refactor: background scaling

src/context.ts

@@ -4,7 +4,6 @@ import { DrawerDirection } from './types';
 interface DrawerContextValue {
   drawerRef: React.RefObject<HTMLDivElement>;
   overlayRef: React.RefObject<HTMLDivElement>;
-  scaleBackground: (open: boolean) => void;
   onPress: (event: React.PointerEvent<HTMLDivElement>) => void;
   onRelease: (event: React.PointerEvent<HTMLDivElement>) => void;
   onDrag: (event: React.PointerEvent<HTMLDivElement>) => void;
@@ -25,12 +24,14 @@ interface DrawerContextValue {
   openProp?: boolean;
   onOpenChange?: (o: boolean) => void;
   direction?: DrawerDirection;
+  shouldScaleBackground: boolean;
+  setBackgroundColorOnScale: boolean;
+  noBodyStyles: boolean;
 }
 
 export const DrawerContext = React.createContext<DrawerContextValue>({
   drawerRef: { current: null },
   overlayRef: { current: null },
-  scaleBackground: () => {},
   onPress: () => {},
   onRelease: () => {},
   onDrag: () => {},
@@ -51,6 +52,9 @@ export const DrawerContext = React.createContext<DrawerContextValue>({
   setActiveSnapPoint: () => {},
   closeDrawer: () => {},
   direction: 'bottom',
+  shouldScaleBackground: false,
+  setBackgroundColorOnScale: true,
+  noBodyStyles: false,
 });
 
 export const useDrawerContext = () => {

src/helpers.ts

@@ -1,4 +1,4 @@
-import { DrawerDirection } from './types';
+import { AnyFunction, DrawerDirection } from './types';
 
 interface Style {
   [key: string]: string;
@@ -90,3 +90,28 @@ export function getTranslate(element: HTMLElement, direction: DrawerDirection):
 export function dampenValue(v: number) {
   return 8 * (Math.log(v + 1) - 2);
 }
+
+export function assignStyle(element: HTMLElement | null | undefined, style: Partial<CSSStyleDeclaration>) {
+  if (!element) return () => {};
+
+  const prevStyle = element.style.cssText;
+  Object.assign(element.style, style);
+
+  return () => {
+    element.style.cssText = prevStyle;
+  };
+}
+
+/**
+ * Receives functions as arguments and returns a new function that calls all.
+ */
+export function chain<T>(...fns: T[]) {
+  return (...args: T extends AnyFunction ? Parameters<T> : never) => {
+    for (const fn of fns) {
+      if (typeof fn === 'function') {
+        // @ts-ignore
+        fn(...args);
+      }
+    }
+  };
+}

src/index.tsx

@@ -20,6 +20,7 @@ import {
 } from './constants';
 import { DrawerDirection } from './types';
 import { useControllableState } from './use-controllable-state';
+import { useScaleBackground } from './use-scale-background';
 
 export interface WithFadeFromProps {
   snapPoints: (number | string)[];
@@ -330,12 +331,6 @@ export function Root({
     }
   }
 
-  React.useEffect(() => {
-    return () => {
-      scaleBackground(false);
-    };
-  }, []);
-
   React.useEffect(() => {
     function onVisualViewportChange() {
       if (!drawerRef.current) return;
@@ -397,7 +392,6 @@ export function Root({
     cancelDrag();
     onClose?.();
 
-    scaleBackground(false);
     setIsOpen(false);
 
     setTimeout(() => {
@@ -538,7 +532,6 @@ export function Root({
       });
 
       openTime.current = new Date();
-      scaleBackground(true);
     }
   }, [isOpen]);
 
@@ -555,58 +548,6 @@ export function Root({
     }
   }, [isOpen]);
 
-  function scaleBackground(open: boolean) {
-    const wrapper = document.querySelector('[data-vaul-drawer-wrapper]');
-
-    if (!wrapper || !shouldScaleBackground) return;
-
-    if (open) {
-      if (setBackgroundColorOnScale) {
-        if (!noBodyStyles) {
-          // setting original styles initially
-          set(document.body, {
-            background: document.body.style.backgroundColor || document.body.style.background,
-          });
-          // setting body styles, with cache ignored, so that we can get correct original styles in reset
-          set(
-            document.body,
-            {
-              background: 'black',
-            },
-            true,
-          );
-        }
-      }
-
-      set(wrapper, {
-        borderRadius: `${BORDER_RADIUS}px`,
-        overflow: 'hidden',
-        ...(isVertical(direction)
-          ? {
-              transform: `scale(${getScale()}) translate3d(0, calc(env(safe-area-inset-top) + 14px), 0)`,
-              transformOrigin: 'top',
-            }
-          : {
-              transform: `scale(${getScale()}) translate3d(calc(env(safe-area-inset-top) + 14px), 0, 0)`,
-              transformOrigin: 'left',
-            }),
-        transitionProperty: 'transform, border-radius',
-        transitionDuration: `${TRANSITIONS.DURATION}s`,
-        transitionTimingFunction: `cubic-bezier(${TRANSITIONS.EASE.join(',')})`,
-      });
-    } else {
-      // Exit
-      reset(wrapper, 'overflow');
-      reset(wrapper, 'transform');
-      reset(wrapper, 'borderRadius');
-      set(wrapper, {
-        transitionProperty: 'transform, border-radius',
-        transitionDuration: `${TRANSITIONS.DURATION}s`,
-        transitionTimingFunction: `cubic-bezier(${TRANSITIONS.EASE.join(',')})`,
-      });
-    }
-  }
-
   function onNestedOpenChange(o: boolean) {
     const scale = o ? (window.innerWidth - NESTED_DISPLACEMENT) / window.innerWidth : 1;
     const y = o ? -NESTED_DISPLACEMENT : 0;
@@ -683,7 +624,6 @@ export function Root({
           setActiveSnapPoint,
           drawerRef,
           overlayRef,
-          scaleBackground,
           onOpenChange,
           onPress,
           onRelease,
@@ -700,6 +640,9 @@ export function Root({
           modal,
           snapPointsOffset,
           direction,
+          shouldScaleBackground,
+          setBackgroundColorOnScale,
+          noBodyStyles,
         }}
       >
         {children}
@@ -755,7 +698,8 @@ export const Content = React.forwardRef<HTMLDivElement, ContentProps>(function (
   const pointerStartRef = React.useRef<{ x: number; y: number } | null>(null);
   const wasBeyondThePointRef = React.useRef(false);
   const hasSnapPoints = snapPoints && snapPoints.length > 0;
-
+  useScaleBackground();
+
   const isDeltaInDirection = (delta: { x: number; y: number }, direction: DrawerDirection, threshold = 0) => {
     if (wasBeyondThePointRef.current) return true;
 

src/types.ts

@@ -3,3 +3,5 @@ export interface SnapPoint {
   fraction: number;
   height: number;
 }
+
+export type AnyFunction = (...args: any) => any;

src/use-scale-background.ts

@@ -0,0 +1,51 @@
+import React from 'react';
+import { useDrawerContext } from './context';
+import { assignStyle, chain, isVertical } from './helpers';
+import { BORDER_RADIUS, TRANSITIONS, WINDOW_TOP_OFFSET } from './constants';
+
+const noop = () => () => {};
+
+export function useScaleBackground() {
+  const { direction, isOpen, shouldScaleBackground, setBackgroundColorOnScale, noBodyStyles } = useDrawerContext();
+  const timeoutIdRef = React.useRef<number | null>(null);
+
+  function getScale() {
+    return (window.innerWidth - WINDOW_TOP_OFFSET) / window.innerWidth;
+  }
+
+  React.useEffect(() => {
+    if (isOpen && shouldScaleBackground) {
+      if (timeoutIdRef.current) clearTimeout(timeoutIdRef.current);
+      const wrapper = document.querySelector('[data-vaul-drawer-wrapper]') as HTMLElement;
+
+      const bodyAndWrapperCleanup = chain(
+        setBackgroundColorOnScale && !noBodyStyles ? assignStyle(document.body, { background: 'black' }) : noop,
+        assignStyle(wrapper, {
+          transformOrigin: isVertical(direction) ? 'top' : 'left',
+          transitionProperty: 'transform, border-radius',
+          transitionDuration: `${TRANSITIONS.DURATION}s`,
+          transitionTimingFunction: `cubic-bezier(${TRANSITIONS.EASE.join(',')})`,
+        }),
+      );
+
+      const wrapperStylesCleanup = assignStyle(wrapper, {
+        borderRadius: `${BORDER_RADIUS}px`,
+        overflow: 'hidden',
+        ...(isVertical(direction)
+          ? {
+              transform: `scale(${getScale()}) translate3d(0, calc(env(safe-area-inset-top) + 14px), 0)`,
+            }
+          : {
+              transform: `scale(${getScale()}) translate3d(calc(env(safe-area-inset-top) + 14px), 0, 0)`,
+            }),
+      });
+
+      return () => {
+        wrapperStylesCleanup();
+        timeoutIdRef.current = window.setTimeout(() => {
+          bodyAndWrapperCleanup();
+        }, TRANSITIONS.DURATION * 1000);
+      };
+    }
+  }, [isOpen, shouldScaleBackground]);
+}