Add "sound waves" to transparent spotlight tiles

To indicate when the user is speaking.

src/tile/MediaView.module.css

@@ -51,6 +51,54 @@ Please see LICENSE in the repository root for full details.
   background-color: var(--video-tile-background);
 }
 
+.waves {
+  transition: opacity ease 0.3s;
+}
+
+.waves[data-visible="true"] {
+  opacity: 1;
+}
+
+.waves[data-visible="false"] {
+  opacity: 0;
+
+  @media not (prefers-reduced-motion) {
+    .wave {
+      transform: translate(-50%, -50%) scale(0.9);
+    }
+  }
+}
+
+.wave {
+  border: var(--cpd-border-width-1) solid var(--cpd-color-alpha-gray-300);
+  transition: transform ease 0.2s;
+}
+
+.wave,
+.speakingBorder {
+  border-radius: var(--cpd-radius-pill-effect);
+  position: absolute;
+  top: 50%;
+  left: 50%;
+  transform: translate(-50%, -50%);
+}
+
+.speakingBorder {
+  background:
+    radial-gradient(#0467dd, #0bc491),
+    linear-gradient(0deg, #0467dd 0%, #0bc491 100%);
+  background-blend-mode: overlay, normal;
+  outline: var(--cpd-border-width-4) solid var(--cpd-color-bg-canvas-default);
+
+  &::after {
+    content: "";
+    position: absolute;
+    inset: var(--cpd-border-width-2);
+    border-radius: var(--cpd-radius-pill-effect);
+    background: var(--cpd-color-bg-canvas-default);
+  }
+}
+
 .avatar {
   position: absolute;
   top: 50%;
@@ -73,6 +121,35 @@ unconditionally select the container so we can use cqmin units */
     inline-size: 50cqmin;
     block-size: 50cqmin;
   }
+
+  .waves + .avatar {
+    /* Make the avatar slightly smaller to accommodate sound waves, if present */
+    inline-size: 38cqmin;
+    block-size: 38cqmin;
+  }
+
+  .wave:nth-child(1) {
+    inline-size: calc(38cqmin + var(--cpd-space-5x) + 3 * var(--cpd-space-10x));
+    block-size: calc(38cqmin + var(--cpd-space-5x) + 3 * var(--cpd-space-10x));
+    background: var(--cpd-color-alpha-gray-200);
+  }
+
+  .wave:nth-child(2) {
+    inline-size: calc(38cqmin + var(--cpd-space-5x) + 2 * var(--cpd-space-10x));
+    block-size: calc(38cqmin + var(--cpd-space-5x) + 2 * var(--cpd-space-10x));
+    background: var(--cpd-color-alpha-gray-300);
+  }
+
+  .wave:nth-child(3) {
+    inline-size: calc(38cqmin + var(--cpd-space-5x) + var(--cpd-space-10x));
+    block-size: calc(38cqmin + var(--cpd-space-5x) + var(--cpd-space-10x));
+    background: var(--cpd-color-alpha-gray-400);
+  }
+
+  .speakingBorder {
+    inline-size: calc(38cqmin + var(--cpd-space-3x));
+    block-size: calc(38cqmin + var(--cpd-space-3x));
+  }
 }
 
 .avatar > img {

src/tile/MediaView.tsx

@@ -34,6 +34,7 @@ interface Props extends ComponentProps<typeof animated.div> {
   video: TrackReferenceOrPlaceholder | undefined;
   videoFit: "cover" | "contain";
   mirror: boolean;
+  soundWaves?: boolean;
   userId: string;
   videoEnabled: boolean;
   unencryptedWarning: boolean;
@@ -66,6 +67,7 @@ export const MediaView: FC<Props> = ({
   video,
   videoFit,
   mirror,
+  soundWaves,
   userId,
   videoEnabled,
   unencryptedWarning,
@@ -92,7 +94,10 @@ export const MediaView: FC<Props> = ({
   const [handRaiseTimerVisible] = useSetting(showHandRaisedTimer);
   const [showConnectionStats] = useSetting(showConnectionStatsSetting);
 
-  const avatarSize = Math.round(Math.min(targetWidth, targetHeight) / 2);
+  const avatarSize = Math.round(
+    Math.min(targetWidth, targetHeight) *
+      (soundWaves === undefined ? 0.5 : 0.38),
+  );
 
   const warnings = unencryptedWarning && (
     <Tooltip
@@ -124,6 +129,14 @@ export const MediaView: FC<Props> = ({
       {...props}
     >
       <div className={styles.bg}>
+        {soundWaves !== undefined && (
+          <div className={styles.waves} data-visible={soundWaves}>
+            <div className={styles.wave} />
+            <div className={styles.wave} />
+            <div className={styles.wave} />
+            <div className={styles.speakingBorder} />
+          </div>
+        )}
         <Avatar
           id={userId}
           name={displayName}

src/tile/SpotlightTile.tsx

@@ -79,6 +79,7 @@ interface SpotlightMemberMediaItemBaseProps extends SpotlightItemBaseProps {
 interface SpotlightUserMediaItemBaseProps extends SpotlightMemberMediaItemBaseProps {
   videoFit: "contain" | "cover";
   videoEnabled: boolean;
+  soundWaves: boolean | undefined;
 }
 
 interface SpotlightLocalUserMediaItemProps extends SpotlightUserMediaItemBaseProps {
@@ -121,6 +122,7 @@ const SpotlightUserMediaItem: FC<SpotlightUserMediaItemProps> = ({
 }) => {
   const videoFit = useBehavior(vm.videoFit$);
   const videoEnabled = useBehavior(vm.videoEnabled$);
+  const speaking = useBehavior(vm.speaking$);
 
   // Whenever target bounds change, inform the viewModel
   useEffect(() => {
@@ -133,6 +135,7 @@ const SpotlightUserMediaItem: FC<SpotlightUserMediaItemProps> = ({
     RefAttributes<HTMLDivElement> = {
     videoFit,
     videoEnabled,
+    soundWaves: props.bgStyle === "transparent" ? speaking : undefined,
     targetWidth,
     targetHeight,
     ...props,