feat(core/dropdown): support roving tabindex keyboard navigation

.changeset/dropdown-roving-tabindex.md

@@ -0,0 +1,5 @@
+---
+'@siemens/ix': minor
+---
+
+Added a `navigationMode` property to `ix-dropdown` (and passed through by `ix-dropdown-button`) that selects the keyboard navigation strategy. The new `roving-tabindex` mode moves real DOM focus between items via a roving `tabindex` (`0` for the active item, `-1` for the rest), so items are actually focused and no `aria-activedescendant` is required. Besides the built-in item components, arbitrary focusable elements (e.g. a native `<button>`) can opt into this navigation by adding the `data-ix-roving-item` attribute; such native elements keep their own activation (<kbd>Enter</kbd> / <kbd>Space</kbd> fire a real click). In this mode pressing <kbd>Tab</kbd> / <kbd>Shift</kbd>+<kbd>Tab</kbd> closes the dropdown and moves focus to the next/previous element in the active focus scope, including an owning `ix-popover`. Dropdowns and popovers now share nested-overlay ownership so item-triggered popovers remain open; <kbd>Escape</kbd> closes a complete dropdown hierarchy before its owning popover, while nested popovers close one at a time. The default `active-descendant` mode keeps the existing behavior where DOM focus stays on the trigger and a visual focus indicator moves between items.

packages/angular-standalone-test-app/src/app/app.routes.ts

@@ -184,6 +184,10 @@ export const routePaths: IxPreviewRoutes = {
     import('../preview-examples/dropdown-icon').then((m) => m.default),
   'preview/dropdown-quick-actions': () =>
     import('../preview-examples/dropdown-quick-actions').then((m) => m.default),
+  'preview/dropdown-roving-tabindex': () =>
+    import('../preview-examples/dropdown-roving-tabindex').then(
+      (m) => m.default
+    ),
   'preview/dropdown-submenu': () =>
     import('../preview-examples/dropdown-submenu').then((m) => m.default),
   'preview/echarts': () =>

packages/angular-standalone-test-app/src/preview-examples/dropdown-roving-tabindex.ts

@@ -0,0 +1,42 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Siemens AG
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import { Component } from '@angular/core';
+import {
+  IxButton,
+  IxDropdown,
+  IxDropdownHeader,
+  IxDropdownItem,
+  IxDivider,
+  IxDropdownTriggerDirective,
+} from '@siemens/ix-angular/standalone';
+
+@Component({
+  selector: 'app-example',
+  imports: [
+    IxButton,
+    IxDropdown,
+    IxDropdownHeader,
+    IxDropdownItem,
+    IxDivider,
+    IxDropdownTriggerDirective,
+  ],
+  template: `
+    <ix-button #trigger>Open</ix-button>
+    <ix-dropdown [ixDropdownTrigger]="trigger" navigationMode="roving-tabindex">
+      <ix-dropdown-header label="Category"></ix-dropdown-header>
+      <ix-dropdown-item label="Item 2"></ix-dropdown-item>
+      <ix-dropdown-item label="Item 3"></ix-dropdown-item>
+      <ix-dropdown-item label="Item 4"></ix-dropdown-item>
+      <ix-divider></ix-divider>
+      <ix-dropdown-item label="Item 5"></ix-dropdown-item>
+    </ix-dropdown>
+  `,
+})
+export default class DropdownRovingTabindex {}

packages/angular-test-app/src/app/app-routing.module.ts

@@ -83,6 +83,7 @@ import DropdownButton from '../preview-examples/dropdown-button';
 import DropdownButtonIcon from '../preview-examples/dropdown-button-icon';
 import DropdownIcon from '../preview-examples/dropdown-icon';
 import DropdownQuickActions from '../preview-examples/dropdown-quick-actions';
+import DropdownRovingTabindex from '../preview-examples/dropdown-roving-tabindex';
 import DropdownSubmenu from '../preview-examples/dropdown-submenu';
 import Echarts from '../preview-examples/echarts';
 import EchartsBarHorizontalStacked from '../preview-examples/echarts-bar-horizontal-stacked';
@@ -570,6 +571,10 @@ const routes: Routes = [
         path: 'dropdown-quick-actions',
         component: DropdownQuickActions,
       },
+      {
+        path: 'dropdown-roving-tabindex',
+        component: DropdownRovingTabindex,
+      },
       {
         path: 'dropdown-submenu',
         component: DropdownSubmenu,

packages/angular-test-app/src/app/app.module.ts

@@ -92,6 +92,7 @@ import DropdownButton from '../preview-examples/dropdown-button';
 import DropdownButtonIcon from '../preview-examples/dropdown-button-icon';
 import DropdownIcon from '../preview-examples/dropdown-icon';
 import DropdownQuickActions from '../preview-examples/dropdown-quick-actions';
+import DropdownRovingTabindex from '../preview-examples/dropdown-roving-tabindex';
 import DropdownSubmenu from '../preview-examples/dropdown-submenu';
 import Echarts from '../preview-examples/echarts';
 import EchartsBarHorizontalStacked from '../preview-examples/echarts-bar-horizontal-stacked';
@@ -347,6 +348,7 @@ import WorkflowVertical from '../preview-examples/workflow-vertical';
     DropdownButton,
     DropdownIcon,
     DropdownQuickActions,
+    DropdownRovingTabindex,
     DropdownSubmenu,
     Dropdown,
     Echarts,

packages/angular-test-app/src/preview-examples/dropdown-roving-tabindex.ts

@@ -0,0 +1,27 @@
+/*
+ * SPDX-FileCopyrightText: 2026 Siemens AG
+ *
+ * SPDX-License-Identifier: MIT
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import { Component } from '@angular/core';
+
+@Component({
+  standalone: false,
+  selector: 'app-example',
+  template: `
+    <ix-button #trigger>Open</ix-button>
+    <ix-dropdown [ixDropdownTrigger]="trigger" navigationMode="roving-tabindex">
+      <ix-dropdown-header label="Category"></ix-dropdown-header>
+      <ix-dropdown-item label="Item 2"></ix-dropdown-item>
+      <ix-dropdown-item label="Item 3"></ix-dropdown-item>
+      <ix-dropdown-item label="Item 4"></ix-dropdown-item>
+      <ix-divider></ix-divider>
+      <ix-dropdown-item label="Item 5"></ix-dropdown-item>
+    </ix-dropdown>
+  `,
+})
+export default class DropdownRovingTabindex {}

packages/angular/src/components.ts

@@ -849,15 +849,15 @@ export declare interface IxDivider extends Components.IxDivider {}
 
 
 @ProxyCmp({
-  inputs: ['anchor', 'closeBehavior', 'disableFocusHandling', 'disableFocusTrap', 'enableTopLayer', 'focusCheckedItem', 'header', 'placement', 'positioningStrategy', 'show', 'suppressAutomaticPlacement', 'suppressTriggerVisibilityCheck', 'trigger'],
+  inputs: ['anchor', 'closeBehavior', 'disableFocusHandling', 'disableFocusTrap', 'enableTopLayer', 'focusCheckedItem', 'header', 'navigationMode', 'placement', 'positioningStrategy', 'show', 'suppressAutomaticPlacement', 'suppressTriggerVisibilityCheck', 'trigger'],
   methods: ['updatePosition']
 })
 @Component({
   selector: 'ix-dropdown',
   changeDetection: ChangeDetectionStrategy.OnPush,
   template: '<ng-content></ng-content>',
   // eslint-disable-next-line @angular-eslint/no-inputs-metadata-property
-  inputs: ['anchor', 'closeBehavior', 'disableFocusHandling', 'disableFocusTrap', 'enableTopLayer', 'focusCheckedItem', 'header', 'placement', 'positioningStrategy', 'show', 'suppressAutomaticPlacement', 'suppressTriggerVisibilityCheck', 'trigger'],
+  inputs: ['anchor', 'closeBehavior', 'disableFocusHandling', 'disableFocusTrap', 'enableTopLayer', 'focusCheckedItem', 'header', 'navigationMode', 'placement', 'positioningStrategy', 'show', 'suppressAutomaticPlacement', 'suppressTriggerVisibilityCheck', 'trigger'],
   outputs: ['showChange', 'showChanged'],
   standalone: false
 })
@@ -885,14 +885,14 @@ export declare interface IxDropdown extends Components.IxDropdown {
 
 
 @ProxyCmp({
-  inputs: ['ariaLabelDropdownButton', 'closeBehavior', 'disabled', 'enableTopLayer', 'focusCheckedItem', 'icon', 'label', 'placement', 'variant']
+  inputs: ['ariaLabelDropdownButton', 'closeBehavior', 'disabled', 'enableTopLayer', 'focusCheckedItem', 'icon', 'label', 'navigationMode', 'placement', 'variant']
 })
 @Component({
   selector: 'ix-dropdown-button',
   changeDetection: ChangeDetectionStrategy.OnPush,
   template: '<ng-content></ng-content>',
   // eslint-disable-next-line @angular-eslint/no-inputs-metadata-property
-  inputs: ['ariaLabelDropdownButton', 'closeBehavior', 'disabled', 'enableTopLayer', 'focusCheckedItem', 'icon', 'label', 'placement', 'variant'],
+  inputs: ['ariaLabelDropdownButton', 'closeBehavior', 'disabled', 'enableTopLayer', 'focusCheckedItem', 'icon', 'label', 'navigationMode', 'placement', 'variant'],
   outputs: ['showChange', 'showChanged'],
   standalone: false
 })

packages/angular/standalone/src/components.ts

@@ -954,15 +954,15 @@ export declare interface IxDivider extends Components.IxDivider {}
 
 @ProxyCmp({
   defineCustomElementFn: defineIxDropdown,
-  inputs: ['anchor', 'closeBehavior', 'disableFocusHandling', 'disableFocusTrap', 'enableTopLayer', 'focusCheckedItem', 'header', 'placement', 'positioningStrategy', 'show', 'suppressAutomaticPlacement', 'suppressTriggerVisibilityCheck', 'trigger'],
+  inputs: ['anchor', 'closeBehavior', 'disableFocusHandling', 'disableFocusTrap', 'enableTopLayer', 'focusCheckedItem', 'header', 'navigationMode', 'placement', 'positioningStrategy', 'show', 'suppressAutomaticPlacement', 'suppressTriggerVisibilityCheck', 'trigger'],
   methods: ['updatePosition']
 })
 @Component({
   selector: 'ix-dropdown',
   changeDetection: ChangeDetectionStrategy.OnPush,
   template: '<ng-content></ng-content>',
   // eslint-disable-next-line @angular-eslint/no-inputs-metadata-property
-  inputs: ['anchor', 'closeBehavior', 'disableFocusHandling', 'disableFocusTrap', 'enableTopLayer', 'focusCheckedItem', 'header', 'placement', 'positioningStrategy', 'show', 'suppressAutomaticPlacement', 'suppressTriggerVisibilityCheck', 'trigger'],
+  inputs: ['anchor', 'closeBehavior', 'disableFocusHandling', 'disableFocusTrap', 'enableTopLayer', 'focusCheckedItem', 'header', 'navigationMode', 'placement', 'positioningStrategy', 'show', 'suppressAutomaticPlacement', 'suppressTriggerVisibilityCheck', 'trigger'],
   outputs: ['showChange', 'showChanged'],
 })
 export class IxDropdown {
@@ -990,14 +990,14 @@ export declare interface IxDropdown extends Components.IxDropdown {
 
 @ProxyCmp({
   defineCustomElementFn: defineIxDropdownButton,
-  inputs: ['ariaLabelDropdownButton', 'closeBehavior', 'disabled', 'enableTopLayer', 'focusCheckedItem', 'icon', 'label', 'placement', 'variant']
+  inputs: ['ariaLabelDropdownButton', 'closeBehavior', 'disabled', 'enableTopLayer', 'focusCheckedItem', 'icon', 'label', 'navigationMode', 'placement', 'variant']
 })
 @Component({
   selector: 'ix-dropdown-button',
   changeDetection: ChangeDetectionStrategy.OnPush,
   template: '<ng-content></ng-content>',
   // eslint-disable-next-line @angular-eslint/no-inputs-metadata-property
-  inputs: ['ariaLabelDropdownButton', 'closeBehavior', 'disabled', 'enableTopLayer', 'focusCheckedItem', 'icon', 'label', 'placement', 'variant'],
+  inputs: ['ariaLabelDropdownButton', 'closeBehavior', 'disabled', 'enableTopLayer', 'focusCheckedItem', 'icon', 'label', 'navigationMode', 'placement', 'variant'],
   outputs: ['showChange', 'showChanged'],
 })
 export class IxDropdownButton {

packages/core/src/components.d.ts

@@ -1555,6 +1555,12 @@ export namespace Components {
           * @default ['Enter', ' ']
          */
         "keyboardItemTriggerKeys": string[];
+        /**
+          * Controls how keyboard navigation moves focus between dropdown items.  - `active-descendant`: DOM focus stays on the trigger/anchor element while a   visual focus indicator moves between the items. Consumers can expose the   active item through `aria-activedescendant`. - `roving-tabindex`: real DOM focus is moved to each item using a roving   `tabindex` (`0` for the active item, `-1` for the others). No   `aria-activedescendant` is required because the focused item is announced   directly. Besides the built-in item components, arbitrary focusable   elements (e.g. a native `<button>`) can opt into this navigation by adding   the `data-ix-roving-item` attribute; such native elements keep their own   activation (<kbd>Enter</kbd> / <kbd>Space</kbd> fire a real click).
+          * @since 5.2.0
+          * @default 'active-descendant'
+         */
+        "navigationMode": 'active-descendant' | 'roving-tabindex';
         /**
           * Move dropdown along main axis of alignment
          */
@@ -1644,6 +1650,12 @@ export namespace Components {
           * Set label
          */
         "label"?: string | null;
+        /**
+          * Controls how keyboard navigation moves focus between dropdown items.  - `active-descendant`: DOM focus stays on the dropdown button while a visual   focus indicator moves between the items, exposed via `aria-activedescendant`. - `roving-tabindex`: real DOM focus is moved to each item using a roving   `tabindex` (`0` for the active item, `-1` for the others). No   `aria-activedescendant` is used because the focused item is announced   directly.
+          * @since 5.2.0
+          * @default 'active-descendant'
+         */
+        "navigationMode": 'active-descendant' | 'roving-tabindex';
         /**
           * Placement of the dropdown
          */
@@ -8171,6 +8183,12 @@ declare namespace LocalJSX {
           * @default ['Enter', ' ']
          */
         "keyboardItemTriggerKeys"?: string[];
+        /**
+          * Controls how keyboard navigation moves focus between dropdown items.  - `active-descendant`: DOM focus stays on the trigger/anchor element while a   visual focus indicator moves between the items. Consumers can expose the   active item through `aria-activedescendant`. - `roving-tabindex`: real DOM focus is moved to each item using a roving   `tabindex` (`0` for the active item, `-1` for the others). No   `aria-activedescendant` is required because the focused item is announced   directly. Besides the built-in item components, arbitrary focusable   elements (e.g. a native `<button>`) can opt into this navigation by adding   the `data-ix-roving-item` attribute; such native elements keep their own   activation (<kbd>Enter</kbd> / <kbd>Space</kbd> fire a real click).
+          * @since 5.2.0
+          * @default 'active-descendant'
+         */
+        "navigationMode"?: 'active-descendant' | 'roving-tabindex';
         /**
           * Move dropdown along main axis of alignment
          */
@@ -8269,6 +8287,12 @@ declare namespace LocalJSX {
           * Set label
          */
         "label"?: string | null;
+        /**
+          * Controls how keyboard navigation moves focus between dropdown items.  - `active-descendant`: DOM focus stays on the dropdown button while a visual   focus indicator moves between the items, exposed via `aria-activedescendant`. - `roving-tabindex`: real DOM focus is moved to each item using a roving   `tabindex` (`0` for the active item, `-1` for the others). No   `aria-activedescendant` is used because the focused item is announced   directly.
+          * @since 5.2.0
+          * @default 'active-descendant'
+         */
+        "navigationMode"?: 'active-descendant' | 'roving-tabindex';
         /**
           * Fire event before visibility of dropdown has changed, preventing event will cancel showing dropdown
          */
@@ -11879,6 +11903,7 @@ declare namespace LocalJSX {
         "disableFocusTrap": boolean;
         "enableTopLayer": boolean;
         "focusCheckedItem": boolean;
+        "navigationMode": 'active-descendant' | 'roving-tabindex';
         "discoverAllSubmenus": boolean;
         "ignoreRelatedSubmenu": boolean;
         "suppressOverflowBehavior": boolean;
@@ -11893,6 +11918,7 @@ declare namespace LocalJSX {
         "placement": AlignedPlacement;
         "ariaLabelDropdownButton": string;
         "focusCheckedItem": boolean;
+        "navigationMode": 'active-descendant' | 'roving-tabindex';
         "enableTopLayer": boolean;
         "suppressAriaActiveDescendant": boolean;
     }

packages/core/src/components/dropdown-button/dropdown-button.ct.ts

@@ -170,3 +170,121 @@ regressionTest(
     await expect(dropdown).not.toBeVisible();
   }
 );
+
+regressionTest(
+  'roving-tabindex navigation moves DOM focus without aria-activedescendant',
+  async ({ page, mount, makeAxeBuilder }) => {
+    await mount(`
+    <ix-dropdown-button label="Open" navigation-mode="roving-tabindex">
+      <ix-dropdown-item id="rov-1" label="Test1"></ix-dropdown-item>
+      <ix-dropdown-item id="rov-2" label="Test2"></ix-dropdown-item>
+      <ix-dropdown-item id="rov-3" label="Test3"></ix-dropdown-item>
+    </ix-dropdown-button>
+  `);
+    const button = page.locator('ix-dropdown-button');
+    const item1 = page.locator('#rov-1');
+    const item2 = page.locator('#rov-2');
+
+    const $onClickItem2 = item2.evaluateHandle(
+      (el) =>
+        new Promise<void>((resolve) => {
+          el.addEventListener('click', () => resolve());
+        })
+    );
+
+    await expect(button).toHaveClass(/hydrated/);
+
+    await page.keyboard.press('Tab');
+    await page.keyboard.press('ArrowDown');
+
+    const dropdown = button.locator('ix-dropdown');
+    await expect(dropdown).toBeVisible();
+
+    await expect(item1).toBeFocused();
+    await expect(item1).toHaveAttribute('tabindex', '0');
+    await expect(button).not.toHaveAttribute('aria-activedescendant');
+
+    const accessibilityScanResults = await makeAxeBuilder()
+      .include('ix-dropdown-item')
+      .analyze();
+    expect(accessibilityScanResults.violations).toEqual([]);
+
+    await page.keyboard.press('ArrowDown');
+    await expect(item2).toBeFocused();
+    await expect(item2).toHaveAttribute('tabindex', '0');
+    await expect(item1).toHaveAttribute('tabindex', '-1');
+
+    await page.keyboard.press('Enter');
+
+    await $onClickItem2;
+    await expect(dropdown).not.toBeVisible();
+  }
+);
+
+regressionTest(
+  'roving-tabindex closes on Tab and moves focus past the dropdown button',
+  async ({ page, mount, makeAxeBuilder }) => {
+    await mount(`
+      <button id="before">Before</button>
+      <ix-dropdown-button label="Open" navigation-mode="roving-tabindex">
+        <ix-dropdown-item id="tab-1" label="Test1"></ix-dropdown-item>
+        <ix-dropdown-item id="tab-2" label="Test2"></ix-dropdown-item>
+      </ix-dropdown-button>
+      <button id="after">After</button>
+    `);
+    const button = page.locator('ix-dropdown-button');
+    const dropdown = button.locator('ix-dropdown');
+    const item1 = page.locator('#tab-1');
+    const after = page.locator('#after');
+
+    await expect(button).toHaveClass(/hydrated/);
+    await button.focus();
+    await page.keyboard.press('ArrowDown');
+    await expect(item1).toBeFocused();
+
+    const accessibilityScanResults = await makeAxeBuilder()
+      .include('ix-dropdown-item')
+      .analyze();
+    expect(accessibilityScanResults.violations).toEqual([]);
+
+    await page.keyboard.press('Tab');
+
+    await expect(dropdown).not.toBeVisible();
+    await expect(after).toBeFocused();
+  }
+);
+
+regressionTest(
+  'updates the open dropdown when navigation mode changes',
+  async ({ page, mount }) => {
+    await mount(`
+      <ix-dropdown-button label="Open">
+        <ix-dropdown-item id="dynamic-1" label="Test1"></ix-dropdown-item>
+        <ix-dropdown-item id="dynamic-2" label="Test2"></ix-dropdown-item>
+      </ix-dropdown-button>
+    `);
+    const button = page.locator('ix-dropdown-button');
+    const item1 = page.locator('#dynamic-1');
+
+    await expect(button).toHaveClass(/hydrated/);
+    await button.focus();
+    await page.keyboard.press('ArrowDown');
+    await expect(button).toHaveAttribute('aria-activedescendant', 'dynamic-1');
+
+    await button.evaluate(
+      (element: HTMLIxDropdownButtonElement) =>
+        (element.navigationMode = 'roving-tabindex')
+    );
+
+    await expect(item1).toBeFocused();
+    await expect(button).not.toHaveAttribute('aria-activedescendant');
+
+    await button.evaluate(
+      (element: HTMLIxDropdownButtonElement) =>
+        (element.navigationMode = 'active-descendant')
+    );
+
+    await expect(button).toBeFocused();
+    await expect(button).toHaveAttribute('aria-activedescendant', 'dynamic-1');
+  }
+);