From 20df811311302f9d6192c42ef44ada7cd0b840e0 Mon Sep 17 00:00:00 2001
From: Roy Schut <roy@videodock.com>
Date: Thu, 24 Oct 2024 16:46:20 +0200
Subject: [PATCH] refactor(home): animation optimisation

---
 .../FeaturedShelf/FeaturedShelf.module.scss   |  4 +-
 .../FeaturedShelf/FeaturedShelf.tsx           | 60 ++++++++-----------
 2 files changed, 28 insertions(+), 36 deletions(-)

diff --git a/packages/ui-react/src/components/FeaturedShelf/FeaturedShelf.module.scss b/packages/ui-react/src/components/FeaturedShelf/FeaturedShelf.module.scss
index 784e711d0..cb4625270 100644
--- a/packages/ui-react/src/components/FeaturedShelf/FeaturedShelf.module.scss
+++ b/packages/ui-react/src/components/FeaturedShelf/FeaturedShelf.module.scss
@@ -108,8 +108,8 @@
 
   @include responsive.mobile-and-small-tablet() {
     height: calc(67vh + 56px);
-    -webkit-mask-image: linear-gradient(to top, #0000 0, rgba(0,0,0,0.2) 50%, rgba(0,0,0,0.8) 80%);
-    mask-image: linear-gradient(to top, #0000 0, rgba(0,0,0,0.2) 50%, rgba(0,0,0,0.8) 80%);
+    -webkit-mask-image: linear-gradient(to top, #0000 0, rgba(0,0,0,0.2) 50%, rgba(0,0,0,0.8) 75%, rgba(0,0,0,0.5) 90%);
+    mask-image: linear-gradient(to top, #0000 0, rgba(0,0,0,0.2) 50%, rgba(0,0,0,0.8) 75%, rgba(0,0,0,0.5) 90%);
   }
 }
 .image {
diff --git a/packages/ui-react/src/components/FeaturedShelf/FeaturedShelf.tsx b/packages/ui-react/src/components/FeaturedShelf/FeaturedShelf.tsx
index 21e4047c3..acb1de7a6 100644
--- a/packages/ui-react/src/components/FeaturedShelf/FeaturedShelf.tsx
+++ b/packages/ui-react/src/components/FeaturedShelf/FeaturedShelf.tsx
@@ -61,69 +61,61 @@ const FeaturedShelf = ({ playlist, loading = false, error = null }: Props) => {
   const slideLeft = () => slideTo(index - 1);
   const slideRight = () => slideTo(index + 1);
 
-  const transitioningRef = React.useRef(false);
+  const handlingTransitionEnd = React.useRef(false);
 
   // Background animation takes longest, so it leads our animation flow
   const handleBackgroundAnimationEnd: TransitionEventHandler = () => {
-    if (transitioningRef.current) return;
+    if (handlingTransitionEnd.current) return;
     if (animation?.phase !== 'start') return;
 
-    transitioningRef.current = true;
-    setAnimation((current) => ({ ...current, phase: 'end' }));
+    handlingTransitionEnd.current = true; // Prevent multiple calls from different animations
+
     setTimeout(() => {
-      setAnimation(null);
-      setIndex(nextIndex);
-      transitioningRef.current = false;
-    }, 1); // Next render
+      setAnimation((current) => ({ ...current, phase: 'end' }));
+      setTimeout(() => {
+        setAnimation(null);
+        setIndex(nextIndex);
+        handlingTransitionEnd.current = false;
+      }, 1); // Next render
+    }, 250); // Difference between shortest and longest animation
   };
 
-  const item = playlist.playlist[index];
-  const leftItem = index - 1 >= 0 ? playlist.playlist[index - 1] : null;
-  const rightItem = index + 1 < playlist.playlist.length ? playlist.playlist[index + 1] : null;
-
-  // Background animation
   const isAnimating = animation?.phase === 'start' || animation?.phase === 'end';
+  const directionFactor = animation?.direction === 'left' ? 1 : animation?.direction === 'right' ? -1 : 0;
 
-  const backgroundX = {
-    left: 50,
-    right: -50,
-  };
-  const translateX = isAnimating && animation?.direction ? backgroundX[animation.direction] : 0;
+  // Background animation
+  const backgroundX = 40;
   const backgroundCurrentStyle: CSSProperties = {
-    transform: `scale(1.2) translateX(${translateX}px)`,
+    transform: `scale(1.2) translateX(${isAnimating ? backgroundX * directionFactor : 0}px)`,
     opacity: isAnimating ? 0 : 1,
-    transition: isAnimating ? 'opacity 0.3s ease-out, transform 0.3s ease-out' : 'none',
+    transition: isAnimating ? 'opacity 0.1s ease-out, transform 0.3s ease-in' : 'none',
   };
-  const translateXAlt = animation?.direction === 'left' ? -50 : animation?.direction === 'right' ? 50 : 0;
   const backgroundAltStyle: CSSProperties = {
-    transform: `scale(1.2) translateX(${animation?.phase === 'initial' ? translateXAlt : 0}px)`,
+    transform: `scale(1.2) translateX(${animation?.phase === 'initial' ? backgroundX * directionFactor * -1 : 0}px)`,
     opacity: isAnimating ? 1 : 0,
     transition: isAnimating ? 'opacity 0.3s ease-out, transform 0.3s ease-out' : 'none',
   };
 
   // Metadata animation
-  const metadataX = {
-    left: 70,
-    right: -70,
-  };
-  const distanceMetadata = 70;
-  const defaultTransition = 'opacity 0.2s ease-out, left 0.2s ease-out, right 0.2s ease-out';
-  const left = isAnimating && animation?.direction ? metadataX[animation.direction] : 0;
+  const left = 60;
   const metadataCurrentStyle: CSSProperties = {
-    left: left,
+    left: isAnimating && animation?.direction ? left * directionFactor : 0,
     opacity: isAnimating ? 0 : 1,
-    transition: isAnimating ? defaultTransition : 'none',
+    transition: isAnimating ? 'opacity 0.15s ease-out, left 0.15s ease-out' : 'none',
     pointerEvents: isAnimating ? 'none' : 'initial',
   };
 
-  const distanceAlt = animation?.direction === 'left' ? -distanceMetadata : animation?.direction === 'right' ? distanceMetadata : 0;
   const metadataAltStyle: CSSProperties = {
-    left: animation?.phase === 'initial' ? distanceAlt : 0,
+    left: animation?.phase === 'initial' ? left * directionFactor * -1 : 0,
     opacity: isAnimating ? 1 : 0,
-    transition: isAnimating ? defaultTransition : 'none',
+    transition: isAnimating ? 'opacity 0.2s ease-out, left 0.2s ease-out' : 'none',
     pointerEvents: 'none',
   };
 
+  const item = playlist.playlist[index];
+  const leftItem = index - 1 >= 0 ? playlist.playlist[index - 1] : null;
+  const rightItem = index + 1 < playlist.playlist.length ? playlist.playlist[index + 1] : null;
+
   const renderedItem = animation?.phase !== 'end' ? item : animation?.direction === 'right' ? rightItem : leftItem;
   const altItem = animation?.direction === 'right' ? rightItem : leftItem;