feat(cdk-experimental/radio): create radio group and button directives

Author: wagnermaciel

.ng-dev/commit-message.mts

@@ -13,6 +13,7 @@ export const commitMessage: CommitMessageConfig = {
     'cdk-experimental/combobox',
     'cdk-experimental/listbox',
     'cdk-experimental/popover-edit',
+    'cdk-experimental/radio',
     'cdk-experimental/scrolling',
     'cdk-experimental/selection',
     'cdk-experimental/table-scroll-container',

src/cdk-experimental/config.bzl

@@ -5,6 +5,7 @@ CDK_EXPERIMENTAL_ENTRYPOINTS = [
     "deferred-content",
     "listbox",
     "popover-edit",
+    "radio",
     "scrolling",
     "selection",
     "tabs",

src/cdk-experimental/radio/BUILD.bazel

@@ -0,0 +1,17 @@
+load("//tools:defaults.bzl", "ng_project")
+
+package(default_visibility = ["//visibility:public"])
+
+ng_project(
+    name = "radio",
+    srcs = glob(
+        ["**/*.ts"],
+        exclude = ["**/*.spec.ts"],
+    ),
+    deps = [
+        "//:node_modules/@angular/core",
+        "//src/cdk-experimental/ui-patterns",
+        "//src/cdk/a11y",
+        "//src/cdk/bidi",
+    ],
+)

src/cdk-experimental/radio/index.ts

@@ -0,0 +1,9 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+export * from './public-api';

src/cdk-experimental/radio/public-api.ts

@@ -0,0 +1,9 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+export {CdkRadioGroup, CdkRadioButton} from './radio';

src/cdk-experimental/radio/radio.ts

@@ -0,0 +1,178 @@
+/**
+ * @license
+ * Copyright Google LLC All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.dev/license
+ */
+
+import {
+  AfterViewInit,
+  booleanAttribute,
+  computed,
+  contentChildren,
+  Directive,
+  effect,
+  ElementRef,
+  inject,
+  input,
+  linkedSignal,
+  model,
+  signal,
+} from '@angular/core';
+import {RadioButtonPattern, RadioGroupPattern} from '../ui-patterns';
+import {Directionality} from '@angular/cdk/bidi';
+import {toSignal} from '@angular/core/rxjs-interop';
+import {_IdGenerator} from '@angular/cdk/a11y';
+
+/**
+ * A radio button group container.
+ *
+ * Radio groups are used to group multiple radio buttons or radio group labels so they function as
+ * a single form control. The CdkRadioGroup is meant to be used in conjunction with CdkRadioButton
+ * as follows:
+ *
+ * ```html
+ * <div cdkRadioGroup>
+ *   <label cdkRadioButton value="1">Option 1</label>
+ *   <label cdkRadioButton value="2">Option 2</label>
+ *   <label cdkRadioButton value="3">Option 3</label>
+ * </div>
+ * ```
+ */
+@Directive({
+  selector: '[cdkRadioGroup]',
+  exportAs: 'cdkRadioGroup',
+  host: {
+    'role': 'radiogroup',
+    'class': 'cdk-radio-group',
+    '[attr.tabindex]': 'pattern.tabindex()',
+    '[attr.aria-readonly]': 'pattern.readonly()',
+    '[attr.aria-disabled]': 'pattern.disabled()',
+    '[attr.aria-orientation]': 'pattern.orientation()',
+    '[attr.aria-activedescendant]': 'pattern.activedescendant()',
+    '(keydown)': 'pattern.onKeydown($event)',
+    '(pointerdown)': 'pattern.onPointerdown($event)',
+    '(focusin)': 'onFocus()',
+  },
+})
+export class CdkRadioGroup<V> implements AfterViewInit {
+  /** The directionality (LTR / RTL) context for the application (or a subtree of it). */
+  private readonly _directionality = inject(Directionality);
+
+  /** The CdkRadioButtons nested inside of the CdkRadioGroup. */
+  private readonly _cdkRadioButtons = contentChildren(CdkRadioButton, {descendants: true});
+
+  /** A signal wrapper for directionality. */
+  protected textDirection = toSignal(this._directionality.change, {
+    initialValue: this._directionality.value,
+  });
+
+  /** The RadioButton UIPatterns of the child CdkRadioButtons. */
+  protected items = computed(() => this._cdkRadioButtons().map(radio => radio.pattern));
+
+  /** Whether the radio group is vertically or horizontally oriented. */
+  orientation = input<'vertical' | 'horizontal'>('vertical');
+
+  /** Whether focus should wrap when navigating. */
+  wrap = input(false, {transform: booleanAttribute}); // Radio groups typically don't wrap
+
+  /** Whether disabled items in the group should be skipped when navigating. */
+  skipDisabled = input(true, {transform: booleanAttribute});
+
+  /** The focus strategy used by the radio group. */
+  focusMode = input<'roving' | 'activedescendant'>('roving');
+
+  /** Whether the radio group is disabled. */
+  disabled = input(false, {transform: booleanAttribute});
+
+  /** Whether the radio group is readonly. */
+  readonly = input(false, {transform: booleanAttribute});
+
+  /** The value of the currently selected radio button. */
+  value = model<V | null>(null);
+
+  /** The internal selection state for the radio group. */
+  private readonly _value = linkedSignal(() => (this.value() ? [this.value()!] : []));
+
+  /** The current index that has been navigated to. */
+  activeIndex = model<number>(0);
+
+  /** The RadioGroup UIPattern. */
+  pattern: RadioGroupPattern<V> = new RadioGroupPattern<V>({
+    ...this,
+    items: this.items,
+    value: this._value,
+    textDirection: this.textDirection,
+  });
+
+  /** Whether the radio group has received focus yet. */
+  private _hasFocused = signal(false);
+
+  /** Whether the radio buttons in the group have been initialized. */
+  private _isViewInitialized = signal(false);
+
+  constructor() {
+    effect(() => {
+      if (this._isViewInitialized() && !this._hasFocused()) {
+        this.pattern.setDefaultState();
+      }
+    });
+  }
+
+  ngAfterViewInit() {
+    this._isViewInitialized.set(true);
+  }
+
+  onFocus() {
+    this._hasFocused.set(true);
+  }
+}
+
+/** A selectable radio button in a CdkRadioGroup. */
+@Directive({
+  selector: '[cdkRadioButton]',
+  exportAs: 'cdkRadioButton',
+  host: {
+    'role': 'radio',
+    'class': 'cdk-radio-button',
+    '[class.cdk-active]': 'pattern.active()',
+    '[attr.tabindex]': 'pattern.tabindex()',
+    '[attr.aria-checked]': 'pattern.selected()',
+    '[attr.aria-disabled]': 'pattern.disabled()',
+  },
+})
+export class CdkRadioButton<V> {
+  /** A reference to the radio button element. */
+  private readonly _elementRef = inject(ElementRef);
+
+  /** The parent CdkRadioGroup. */
+  private readonly _cdkRadioGroup = inject(CdkRadioGroup);
+
+  /** A unique identifier for the radio button. */
+  private readonly _generatedId = inject(_IdGenerator).getId('cdk-radio-button-');
+
+  /** A unique identifier for the radio button. */
+  protected id = computed(() => this._generatedId);
+
+  /** The value associated with the radio button. */
+  protected value = input.required<V>();
+
+  /** The parent RadioGroup UIPattern. */
+  protected group = computed(() => this._cdkRadioGroup.pattern);
+
+  /** A reference to the radio button element to be focused on navigation. */
+  protected element = computed(() => this._elementRef.nativeElement);
+
+  /** Whether the radio button is disabled. */
+  disabled = input(false, {transform: booleanAttribute});
+
+  /** The RadioButton UIPattern. */
+  pattern = new RadioButtonPattern<V>({
+    ...this,
+    id: this.id,
+    value: this.value,
+    group: this.group,
+    element: this.element,
+  });
+}