fix(cdk/listbox): make tabindex zoneless compatible

Author: mmalerba

src/cdk/a11y/key-manager/list-key-manager.ts

@@ -6,20 +6,20 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import {EffectRef, Injector, QueryList, Signal, effect, isSignal} from '@angular/core';
-import {Subject, Subscription} from 'rxjs';
 import {
-  UP_ARROW,
   DOWN_ARROW,
+  END,
+  HOME,
   LEFT_ARROW,
+  PAGE_DOWN,
+  PAGE_UP,
   RIGHT_ARROW,
   TAB,
+  UP_ARROW,
   hasModifierKey,
-  HOME,
-  END,
-  PAGE_UP,
-  PAGE_DOWN,
 } from '@angular/cdk/keycodes';
+import {EffectRef, Injector, QueryList, Signal, effect, isSignal, signal} from '@angular/core';
+import {Subject, Subscription} from 'rxjs';
 import {Typeahead} from './typeahead';
 
 /** This interface is for items that can be passed to a ListKeyManager. */
@@ -40,7 +40,7 @@ export type ListKeyManagerModifierKey = 'altKey' | 'ctrlKey' | 'metaKey' | 'shif
  */
 export class ListKeyManager<T extends ListKeyManagerOption> {
   private _activeItemIndex = -1;
-  private _activeItem: T | null = null;
+  private _activeItem = signal<T | null>(null);
   private _wrap = false;
   private _typeaheadSubscription = Subscription.EMPTY;
   private _itemChangesSubscription?: Subscription;
@@ -204,11 +204,11 @@ export class ListKeyManager<T extends ListKeyManagerOption> {
   setActiveItem(item: T): void;
 
   setActiveItem(item: any): void {
-    const previousActiveItem = this._activeItem;
+    const previousActiveItem = this._activeItem();
 
     this.updateActiveItem(item);
 
-    if (this._activeItem !== previousActiveItem) {
+    if (this._activeItem() !== previousActiveItem) {
       this.change.next(this._activeItemIndex);
     }
   }
@@ -317,7 +317,7 @@ export class ListKeyManager<T extends ListKeyManagerOption> {
 
   /** The active item. */
   get activeItem(): T | null {
-    return this._activeItem;
+    return this._activeItem();
   }
 
   /** Gets whether the user is currently typing into the manager using the typeahead feature. */
@@ -365,7 +365,7 @@ export class ListKeyManager<T extends ListKeyManagerOption> {
     const activeItem = itemArray[index];
 
     // Explicitly check for `null` and `undefined` because other falsy values are valid.
-    this._activeItem = activeItem == null ? null : activeItem;
+    this._activeItem.set(activeItem == null ? null : activeItem);
     this._activeItemIndex = index;
     this._typeahead?.setCurrentSelectedItemIndex(index);
   }
@@ -452,8 +452,9 @@ export class ListKeyManager<T extends ListKeyManagerOption> {
   /** Callback for when the items have changed. */
   private _itemsChanged(newItems: T[] | readonly T[]) {
     this._typeahead?.setItems(newItems);
-    if (this._activeItem) {
-      const newIndex = newItems.indexOf(this._activeItem);
+    const activeItem = this._activeItem();
+    if (activeItem) {
+      const newIndex = newItems.indexOf(activeItem);
 
       if (newIndex > -1 && newIndex !== this._activeItemIndex) {
         this._activeItemIndex = newIndex;

src/cdk/listbox/listbox.ts

@@ -42,6 +42,7 @@ import {
   OnDestroy,
   Output,
   QueryList,
+  signal,
 } from '@angular/core';
 import {ControlValueAccessor, NG_VALUE_ACCESSOR} from '@angular/forms';
 import {defer, fromEvent, merge, Observable, Subject} from 'rxjs';
@@ -120,24 +121,24 @@ export class CdkOption<T = unknown> implements ListKeyManagerOption, Highlightab
   /** Whether this option is disabled. */
   @Input({alias: 'cdkOptionDisabled', transform: booleanAttribute})
   get disabled(): boolean {
-    return this.listbox.disabled || this._disabled;
+    return this.listbox.disabled || this._disabled();
   }
   set disabled(value: boolean) {
-    this._disabled = value;
+    this._disabled.set(value);
   }
-  private _disabled: boolean = false;
+  private _disabled = signal(false);
 
   /** The tabindex of the option when it is enabled. */
   @Input('tabindex')
   get enabledTabIndex() {
-    return this._enabledTabIndex === undefined
+    return this._enabledTabIndex() === undefined
       ? this.listbox.enabledTabIndex
-      : this._enabledTabIndex;
+      : this._enabledTabIndex();
   }
   set enabledTabIndex(value) {
-    this._enabledTabIndex = value;
+    this._enabledTabIndex.set(value);
   }
-  private _enabledTabIndex?: number | null;
+  private _enabledTabIndex = signal<number | null | undefined>(undefined);
 
   /** The option's host element */
   readonly element: HTMLElement = inject(ElementRef).nativeElement;
@@ -269,12 +270,12 @@ export class CdkListbox<T = unknown> implements AfterContentInit, OnDestroy, Con
   /** The tabindex to use when the listbox is enabled. */
   @Input('tabindex')
   get enabledTabIndex() {
-    return this._enabledTabIndex === undefined ? 0 : this._enabledTabIndex;
+    return this._enabledTabIndex() === undefined ? 0 : this._enabledTabIndex();
   }
   set enabledTabIndex(value) {
-    this._enabledTabIndex = value;
+    this._enabledTabIndex.set(value);
   }
-  private _enabledTabIndex?: number | null;
+  private _enabledTabIndex = signal<number | null | undefined>(undefined);
 
   /** The value selected in the listbox, represented as an array of option values. */
   @Input('cdkListboxValue')
@@ -303,11 +304,23 @@ export class CdkListbox<T = unknown> implements AfterContentInit, OnDestroy, Con
 
   /** Whether the listbox is disabled. */
   @Input({alias: 'cdkListboxDisabled', transform: booleanAttribute})
-  disabled: boolean = false;
+  get disabled() {
+    return this._disabled();
+  }
+  set disabled(value: boolean) {
+    this._disabled.set(value);
+  }
+  private _disabled = signal(false);
 
   /** Whether the listbox will use active descendant or will move focus onto the options. */
   @Input({alias: 'cdkListboxUseActiveDescendant', transform: booleanAttribute})
-  useActiveDescendant: boolean = false;
+  get useActiveDescendant() {
+    return this._useActiveDescendant();
+  }
+  set useActiveDescendant(value: boolean) {
+    this._useActiveDescendant.set(value);
+  }
+  private _useActiveDescendant = signal(false);
 
   /** The orientation of the listbox. Only affects keyboard interaction, not visual layout. */
   @Input('cdkListboxOrientation')