From b6a8f385afef31b55a4a4c176280b809febbf8cc Mon Sep 17 00:00:00 2001
From: Lukas Harbarth <lukas.harbarth@sap.com>
Date: Mon, 29 Sep 2025 09:41:47 +0200
Subject: [PATCH 1/2] fix(ObjectPage): support height change of pinned header

---
 .../main/src/internal/useObserveHeights.ts    | 24 ++++++++-----------
 1 file changed, 10 insertions(+), 14 deletions(-)

diff --git a/packages/main/src/internal/useObserveHeights.ts b/packages/main/src/internal/useObserveHeights.ts
index b6e1f319099..c5aec3e81aa 100644
--- a/packages/main/src/internal/useObserveHeights.ts
+++ b/packages/main/src/internal/useObserveHeights.ts
@@ -66,11 +66,10 @@ export const useObserveHeights = (
 
   // top header
   useEffect(() => {
-    const headerContentResizeObserver = new ResizeObserver(([header]) => {
-      // Firefox implements `borderBoxSize` as a single content rect, rather than an array
-      const borderBoxSize = Array.isArray(header.borderBoxSize) ? header.borderBoxSize[0] : header.borderBoxSize;
-      // Safari doesn't implement `borderBoxSize`
-      setTopHeaderHeight(borderBoxSize?.blockSize ?? header.target.getBoundingClientRect().height);
+    const headerContentResizeObserver = new ResizeObserver(([entry]) => {
+      const { blockSize } = entry.borderBoxSize[0];
+      console.log('a');
+      setTopHeaderHeight(blockSize);
     });
     if (topHeaderRef?.current) {
       headerContentResizeObserver.observe(topHeaderRef.current);
@@ -82,14 +81,11 @@ export const useObserveHeights = (
 
   // header content
   useEffect(() => {
-    const headerContentResizeObserver = new ResizeObserver(([headerContent]) => {
-      if (isIntersecting) {
-        // Firefox implements `borderBoxSize` as a single content rect, rather than an array
-        const borderBoxSize = Array.isArray(headerContent.borderBoxSize)
-          ? headerContent.borderBoxSize[0]
-          : headerContent.borderBoxSize;
-        // Safari doesn't implement `borderBoxSize`
-        setHeaderContentHeight(borderBoxSize?.blockSize ?? headerContent.target.getBoundingClientRect().height);
+    const headerContentResizeObserver = new ResizeObserver(([entry]) => {
+      if (isIntersecting || fixedHeader) {
+        const { blockSize } = entry.borderBoxSize[0];
+        console.log('b');
+        setHeaderContentHeight(blockSize);
       }
     });
 
@@ -99,7 +95,7 @@ export const useObserveHeights = (
     return () => {
       headerContentResizeObserver.disconnect();
     };
-  }, [isIntersecting]);
+  }, [isIntersecting, fixedHeader]);
   const totalHeaderHeight = noHeader ? 0 : topHeaderHeight + headerContentHeight;
 
   return { topHeaderHeight, headerContentHeight, totalHeaderHeight, headerCollapsed };

From 03e87688f2b608c7e559cf8e5dd96400036dc4c5 Mon Sep 17 00:00:00 2001
From: Lukas Harbarth <lukas.harbarth@sap.com>
Date: Mon, 29 Sep 2025 09:42:27 +0200
Subject: [PATCH 2/2] cleanup

---
 packages/main/src/internal/useObserveHeights.ts | 2 --
 1 file changed, 2 deletions(-)

diff --git a/packages/main/src/internal/useObserveHeights.ts b/packages/main/src/internal/useObserveHeights.ts
index c5aec3e81aa..b5a9ffdd1c9 100644
--- a/packages/main/src/internal/useObserveHeights.ts
+++ b/packages/main/src/internal/useObserveHeights.ts
@@ -68,7 +68,6 @@ export const useObserveHeights = (
   useEffect(() => {
     const headerContentResizeObserver = new ResizeObserver(([entry]) => {
       const { blockSize } = entry.borderBoxSize[0];
-      console.log('a');
       setTopHeaderHeight(blockSize);
     });
     if (topHeaderRef?.current) {
@@ -84,7 +83,6 @@ export const useObserveHeights = (
     const headerContentResizeObserver = new ResizeObserver(([entry]) => {
       if (isIntersecting || fixedHeader) {
         const { blockSize } = entry.borderBoxSize[0];
-        console.log('b');
         setHeaderContentHeight(blockSize);
       }
     });