refactor: move angular source to /packages rather than modules/@angular

packages/forms/src/directives/checkbox_value_accessor.ts

@@ -0,0 +1,50 @@
+/**
+ * @license
+ * Copyright Google Inc. 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.io/license
+ */
+
+import {Directive, ElementRef, Renderer, forwardRef} from '@angular/core';
+
+import {ControlValueAccessor, NG_VALUE_ACCESSOR} from './control_value_accessor';
+
+export const CHECKBOX_VALUE_ACCESSOR: any = {
+  provide: NG_VALUE_ACCESSOR,
+  useExisting: forwardRef(() => CheckboxControlValueAccessor),
+  multi: true,
+};
+
+/**
+ * The accessor for writing a value and listening to changes on a checkbox input element.
+ *
+ *  ### Example
+ *  ```
+ *  <input type="checkbox" name="rememberLogin" ngModel>
+ *  ```
+ *
+ *  @stable
+ */
+@Directive({
+  selector:
+      'input[type=checkbox][formControlName],input[type=checkbox][formControl],input[type=checkbox][ngModel]',
+  host: {'(change)': 'onChange($event.target.checked)', '(blur)': 'onTouched()'},
+  providers: [CHECKBOX_VALUE_ACCESSOR]
+})
+export class CheckboxControlValueAccessor implements ControlValueAccessor {
+  onChange = (_: any) => {};
+  onTouched = () => {};
+
+  constructor(private _renderer: Renderer, private _elementRef: ElementRef) {}
+
+  writeValue(value: any): void {
+    this._renderer.setElementProperty(this._elementRef.nativeElement, 'checked', value);
+  }
+  registerOnChange(fn: (_: any) => {}): void { this.onChange = fn; }
+  registerOnTouched(fn: () => {}): void { this.onTouched = fn; }
+
+  setDisabledState(isDisabled: boolean): void {
+    this._renderer.setElementProperty(this._elementRef.nativeElement, 'disabled', isDisabled);
+  }
+}