From 4180e58f3b365f4fca26c7789f6689591037410d Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Thu, 8 Jul 2021 18:00:41 +0300
Subject: [PATCH] Prevent more animations when animations are turned off

---
 .../composer/ComposerEmbeddedMessage.scss     |  2 +-
 .../middle/composer/WebPagePreview.scss       |  4 +++
 src/util/fastSmoothScroll.ts                  | 13 +++++++++
 src/util/fastSmoothScrollHorizontal.ts        | 28 +++++++++++++++----
 4 files changed, 40 insertions(+), 7 deletions(-)

diff --git a/src/components/middle/composer/ComposerEmbeddedMessage.scss b/src/components/middle/composer/ComposerEmbeddedMessage.scss
index d347acf2..b5725a47 100644
--- a/src/components/middle/composer/ComposerEmbeddedMessage.scss
+++ b/src/components/middle/composer/ComposerEmbeddedMessage.scss
@@ -6,7 +6,7 @@
     height: 0 !important;
   }
 
-  body.animation-level-0 {
+  body.animation-level-0 & {
     transition: none !important;
   }
 
diff --git a/src/components/middle/composer/WebPagePreview.scss b/src/components/middle/composer/WebPagePreview.scss
index dea50d52..4cd7e487 100644
--- a/src/components/middle/composer/WebPagePreview.scss
+++ b/src/components/middle/composer/WebPagePreview.scss
@@ -2,6 +2,10 @@
   height: 2.625rem;
   transition: height 150ms ease-out, opacity 150ms ease-out;
 
+  body.animation-level-0 & {
+    transition: none !important;
+  }
+
   &:not(.open) {
     height: 0 !important;
   }
diff --git a/src/util/fastSmoothScroll.ts b/src/util/fastSmoothScroll.ts
index cac15b06..c860819d 100644
--- a/src/util/fastSmoothScroll.ts
+++ b/src/util/fastSmoothScroll.ts
@@ -1,5 +1,8 @@
+import { getGlobal } from '../lib/teact/teactn';
+
 import { FocusDirection } from '../types';
 
+import { ANIMATION_LEVEL_MIN } from '../config';
 import { dispatchHeavyAnimationEvent } from '../hooks/useHeavyAnimationCheck';
 import { fastRaf } from './schedulers';
 import { animateSingle } from './animation';
@@ -50,6 +53,10 @@ export default function fastSmoothScroll(
     container.scrollTop = Math.max(0, offsetTop - maxDistance);
   }
 
+  if (getGlobal().settings.byKey.animationLevel === ANIMATION_LEVEL_MIN) {
+    forceDuration = 0;
+  }
+
   isAnimating = true;
   fastRaf(() => {
     scrollWithJs(container, element, position, margin, forceDuration, forceCurrentContainerHeight);
@@ -102,6 +109,12 @@ function scrollWithJs(
   }
 
   const target = container.scrollTop + path;
+
+  if (forceDuration === 0) {
+    container.scrollTop = target;
+    return;
+  }
+
   const duration = forceDuration || (
     MIN_JS_DURATION + (Math.abs(path) / MAX_DISTANCE) * (MAX_JS_DURATION - MIN_JS_DURATION)
   );
diff --git a/src/util/fastSmoothScrollHorizontal.ts b/src/util/fastSmoothScrollHorizontal.ts
index 19261359..e8a87dc1 100644
--- a/src/util/fastSmoothScrollHorizontal.ts
+++ b/src/util/fastSmoothScrollHorizontal.ts
@@ -1,21 +1,31 @@
+import { getGlobal } from '../lib/teact/teactn';
+
 import { fastRaf } from './schedulers';
 import { animate } from './animation';
 import { IS_IOS } from './environment';
+import { ANIMATION_LEVEL_MIN } from '../config';
 
-const DURATION = 300;
+const DEFAULT_DURATION = 300;
+
+export default function fastSmoothScrollHorizontal(container: HTMLElement, left: number, duration = DEFAULT_DURATION) {
+  if (getGlobal().settings.byKey.animationLevel === ANIMATION_LEVEL_MIN) {
+    duration = 0;
+  }
 
-export default function fastSmoothScrollHorizontal(container: HTMLElement, left: number) {
   // Native way seems to be smoother in Chrome
   if (!IS_IOS) {
-    container.scrollTo({ left, behavior: 'smooth' });
+    container.scrollTo({
+      left,
+      ...(duration && { behavior: 'smooth' }),
+    });
   } else {
     fastRaf(() => {
-      scrollWithJs(container, left);
+      scrollWithJs(container, left, duration);
     });
   }
 }
 
-function scrollWithJs(container: HTMLElement, left: number) {
+function scrollWithJs(container: HTMLElement, left: number, duration: number) {
   const { scrollLeft, offsetWidth: containerWidth, scrollWidth } = container;
   let path = left - scrollLeft;
 
@@ -28,10 +38,16 @@ function scrollWithJs(container: HTMLElement, left: number) {
   }
 
   const target = container.scrollLeft + path;
+
+  if (duration === 0) {
+    container.scrollTop = target;
+    return;
+  }
+
   const startAt = Date.now();
 
   animate(() => {
-    const t = Math.min((Date.now() - startAt) / DURATION, 1);
+    const t = Math.min((Date.now() - startAt) / duration, 1);
 
     const currentPath = path * (1 - transition(t));
     container.scrollLeft = Math.round(target - currentPath);