Remove x,y from measureParentSize return type

measureParentSize uses a self-relative measureLayout call
(view.measureLayout(view, cb)) to get the view's width and height.
The x,y values from this call are always (0,0) on Paper and web since
a view's position relative to itself is the origin. The downstream
firstItemOffset calculation subtracted outerViewLayout.x/y which was
always a no-op.

Remove x,y from the return type (Layout -> Size), drop the dead
subtractions in RecyclerView, and rename outerViewLayout to
outerViewSize to reflect what it actually contains.

Co-Authored-By: Claude Sonnet 4.5 (1M context) <noreply@anthropic.com>

Author: 2 people

src/__tests__/RecyclerView.test.tsx

@@ -14,8 +14,6 @@ jest.mock("../recyclerview/utils/measureLayout", () => {
   return {
     ...originalModule,
     measureParentSize: jest.fn().mockImplementation(() => ({
-      x: 0,
-      y: 0,
       width: 399,
       height: 899,
     })),

src/recyclerview/RecyclerView.tsx

@@ -157,29 +157,30 @@ const RecyclerViewComponent = <T,>(
    */
   useLayoutEffect(() => {
     if (internalViewRef.current && firstChildViewRef.current) {
-      // Measure the outer and inner container layouts
-      const outerViewLayout = measureParentSize(internalViewRef.current);
+      // Measure the outer container size and inner container layout
+      const outerViewSize = measureParentSize(internalViewRef.current);
       const firstChildViewLayout = measureFirstChildLayout(
         firstChildViewRef.current,
         internalViewRef.current
       );
 
-      containerViewSizeRef.current = outerViewLayout;
+      containerViewSizeRef.current = outerViewSize;
 
-      // Calculate offset of first item
+      // firstChildViewLayout is already relative to the outer container,
+      // so its x/y directly gives the first item offset.
       const firstItemOffset = horizontal
-        ? firstChildViewLayout.x - outerViewLayout.x
-        : firstChildViewLayout.y - outerViewLayout.y;
+        ? firstChildViewLayout.x
+        : firstChildViewLayout.y;
 
       // Update the RecyclerView manager with window dimensions
       recyclerViewManager.updateLayoutParams(
         {
           width: horizontal
-            ? outerViewLayout.width
+            ? outerViewSize.width
             : firstChildViewLayout.width,
           height: horizontal
             ? firstChildViewLayout.height
-            : outerViewLayout.height,
+            : outerViewSize.height,
         },
         isHorizontalRTL && recyclerViewManager.hasLayout()
           ? firstItemOffset -

src/recyclerview/utils/measureLayout.ts

@@ -7,6 +7,11 @@ interface Layout {
   height: number;
 }
 
+interface Size {
+  width: number;
+  height: number;
+}
+
 /**
  * Measures the layout of a view relative to itselft.
  * Using measure wasn't returing accurate values but this workaround does.
@@ -89,14 +94,15 @@ export function roundOffPixel(value: number): number {
 }
 
 /**
- * Specific method for easier mocking
- * Measures the layout of parent of RecyclerView
- * Returns the x, y coordinates and dimensions of the view.
+ * Measures the size of the RecyclerView's outer container.
+ * Uses a self-relative measureLayout call to get width/height synchronously.
+ *
  * @param view - The React Native View component to measure
- * @returns An object containing x, y, width, and height measurements
+ * @returns An object containing width and height
  */
-export function measureParentSize(view: View): Layout {
-  return measureLayout(view, undefined);
+export function measureParentSize(view: View): Size {
+  const layout = measureLayout(view, undefined);
+  return { width: layout.width, height: layout.height };
 }
 
 /**

src/recyclerview/utils/measureLayout.web.ts

@@ -5,6 +5,11 @@ interface Layout {
   height: number;
 }
 
+interface Size {
+  width: number;
+  height: number;
+}
+
 /**
  * Gets scroll offsets from up to 3 parent elements
  */
@@ -43,12 +48,10 @@ export function roundOffPixel(value: number): number {
 }
 
 /**
- * Measures the layout of parent of RecyclerView
+ * Measures the size of the RecyclerView's outer container.
  */
-export function measureParentSize(view: Element): Layout {
+export function measureParentSize(view: Element): Size {
   return {
-    x: 0,
-    y: 0,
     width: view.clientWidth,
     height: view.clientHeight,
   };