fixup! ♿️(frontend) fix sidebar resize handle for screen readers

CHANGELOG.md

@@ -9,7 +9,7 @@ and this project adheres to
 ### Changed
 
 - 💄(frontend) improve comments highlights #1961
-  ♿️(frontend) fix sidebar resize handle for screen readers #2122
+- ♿️(frontend) fix sidebar resize handle for screen readers #2122
 
 ## [v4.8.3] - 2026-03-23
 

src/frontend/apps/impress/src/features/left-panel/components/ResizableLeftPanel.tsx

@@ -16,6 +16,23 @@ const pxToPercent = (px: number) => {
   return (px / window.innerWidth) * 100;
 };
 
+const RESIZE_HANDLE_ID = 'left-panel-resize-handle';
+
+const getSidebarWidthLabel = (
+  current: number,
+  min: number,
+  max: number,
+): 'narrow' | 'medium' | 'wide' => {
+  const ratio = (current - min) / (max - min);
+  if (ratio < 1 / 3) {
+    return 'narrow';
+  }
+  if (ratio < 2 / 3) {
+    return 'medium';
+  }
+  return 'wide';
+};
+
 type ResizableLeftPanelProps = {
   leftPanel: React.ReactNode;
   children: React.ReactNode;
@@ -23,8 +40,6 @@ type ResizableLeftPanelProps = {
   maxPanelSizePx?: number;
 };
 
-const RESIZE_HANDLE_ID = 'left-panel-resize-handle';
-
 export const ResizableLeftPanel = ({
   leftPanel,
   children,
@@ -102,47 +117,21 @@ export const ResizableLeftPanel = ({
 
   /**
    * Workaround: NVDA does not enter focus mode for role="separator"
+   * (https://github.com/nvaccess/nvda/issues/11403), so arrow keys are
    * intercepted by browse-mode navigation and never reach the handle.
    * Changing the role to "slider" makes NVDA reliably switch to focus
    * mode, restoring progressive keyboard resize with arrow keys.
+   *
+   * Note: PanelResizeHandle does not expose a ref (no RefAttributes in its
+   * type definition), so we use id + getElementById as the only viable option.
+   * Only role needs to be overridden here; aria-* props are passed directly.
    */
   useEffect(() => {
     if (!isPanelOpen) {
       return;
     }
-    const handle = document.getElementById(RESIZE_HANDLE_ID);
-    if (!handle) {
-      return;
-    }
-
-    handle.setAttribute('role', 'slider');
-    handle.setAttribute('aria-orientation', 'vertical');
-    handle.setAttribute('aria-label', t('Resize sidebar'));
-
-    const updateValueText = () => {
-      const value = handle.getAttribute('aria-valuenow');
-      if (value) {
-        const widthPx = Math.round(
-          (parseFloat(value) / 100) * window.innerWidth,
-        );
-        handle.setAttribute(
-          'aria-valuetext',
-          t('Sidebar width: {{widthPx}} pixels', { widthPx }),
-        );
-      }
-    };
-    updateValueText();
-
-    const observer = new MutationObserver(updateValueText);
-    observer.observe(handle, {
-      attributes: true,
-      attributeFilter: ['aria-valuenow'],
-    });
-
-    return () => {
-      observer.disconnect();
-    };
-  }, [isPanelOpen, t]);
+    document.getElementById(RESIZE_HANDLE_ID)?.setAttribute('role', 'slider');
+  }, [isPanelOpen]);
 
   const handleResize = (sizePercent: number) => {
     const widthPx = (sizePercent / 100) * window.innerWidth;
@@ -181,6 +170,20 @@ export const ResizableLeftPanel = ({
       {isPanelOpen && (
         <PanelResizeHandle
           id={RESIZE_HANDLE_ID}
+          aria-label={t('Resize sidebar')}
+          aria-orientation="vertical"
+          aria-valuemin={Math.round(minPanelSizePercent)}
+          aria-valuemax={Math.round(maxPanelSizePercent)}
+          aria-valuenow={Math.round(panelSizePercent)}
+          aria-valuetext={t(`Sidebar width: {{label}}`, {
+            label: t(
+              getSidebarWidthLabel(
+                panelSizePercent,
+                minPanelSizePercent,
+                maxPanelSizePercent,
+              ),
+            ),
+          })}
           style={{
             borderRightWidth: '1px',
             borderRightStyle: 'solid',