore = throttleTimer(requestPostAnimationFrame)
 
@@ -56,8 +71,13 @@
     },
     store: () => store,
     data: () => ({
-      rawText: ''
+      rawText: '',
+      mediaAltCharLimit: MEDIA_ALT_CHAR_LIMIT
     }),
+    computed: {
+      length: ({ rawText }) => length(rawText || ''),
+      overLimit: ({ mediaAltCharLimit, length }) => length > mediaAltCharLimit
+    },
     methods: {
       observe,
       setupSyncFromStore () {
@@ -99,6 +119,10 @@
       measure () {
         autosize.update(this.refs.textarea)
       }
+    },
+    components: {
+      LengthGauge,
+      LengthIndicator
     }
   }
 </script>

src/routes/_static/media.js

@@ -8,3 +8,5 @@ export const mediaAccept = '.jpg,.jpeg,.png,.gif,.webm,.mp4,.m4v,.mov,image/jpeg
   'image/gif,video/webm,video/mp4,video/quicktime,' +
   // some instances allow audio uploads
   'audio/mpeg,audio/mp4,audio/vnd.wav,audio/wav,audio/x-wav,audio/x-wave,audio/ogg'
+
+export const MEDIA_ALT_CHAR_LIMIT = 420

tests/utils.js

@@ -19,7 +19,7 @@ export const formError = $('.form-error-user-error')
 export const composeInput = $('.compose-box-input')
 export const composeContentWarning = $('.content-warning-input')
 export const composeButton = $('.compose-box-button')
-export const composeLengthIndicator = $('.compose-box-length')
+export const composeLengthIndicator = $('.length-indicator')
 export const emojiButton = $('.compose-box-toolbar button:first-child')
 export const mediaButton = $('.compose-box-toolbar button:nth-child(2)')
 export const pollButton = $('.compose-box-toolbar button:nth-child(3)')