feat: support inverted horizontal scrolling for right-to-left locales (…

…#787)

docs/api/virtualizer.md

@@ -227,6 +227,14 @@ This option allows you to specify the duration to wait after the last scroll eve
 
 The implementation of this option is driven by the need for a reliable mechanism to handle scrolling behavior across different browsers. Until all browsers uniformly support the scrollEnd event.
 
+### `isRtl`
+
+```tsx
+isRtl: boolean
+```
+
+Whether to invert horizontal scrolling to support right-to-left language locales.
+
 ## Virtualizer Instance
 
 The following properties and methods are available on the virtualizer instance:

packages/virtual-core/src/index.ts

@@ -156,7 +156,10 @@ export const observeElementOffset = <T extends Element>(
       )
 
   const createHandler = (isScrolling: boolean) => () => {
-    offset = element[instance.options.horizontal ? 'scrollLeft' : 'scrollTop']
+    const { horizontal, isRtl } = instance.options
+    offset = horizontal
+      ? element['scrollLeft'] * ((isRtl && -1) || 1)
+      : element['scrollTop']
     fallback()
     cb(offset, isScrolling)
   }
@@ -320,6 +323,7 @@ export interface VirtualizerOptions<
   lanes?: number
   isScrollingResetDelay?: number
   enabled?: boolean
+  isRtl?: boolean
 }
 
 export class Virtualizer<
@@ -405,6 +409,7 @@ export class Virtualizer<
       lanes: 1,
       isScrollingResetDelay: 150,
       enabled: true,
+      isRtl: false,
       ...opts,
     }
   }