From d2480b9f7d5088e91cef7078610833ee8ce0c7e4 Mon Sep 17 00:00:00 2001
From: Cheng-Hsuan Tsai <webcat@google.com>
Date: Thu, 23 Jul 2026 03:46:41 +0000
Subject: [PATCH] fix(aria/grid): account for disabled cell widgets and
 in-place disablement in roving tabindex

---
 src/aria/grid/grid.spec.ts                    | 90 +++++++++++++++++++
 src/aria/private/behaviors/grid/grid-focus.ts |  3 +-
 src/aria/private/grid/cell.ts                 |  4 +-
 3 files changed, 95 insertions(+), 2 deletions(-)

diff --git a/src/aria/grid/grid.spec.ts b/src/aria/grid/grid.spec.ts
index 3e799a4670eb..03fb5170b582 100644
--- a/src/aria/grid/grid.spec.ts
+++ b/src/aria/grid/grid.spec.ts
@@ -1059,6 +1059,96 @@ describe('Grid directives', () => {
         expect(widgetDirective.isActivated()).toBeFalse();
       });
     });
+
+    describe('disabled element roving tabindex calculation', () => {
+      it('should not choose disabled element as active cell when softDisabled is false upon cell deletion', async () => {
+        const gridData: RowConfig[] = [
+          {
+            cells: [{id: 'c0-0'}, {id: 'c0-1', disabled: true}, {id: 'c0-2'}],
+          },
+        ];
+        await setupGrid({
+          gridData,
+          softDisabled: false,
+          focusMode: 'roving',
+        });
+        gridInstance._pattern.setDefaultStateEffect();
+        await fixture.whenStable();
+
+        expect(getActiveCellId()).toBe('c0-0');
+
+        // Delete c0-0 so c0-1 (disabled) is now at index 0
+        fixture.componentInstance.gridData.set([
+          {
+            cells: [{id: 'c0-1', disabled: true}, {id: 'c0-2'}],
+          },
+        ]);
+        await fixture.whenStable();
+        await fixture.whenStable();
+
+        expect(getActiveCellId()).toBe('c0-2');
+      });
+
+      it('should not choose cell with disabled widget as active cell when softDisabled is false upon cell deletion', async () => {
+        const gridData: RowConfig[] = [
+          {
+            cells: [
+              {id: 'c0-0'},
+              {id: 'c0-1', widgets: [{id: 'w0-1', disabled: true}]},
+              {id: 'c0-2'},
+            ],
+          },
+        ];
+        await setupGrid({
+          gridData,
+          softDisabled: false,
+          focusMode: 'roving',
+        });
+        gridInstance._pattern.setDefaultStateEffect();
+        await fixture.whenStable();
+
+        expect(getActiveCellId()).toBe('c0-0');
+
+        // Delete c0-0 so c0-1 (with disabled widget) is now at index 0
+        fixture.componentInstance.gridData.set([
+          {
+            cells: [{id: 'c0-1', widgets: [{id: 'w0-1', disabled: true}]}, {id: 'c0-2'}],
+          },
+        ]);
+        await fixture.whenStable();
+        await fixture.whenStable();
+
+        expect(getActiveCellId()).toBe('c0-2');
+      });
+
+      it('should recalculate active cell when active cell dynamically becomes disabled and softDisabled is false', async () => {
+        const gridData: RowConfig[] = [
+          {
+            cells: [{id: 'c0-0'}, {id: 'c0-1'}, {id: 'c0-2'}],
+          },
+        ];
+        await setupGrid({
+          gridData,
+          softDisabled: false,
+          focusMode: 'roving',
+        });
+        gridInstance._pattern.setDefaultStateEffect();
+        await fixture.whenStable();
+
+        expect(getActiveCellId()).toBe('c0-0');
+
+        // Dynamically disable c0-0 in-place
+        fixture.componentInstance.gridData.set([
+          {
+            cells: [{id: 'c0-0', disabled: true}, {id: 'c0-1'}, {id: 'c0-2'}],
+          },
+        ]);
+        await fixture.whenStable();
+        await fixture.whenStable();
+
+        expect(getActiveCellId()).toBe('c0-1');
+      });
+    });
   });
 
   describe('structural validations', () => {
diff --git a/src/aria/private/behaviors/grid/grid-focus.ts b/src/aria/private/behaviors/grid/grid-focus.ts
index 31f0502e80f7..f6b8a69dbf4c 100644
--- a/src/aria/private/behaviors/grid/grid-focus.ts
+++ b/src/aria/private/behaviors/grid/grid-focus.ts
@@ -73,7 +73,8 @@ export class GridFocus<T extends GridFocusCell> {
 
     const activeCellNotValid = activeCellCoords === undefined;
     const activeCellMismatch = activeCell !== activeCoordsCell;
-    return activeCellNotValid || activeCellMismatch;
+    const activeCellNotFocusable = !this.isFocusable(activeCell!);
+    return activeCellNotValid || activeCellMismatch || activeCellNotFocusable;
   });
 
   /** The id of the current active cell, for ARIA activedescendant. */
diff --git a/src/aria/private/grid/cell.ts b/src/aria/private/grid/cell.ts
index 121295985649..de913f595da0 100644
--- a/src/aria/private/grid/cell.ts
+++ b/src/aria/private/grid/cell.ts
@@ -56,7 +56,9 @@ export class GridCellPattern implements GridCell {
   readonly selectable: SignalLike<boolean> = () => this.inputs.selectable();
 
   /** Whether a cell is disabled. */
-  readonly disabled: SignalLike<boolean> = () => this.inputs.disabled();
+  readonly disabled: SignalLike<boolean> = computed(
+    () => this.inputs.disabled() || (this.inputs.widget()?.inputs.disabled() ?? false),
+  );
 
   /** The number of rows the cell should span. */
   readonly rowSpan: SignalLike<number> = () => this.inputs.rowSpan();