From 7875925be09d4a851edcea48c0f897d139398264 Mon Sep 17 00:00:00 2001
From: Nolan Lawson <nolan@nolanlawson.com>
Date: Fri, 13 Aug 2021 17:40:03 -0700
Subject: [PATCH] fix: support RTL direction (#213)

* fix: support RTL direction

fixes #212

* fix: fix for old Safari

* fix: remove test page rtl
---
 src/picker/components/Picker/Picker.html |  9 +++---
 src/picker/components/Picker/Picker.js   | 40 +++++++++++++-----------
 src/picker/styles/picker.scss            | 11 +++++--
 test/adhoc/index.html                    |  2 ++
 4 files changed, 36 insertions(+), 26 deletions(-)

diff --git a/src/picker/components/Picker/Picker.html b/src/picker/components/Picker/Picker.html
index f0dec94..3ad9d73 100644
--- a/src/picker/components/Picker/Picker.html
+++ b/src/picker/components/Picker/Picker.html
@@ -77,7 +77,7 @@
   </div>
   <div class="nav"
        role="tablist"
-       style="grid-template-columns: repeat({groups.length}, 1fr);"
+       style="grid-template-columns: repeat({groups.length}, 1fr)"
        aria-label={i18n.categoriesLabel}
        on:keydown={onNavKeydown}>
     {#each groups as group (group.id)}
@@ -95,7 +95,8 @@
     {/each}
   </div>
   <div class="indicator-wrapper">
-    <div class="indicator" style={indicatorStyle}>
+    <div class="indicator"
+         style="transform: translateX({(isRtl ? -1 : 1) * currentGroupIndex * 100}%)">
     </div>
   </div>
 
@@ -114,7 +115,7 @@
        on:click={onEmojiClick}
        bind:this={tabpanelElement}
   >
-    <div use:calculateEmojiGridWidth>
+    <div use:calculateEmojiGridStyle>
       {#each currentEmojisWithCategories as emojiWithCategory, i (emojiWithCategory.category)}
         <div
           id="menu-label-{i}"
@@ -161,7 +162,7 @@
   <div class="favorites emoji-menu {message ? 'gone': ''}"
        role="menu"
        aria-label={i18n.favoritesLabel}
-       style="padding-right: {scrollbarWidth}px;"
+       style="padding-inline-end: {scrollbarWidth}px"
        on:click={onEmojiClick}
        data-testid="favorites">
     <!-- The reason the emoji logic below is largely duplicated is because it turns out we get a smaller
diff --git a/src/picker/components/Picker/Picker.js b/src/picker/components/Picker/Picker.js
index 98d2d9a..7e204a3 100644
--- a/src/picker/components/Picker/Picker.js
+++ b/src/picker/components/Picker/Picker.js
@@ -42,7 +42,6 @@ let tabpanelElement
 let searchMode = false // eslint-disable-line no-unused-vars
 let activeSearchItem = -1
 let message // eslint-disable-line no-unused-vars
-let indicatorStyle = '' // eslint-disable-line no-unused-vars
 let skinTonePickerExpanded = false
 let skinTonePickerExpandedAfterAnimation = false // eslint-disable-line no-unused-vars
 let skinToneDropdown
@@ -55,6 +54,7 @@ let skinTones = []
 let currentFavorites = [] // eslint-disable-line no-unused-vars
 let defaultFavoriteEmojis
 let numColumns = DEFAULT_NUM_COLUMNS
+let isRtl = false
 let scrollbarWidth = 0 // eslint-disable-line no-unused-vars
 let currentGroupIndex = 0
 let groups = defaultGroups
@@ -221,22 +221,31 @@ $: {
 // 1) Re-calculate the --num-columns var because it may have changed
 // 2) Re-calculate the scrollbar width because it may have changed
 //   (i.e. because the number of items changed)
+// 3) Re-calculate whether we're in RTL mode or not.
+//
+// The benefit of doing this in one place is to align with rAF/ResizeObserver
+// and do all the calculations in one go. RTL vs LTR is not strictly width-related,
+// but since we're already reading the style here, and since it's already aligned with
+// the rAF loop, this is the most appropriate place to do it perf-wise.
 //
 
 // eslint-disable-next-line no-unused-vars
-function calculateEmojiGridWidth (node) {
+function calculateEmojiGridStyle (node) {
   return widthCalculator.calculateWidth(node, width => {
     /* istanbul ignore next */
-    const newNumColumns = process.env.NODE_ENV === 'test'
-      ? DEFAULT_NUM_COLUMNS
-      : parseInt(getComputedStyle(rootElement).getPropertyValue('--num-columns'), 10)
-    /* istanbul ignore next */
-    const parentWidth = process.env.NODE_ENV === 'test' // jsdom throws an error here occasionally
-      ? 1
-      : node.parentElement.getBoundingClientRect().width
-    const newScrollbarWidth = parentWidth - width
-    numColumns = newNumColumns
-    scrollbarWidth = newScrollbarWidth // eslint-disable-line no-unused-vars
+    if (process.env.NODE_ENV !== 'test') { // jsdom throws errors for this kind of fancy stuff
+      // read all the style/layout calculations we need to make
+      const style = getComputedStyle(rootElement)
+      const newNumColumns = parseInt(style.getPropertyValue('--num-columns'), 10)
+      const newIsRtl = style.getPropertyValue('direction') === 'rtl'
+      const parentWidth = node.parentElement.getBoundingClientRect().width
+      const newScrollbarWidth = parentWidth - width
+
+      // write to Svelte variables
+      numColumns = newNumColumns
+      scrollbarWidth = newScrollbarWidth // eslint-disable-line no-unused-vars
+      isRtl = newIsRtl // eslint-disable-line no-unused-vars
+    }
   })
 }
 
@@ -246,13 +255,6 @@ function calculateEmojiGridWidth (node) {
 
 $: currentGroup = groups[currentGroupIndex]
 
-//
-// Animate the indicator (little blue bar below category icons)
-//
-
-// eslint-disable-next-line no-unused-vars
-$: indicatorStyle = `transform: translateX(${`${currentGroupIndex * 100}%`})`
-
 //
 // Set or update the currentEmojis. Check for invalid ZWJ renderings
 // (i.e. double emoji).
diff --git a/src/picker/styles/picker.scss b/src/picker/styles/picker.scss
index 5d2053a..076f93d 100644
--- a/src/picker/styles/picker.scss
+++ b/src/picker/styles/picker.scss
@@ -21,7 +21,7 @@ $skintoneZIndex3: 3;
 
 .skintone-list {
   position: absolute;
-  right: 0;
+  inset-inline-end: 0;
   top: 0;
   z-index: $skintoneZIndex2;
   overflow: visible;
@@ -41,6 +41,12 @@ $skintoneZIndex3: 3;
     transition-duration: 0.001s;
   }
 
+  // TODO: remove this when old iOS Safari drops out of usage: https://caniuse.com/css-logical-props
+  // For now, we don't support RTL in old versions of iOS
+  @supports not (inset-inline-end: 0) {
+    right: 0;
+  }
+
   &.no-animate {
     transition: none;
   }
@@ -175,12 +181,11 @@ button.emoji,
   background: var(--background);
 }
 
-
 .search-row {
   display: flex;
   align-items: center;
   position: relative;
-  padding-left: var(--emoji-padding);
+  padding-inline-start: var(--emoji-padding);
   padding-bottom: var(--emoji-padding);
 }
 
diff --git a/test/adhoc/index.html b/test/adhoc/index.html
index 75a1703..7efd2df 100644
--- a/test/adhoc/index.html
+++ b/test/adhoc/index.html
@@ -18,6 +18,8 @@
     @media screen and (max-width: 320px) {
       emoji-picker {
         width: 100%;
+        --num-columns: 6;
+        --category-emoji-size: 1.125rem;
       }
     }
     @media screen and (max-width: 240px) {