refactor(aria/tree): passthrough property accessors directly from patterns

Author: adolgachev

src/aria/private/tree/tree.ts

@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import {computed, signal} from '@angular/core';
+import {computed, signal, Signal} from '@angular/core';
 import {SignalLike, WritableSignalLike} from '../behaviors/signal-like/signal-like';
 import {List, ListInputs, ListItem} from '../behaviors/list/list';
 import {ExpansionItem, ExpansionControl, ListExpansion} from '../behaviors/expansion/expansion';
@@ -74,13 +74,13 @@ export class TreeItemPattern<V> implements ListItem<V>, ExpansionItem {
   readonly selectable: SignalLike<boolean>;
 
   /** The level of the current item in a tree. */
-  readonly level: SignalLike<number> = computed(() => this.parent().level() + 1);
+  readonly level: Signal<number> = computed(() => this.parent().level() + 1);
 
   /** Whether this item is currently expanded. */
   readonly expanded = computed(() => this.expansion.isExpanded());
 
   /** Whether this item is visible. */
-  readonly visible: SignalLike<boolean> = computed(
+  readonly visible: Signal<boolean> = computed(
     () => this.parent().expanded() && this.parent().visible(),
   );
 
@@ -97,7 +97,7 @@ export class TreeItemPattern<V> implements ListItem<V>, ExpansionItem {
   readonly tabindex = computed(() => this.tree().listBehavior.getItemTabindex(this));
 
   /** Whether the item is selected. */
-  readonly selected: SignalLike<boolean | undefined> = computed(() => {
+  readonly selected = computed(() => {
     if (this.tree().nav()) {
       return undefined;
     }
@@ -108,7 +108,7 @@ export class TreeItemPattern<V> implements ListItem<V>, ExpansionItem {
   });
 
   /** The current type of this item. */
-  readonly current: SignalLike<string | undefined> = computed(() => {
+  readonly current = computed(() => {
     if (!this.tree().nav()) {
       return undefined;
     }

src/aria/tree/tree.ts

@@ -271,6 +271,9 @@ export class TreeItem<V> extends DeferredContentAware implements OnInit, OnDestr
   /** Search term for typeahead. */
   readonly searchTerm = computed(() => this.label() ?? this.element().textContent);
 
+  /** Whether the item is active. */
+  active: Signal<boolean>;
+
   /** The tree root. */
   readonly tree: Signal<Tree<V>> = computed(() => {
     if (this.parent() instanceof Tree) {
@@ -279,25 +282,22 @@ export class TreeItem<V> extends DeferredContentAware implements OnInit, OnDestr
     return (this.parent() as TreeItemGroup<V>).ownedBy().tree();
   });
 
-  /** Whether the item is active. */
-  readonly active = computed(() => this._pattern.active());
-
   /** Whether this item is currently expanded, returning null if not expandable. */
   readonly expanded = computed(() =>
     this._pattern.expandable() ? this._pattern.expanded() : null,
   );
 
   /** The level of the current item in a tree. */
-  readonly level = computed(() => this._pattern.level());
+  level: Signal<number>;
 
   /** The position of this item among its siblings (1-based). */
-  readonly posinset = computed(() => this._pattern.posinset());
+  posinset: Signal<number>;
 
   /** Whether the item is selected. */
-  readonly selected = computed(() => this._pattern.selected());
+  selected: Signal<boolean | undefined>;
 
   /** Whether this item is visible. */
-  readonly visible = computed(() => this._pattern.visible());
+  visible: Signal<boolean>;
 
   /** The UI pattern for this item. */
   _pattern: TreeItemPattern<V>;
@@ -336,6 +336,12 @@ export class TreeItem<V> extends DeferredContentAware implements OnInit, OnDestr
       children: computed(() => this._group()?.children() ?? []),
       hasChildren: computed(() => !!this._group()),
     });
+
+    this.active = this._pattern.active;
+    this.level = this._pattern.level;
+    this.posinset = this._pattern.posinset;
+    this.selected = this._pattern.selected;
+    this.visible = this._pattern.visible;
   }
 
   ngOnDestroy() {