From 69c0cad14cec145d2369f649a2a7df6766847288 Mon Sep 17 00:00:00 2001
From: ayumi-signal <143036029+ayumi-signal@users.noreply.github.com>
Date: Mon, 2 Oct 2023 16:18:28 -0400
Subject: [PATCH] Only animate typing when viewing conversation

---
 stylesheets/_modules.scss                   | 17 ++++----
 ts/components/conversation/TypingBubble.tsx | 46 ++++++++++++++++-----
 ts/util/lint/exceptions.json                | 22 ++++++----
 3 files changed, 59 insertions(+), 26 deletions(-)

diff --git a/stylesheets/_modules.scss b/stylesheets/_modules.scss
index 884dd13c936..c8dd2507d6e 100644
--- a/stylesheets/_modules.scss
+++ b/stylesheets/_modules.scss
@@ -1384,6 +1384,11 @@ $message-padding-horizontal: 12px;
   &--with-reactions {
     padding-bottom: 15px;
   }
+
+  &--typing {
+    flex-direction: row-reverse;
+    overflow-y: clip;
+  }
 }
 
 .module-message__container-outer--typing-bubble {
@@ -1391,16 +1396,8 @@ $message-padding-horizontal: 12px;
 }
 
 .module-message__typing-avatar-container {
-  align-items: center;
-  display: flex;
   flex-direction: row-reverse;
-  justify-content: center;
-  margin-inline-end: 8px;
   overflow-y: clip;
-
-  &--with-reactions {
-    padding-bottom: 15px;
-  }
 }
 
 .module-message__typing-avatar {
@@ -2848,6 +2845,10 @@ button.module-image__border-overlay:focus {
   padding-inline: 1px;
 }
 
+.module-message__typing-animation-container .module-typing-animation {
+  width: 30px;
+}
+
 .module-typing-animation__dot {
   border-radius: 50%;
 
diff --git a/ts/components/conversation/TypingBubble.tsx b/ts/components/conversation/TypingBubble.tsx
index 555d6a680d1..98efd4e2e85 100644
--- a/ts/components/conversation/TypingBubble.tsx
+++ b/ts/components/conversation/TypingBubble.tsx
@@ -44,8 +44,8 @@ export type TypingBubblePropsType = {
 
 const SPRING_CONFIG = {
   mass: 1,
-  tension: 986,
-  friction: 64,
+  tension: 439,
+  friction: 42,
   precision: 0,
   velocity: 0,
 };
@@ -53,17 +53,15 @@ const SPRING_CONFIG = {
 const AVATAR_ANIMATION_PROPS: Record<'visible' | 'hidden', object> = {
   visible: {
     opacity: 1,
-    scale: 1,
     width: '28px',
     x: '0px',
     top: '0px',
   },
   hidden: {
     opacity: 0.5,
-    scale: 0.5,
     width: '4px', // Match value of module-message__typing-avatar margin-inline-start
     x: '14px',
-    top: '30px',
+    top: '34px',
   },
 };
 
@@ -71,6 +69,7 @@ function TypingBubbleAvatar({
   conversationId,
   contact,
   visible,
+  shouldAnimate,
   getPreferredBadge,
   onContactExit,
   showContactModal,
@@ -80,6 +79,7 @@ function TypingBubbleAvatar({
   conversationId: string;
   contact: TypingContactType | undefined;
   visible: boolean;
+  shouldAnimate: boolean;
   getPreferredBadge: PreferredBadgeSelectorType;
   onContactExit: (id: string | undefined) => void;
   showContactModal: (contactId: string, conversationId?: string) => void;
@@ -89,7 +89,9 @@ function TypingBubbleAvatar({
   const [springProps, springApi] = useSpring(
     {
       config: SPRING_CONFIG,
-      from: AVATAR_ANIMATION_PROPS[visible ? 'hidden' : 'visible'],
+      from: shouldAnimate
+        ? AVATAR_ANIMATION_PROPS[visible ? 'hidden' : 'visible']
+        : {},
       to: AVATAR_ANIMATION_PROPS[visible ? 'visible' : 'hidden'],
       onRest: () => {
         if (!visible) {
@@ -138,6 +140,7 @@ function TypingBubbleAvatar({
 function TypingBubbleGroupAvatars({
   conversationId,
   typingContactIds,
+  shouldAnimate,
   getConversation,
   getPreferredBadge,
   showContactModal,
@@ -153,6 +156,7 @@ function TypingBubbleGroupAvatars({
   | 'theme'
 > & {
   typingContactIds: ReadonlyArray<string>;
+  shouldAnimate: boolean;
 }): ReactElement {
   const [allContactsById, setAllContactsById] = useState<
     Map<string, TypingContactType>
@@ -195,7 +199,7 @@ function TypingBubbleGroupAvatars({
 
   // Avatars are rendered Right-to-Left so the leftmost avatars can render on top.
   return (
-    <div className="module-message__typing-avatar-container">
+    <div className="module-message__author-avatar-container module-message__author-avatar-container--typing">
       {typingContactsOverflowCount > 0 && (
         <div
           className="module-message__typing-avatar module-message__typing-avatar--overflow-count
@@ -228,6 +232,7 @@ function TypingBubbleGroupAvatars({
             i18n={i18n}
             theme={theme}
             visible={visibleContactIds.has(contactId)}
+            shouldAnimate={shouldAnimate}
           />
         ))}
     </div>
@@ -241,12 +246,10 @@ const OUTER_DIV_ANIMATION_PROPS: Record<'visible' | 'hidden', object> = {
 const BUBBLE_ANIMATION_PROPS: Record<'visible' | 'hidden', object> = {
   visible: {
     opacity: 1,
-    scale: 1,
     top: '0px',
   },
   hidden: {
     opacity: 0.5,
-    scale: 0.5,
     top: '30px',
   },
 };
@@ -269,13 +272,17 @@ export function TypingBubble({
     () => Object.keys(typingContactIdTimestamps),
     [typingContactIdTimestamps]
   );
+  const [shouldAnimate, setShouldAnimate] = useState(false);
+  const prevTypingContactIds = React.useRef<
+    ReadonlyArray<string> | undefined
+  >();
   const isSomeoneTyping = useMemo(
     () => typingContactIds.length > 0,
     [typingContactIds]
   );
+
   const [outerDivStyle, outerDivSpringApi] = useSpring(
     {
-      from: OUTER_DIV_ANIMATION_PROPS[isSomeoneTyping ? 'hidden' : 'visible'],
       to: OUTER_DIV_ANIMATION_PROPS[isSomeoneTyping ? 'visible' : 'hidden'],
       config: SPRING_CONFIG,
     },
@@ -283,7 +290,6 @@ export function TypingBubble({
   );
   const [typingAnimationStyle, typingAnimationSpringApi] = useSpring(
     {
-      from: BUBBLE_ANIMATION_PROPS[isSomeoneTyping ? 'hidden' : 'visible'],
       to: BUBBLE_ANIMATION_PROPS[isSomeoneTyping ? 'visible' : 'hidden'],
       config: SPRING_CONFIG,
       onRest: () => {
@@ -336,6 +342,23 @@ export function TypingBubble({
     typingContactIdTimestamps,
   ]);
 
+  // Only animate when the user observes a change in typing contacts, not when first
+  // switching to a conversation.
+  useEffect(() => {
+    if (shouldAnimate) {
+      return;
+    }
+
+    if (!prevTypingContactIds.current) {
+      prevTypingContactIds.current = typingContactIds;
+      return;
+    }
+
+    if (prevTypingContactIds.current !== typingContactIds) {
+      setShouldAnimate(true);
+    }
+  }, [shouldAnimate, typingContactIds]);
+
   if (!isVisible) {
     return null;
   }
@@ -360,6 +383,7 @@ export function TypingBubble({
           <TypingBubbleGroupAvatars
             conversationId={conversationId}
             typingContactIds={typingContactIds}
+            shouldAnimate={shouldAnimate}
             getConversation={getConversation}
             getPreferredBadge={getPreferredBadge}
             showContactModal={showContactModal}
diff --git a/ts/util/lint/exceptions.json b/ts/util/lint/exceptions.json
index 58c3ae3e44e..0077874c4c4 100644
--- a/ts/util/lint/exceptions.json
+++ b/ts/util/lint/exceptions.json
@@ -2688,6 +2688,14 @@
     "reasonCategory": "usageTrusted",
     "updated": "2022-11-03T14:21:47.456Z"
   },
+  {
+    "rule": "React-useRef",
+    "path": "ts/components/conversation/TypingBubble.tsx",
+    "line": "  const prevTypingContactIds = React.useRef<",
+    "reasonCategory": "usageTrusted",
+    "updated": "2023-09-28T21:48:57.488Z",
+    "reasonDetail": "Used to track change of typing contacts while a conversation is actively viewed."
+  },
   {
     "rule": "React-useRef",
     "path": "ts/components/conversation/WaveformScrubber.tsx",
@@ -2804,6 +2812,13 @@
     "reasonCategory": "usageTrusted",
     "updated": "2021-10-22T00:52:39.251Z"
   },
+  {
+    "rule": "React-useRef",
+    "path": "ts/hooks/useScrollLock.tsx",
+    "line": "  const onUserInterruptRef = useRef(onUserInterrupt);",
+    "reasonCategory": "usageTrusted",
+    "updated": "2023-09-19T17:05:51.321Z"
+  },
   {
     "rule": "React-useRef",
     "path": "ts/hooks/useSizeObserver.tsx",
@@ -2853,13 +2868,6 @@
     "reasonCategory": "usageTrusted",
     "updated": "2023-07-25T21:55:26.191Z"
   },
-  {
-    "rule": "React-useRef",
-    "path": "ts/hooks/useScrollLock.tsx",
-    "line": "  const onUserInterruptRef = useRef(onUserInterrupt);",
-    "reasonCategory": "usageTrusted",
-    "updated": "2023-09-19T17:05:51.321Z"
-  },
   {
     "rule": "React-useRef",
     "path": "ts/quill/formatting/menu.tsx",