6 const activeElement = document.activeElement;
7 return activeElement instanceof HTMLElement && rootElement.contains(activeElement) ? activeElement : null;
8 }
9+// T3 Code: the scroller's top padding is chrome its rows scroll under, so it is not viewport.
10+function readScrollTopInset(scrollElement) {
11+ return Number.parseFloat(getComputedStyle(scrollElement).paddingTop) || 0;
12+}
13 function readMeasuredViewportHeight(scrollElement, fallbackViewportHeight) {
14 if (scrollElement == null) return fallbackViewportHeight;
15+ const inset = readScrollTopInset(scrollElement);
16 const rectHeight = scrollElement.getBoundingClientRect().height;
17- if (rectHeight > 0) return rectHeight;
18- return scrollElement.clientHeight > 0 ? scrollElement.clientHeight : fallbackViewportHeight;
19+ if (rectHeight > 0) return Math.max(1, rectHeight - inset);
20+ return scrollElement.clientHeight > 0 ? Math.max(1, scrollElement.clientHeight - inset) : fallbackViewportHeight;
21 }
22 function getCachedViewportHeight(cachedViewportHeight, fallbackViewportHeight) {
23 return cachedViewportHeight != null && cachedViewportHeight > 0 ? cachedViewportHeight : fallbackViewportHeight;
25 function getResizeObserverViewportHeight(entry) {
26 const borderBoxSize = entry.borderBoxSize;
27 const firstBorderBoxSize = Array.isArray(borderBoxSize) ? borderBoxSize[0] : borderBoxSize;
28- if (firstBorderBoxSize != null && Number.isFinite(firstBorderBoxSize.blockSize) && firstBorderBoxSize.blockSize > 0) return firstBorderBoxSize.blockSize;
29+ if (firstBorderBoxSize != null && Number.isFinite(firstBorderBoxSize.blockSize) && firstBorderBoxSize.blockSize > 0) return Math.max(1, firstBorderBoxSize.blockSize - readScrollTopInset(entry.target));
30 return entry.contentRect.height > 0 ? entry.contentRect.height : null;
31 }
32 function scrollFocusedRowIntoView(scrollElement, focusedIndex, itemHeight, viewportHeight, topInset = 0) {