Animate raised hand button

Co-authored-by: Jamie Kyle <jamie@signal.org>

ts/components/CallScreen.tsx

@@ -75,7 +75,10 @@ import { Spinner } from './Spinner';
 import type { Props as ReactionPickerProps } from './conversation/ReactionPicker';
 import type { SmartReactionPicker } from '../state/smart/ReactionPicker';
 import { Emoji } from './emoji/Emoji';
-import { CallingRaisedHandsList } from './CallingRaisedHandsList';
+import {
+  CallingRaisedHandsList,
+  CallingRaisedHandsListButton,
+} from './CallingRaisedHandsList';
 import type { CallReactionBurstType } from './CallReactionBurst';
 import {
   CallReactionBurstProvider,
@@ -744,24 +747,15 @@ export function CallScreen({
       )}
       {remoteParticipantsElement}
       {lonelyInCallNode}
-      {raisedHands && raisedHandsCount > 0 && (
+      {raisedHands && (
         <>
-          <button
-            className="CallingRaisedHandsList__Button"
+          <CallingRaisedHandsListButton
+            i18n={i18n}
+            syncedLocalHandRaised={syncedLocalHandRaised}
+            raisedHandsCount={raisedHandsCount}
             onClick={toggleRaisedHandsList}
-            type="button"
-          >
-            <span className="CallingRaisedHandsList__ButtonIcon" />
-            {syncedLocalHandRaised ? (
-              <>
-                {i18n('icu:you')}
-                {raisedHandsCount > 1 && ` + ${String(raisedHandsCount - 1)}`}
-              </>
-            ) : (
-              raisedHandsCount
-            )}
-          </button>
-          {showRaisedHandsList && (
+          />
+          {showRaisedHandsList && raisedHandsCount > 0 && (
             <CallingRaisedHandsList
               i18n={i18n}
               onClose={() => setShowRaisedHandsList(false)}

ts/components/CallingRaisedHandsList.stories.tsx

@@ -6,8 +6,14 @@ import { times } from 'lodash';
 import { action } from '@storybook/addon-actions';
 
 import type { Meta } from '@storybook/react';
-import type { PropsType } from './CallingRaisedHandsList';
-import { CallingRaisedHandsList } from './CallingRaisedHandsList';
+import type {
+  CallingRaisedHandsListButtonPropsType,
+  PropsType,
+} from './CallingRaisedHandsList';
+import {
+  CallingRaisedHandsList,
+  CallingRaisedHandsListButton,
+} from './CallingRaisedHandsList';
 import type { ConversationType } from '../state/ducks/conversations';
 import { AvatarColors } from '../types/Colors';
 import { getDefaultConversationWithServiceId } from '../test-both/helpers/getDefaultConversation';
@@ -57,6 +63,15 @@ const createProps = (overrideProps: Partial<PropsType> = {}): PropsType => ({
   raisedHands: overrideProps.raisedHands || new Set<number>(),
 });
 
+const createPropsForButton = (
+  overrideProps: Partial<CallingRaisedHandsListButtonPropsType> = {}
+): CallingRaisedHandsListButtonPropsType => ({
+  i18n,
+  syncedLocalHandRaised: overrideProps.syncedLocalHandRaised || false,
+  raisedHandsCount: overrideProps.raisedHandsCount || 1,
+  onClick: action('on-click'),
+});
+
 export default {
   title: 'Components/CallingRaisedHandsList',
 } satisfies Meta<PropsType>;
@@ -95,3 +110,27 @@ export function Many(): JSX.Element {
   });
   return <CallingRaisedHandsList {...props} />;
 }
+
+export function Button(): JSX.Element {
+  const props = createPropsForButton();
+  return <CallingRaisedHandsListButton {...props} />;
+}
+
+export function ButtonChanging(): JSX.Element {
+  const initialProps = createPropsForButton();
+
+  const [props, setProps] = React.useState(initialProps);
+  React.useEffect(() => {
+    const interval = setInterval(() => {
+      const raisedHandsCount = Math.floor(4 * Math.random());
+      setProps(prevProps => ({
+        ...prevProps,
+        raisedHandsCount,
+        syncedLocalHandRaised: Boolean(raisedHandsCount && Math.random() > 0.5),
+      }));
+    }, 2000);
+    return () => clearInterval(interval);
+  }, []);
+
+  return <CallingRaisedHandsListButton {...props} />;
+}

ts/components/CallingRaisedHandsList.tsx

@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import React from 'react';
+import { animated, useSpring } from '@react-spring/web';
 
 import { Avatar, AvatarSize } from './Avatar';
 import { ContactName } from './conversation/ContactName';
@@ -11,6 +12,7 @@ import type { LocalizerType } from '../types/Util';
 import type { ConversationType } from '../state/ducks/conversations';
 import { ModalHost } from './ModalHost';
 import * as log from '../logging/log';
+import { usePrevious } from '../hooks/usePrevious';
 
 export type PropsType = {
   readonly i18n: LocalizerType;
@@ -133,3 +135,124 @@ export function CallingRaisedHandsList({
     </ModalHost>
   );
 }
+
+const BUTTON_OPACITY_SPRING_CONFIG = {
+  mass: 1,
+  tension: 210,
+  friction: 20,
+  precision: 0.01,
+  clamp: true,
+} as const;
+
+const BUTTON_SCALE_SPRING_CONFIG = {
+  mass: 1.5,
+  tension: 230,
+  friction: 8,
+  precision: 0.02,
+  velocity: 0.0025,
+} as const;
+
+export type CallingRaisedHandsListButtonPropsType = {
+  i18n: LocalizerType;
+  raisedHandsCount: number;
+  syncedLocalHandRaised: boolean;
+  onClick: () => void;
+};
+
+export function CallingRaisedHandsListButton({
+  i18n,
+  syncedLocalHandRaised,
+  raisedHandsCount,
+  onClick,
+}: CallingRaisedHandsListButtonPropsType): JSX.Element | null {
+  const [isVisible, setIsVisible] = React.useState(raisedHandsCount > 0);
+
+  const [opacitySpringProps, opacitySpringApi] = useSpring(
+    {
+      from: { opacity: 0 },
+      to: { opacity: 1 },
+      config: BUTTON_OPACITY_SPRING_CONFIG,
+    },
+    []
+  );
+  const [scaleSpringProps, scaleSpringApi] = useSpring(
+    {
+      from: { scale: 0.9 },
+      to: { scale: 1 },
+      config: BUTTON_SCALE_SPRING_CONFIG,
+    },
+    []
+  );
+
+  const prevRaisedHandsCount = usePrevious(raisedHandsCount, raisedHandsCount);
+  const prevSyncedLocalHandRaised = usePrevious(
+    syncedLocalHandRaised,
+    syncedLocalHandRaised
+  );
+
+  const onRestAfterAnimateOut = React.useCallback(() => {
+    if (!raisedHandsCount) {
+      setIsVisible(false);
+    }
+  }, [raisedHandsCount]);
+
+  React.useEffect(() => {
+    if (raisedHandsCount > prevRaisedHandsCount) {
+      setIsVisible(true);
+      opacitySpringApi.stop();
+      opacitySpringApi.start({ opacity: 1 });
+      scaleSpringApi.stop();
+      scaleSpringApi.start({
+        from: { scale: 0.99 },
+        to: { scale: 1 },
+        config: { velocity: 0.0025 },
+      });
+    } else if (raisedHandsCount === 0) {
+      opacitySpringApi.stop();
+      opacitySpringApi.start({
+        to: { opacity: 0 },
+        onRest: () => onRestAfterAnimateOut,
+      });
+    }
+  }, [
+    raisedHandsCount,
+    prevRaisedHandsCount,
+    opacitySpringApi,
+    scaleSpringApi,
+    onRestAfterAnimateOut,
+    setIsVisible,
+  ]);
+
+  if (!isVisible) {
+    return null;
+  }
+
+  // When the last hands are lowered, maintain the last count while fading out to prevent
+  // abrupt label changes.
+  let shownSyncedLocalHandRaised: boolean = syncedLocalHandRaised;
+  let shownRaisedHandsCount: number = raisedHandsCount;
+  if (raisedHandsCount === 0 && prevRaisedHandsCount) {
+    shownRaisedHandsCount = prevRaisedHandsCount;
+    shownSyncedLocalHandRaised = prevSyncedLocalHandRaised;
+  }
+
+  return (
+    <animated.button
+      className="CallingRaisedHandsList__Button"
+      onClick={onClick}
+      style={{ ...opacitySpringProps, ...scaleSpringProps }}
+      type="button"
+    >
+      <span className="CallingRaisedHandsList__ButtonIcon" />
+      {shownSyncedLocalHandRaised ? (
+        <>
+          {i18n('icu:you')}
+          {shownRaisedHandsCount > 1 &&
+            ` + ${String(shownRaisedHandsCount - 1)}`}
+        </>
+      ) : (
+        shownRaisedHandsCount
+      )}
+    </animated.button>
+  );
+}

ts/components/Tooltip.stories.tsx

@@ -27,16 +27,31 @@ export default {
     direction: TooltipPlacement.Top,
     sticky: false,
   },
+  decorators: [
+    (Story): JSX.Element => {
+      return (
+        <div
+          style={{
+            display: 'flex',
+            justifyContent: 'center',
+            alignItems: 'center',
+            height: '100vh',
+          }}
+        >
+          <Story />
+        </div>
+      );
+    },
+  ],
 } satisfies Meta<PropsType>;
 
 const Trigger = (
   <span
     style={{
       display: 'inline-block',
-      marginTop: 200,
-      marginBottom: 200,
-      marginInlineStart: 200,
-      marginInlineEnd: 200,
+      background: '#eee',
+      padding: 20,
+      borderRadius: 4,
     }}
   >
     Trigger