Class MatButtonToggleGroup

src/material/button-toggle/button-toggle.ts:140–545

  exportAs: 'matButtonToggleGroup',
})
export class MatButtonToggleGroup implements ControlValueAccessor, OnInit, AfterContentInit {
  private _changeDetector = inject(ChangeDetectorRef);
  private _dir = inject(Directionality, {optional: true});

  private _multiple = false;
  private _disabled = false;
  private _disabledInteractive = false;
  private _selectionModel!: SelectionModel<MatButtonToggle>;

  /**
   * Reference to the raw value that the consumer tried to assign. The real
   * value will exclude any values from this one that don't correspond to a
   * toggle. Useful for the cases where the value is assigned before the toggles
   * have been initialized or at the same that they're being swapped out.
   */
  private _rawValue: any;

  /**
   * The method to be called in order to update ngModel.
   * Now `ngModel` binding is not supported in multiple selection mode.
   */
  _controlValueAccessorChangeFn: (value: any) => void = () => {};

  /** onTouch function registered via registerOnTouch (ControlValueAccessor). */
  _onTouched: () => any = () => {};

  /** Child button toggle buttons. */
  @ContentChildren(forwardRef(() => MatButtonToggle), {
    // Note that this would technically pick up toggles
    // from nested groups, but that's not a case that we support.
    descendants: true,
  })
  _buttonToggles!: QueryList<MatButtonToggle>;

  /** The appearance for all the buttons in the group. */
  @Input() appearance: MatButtonToggleAppearance;

  /** `name` attribute for the underlying `input` element. */
  @Input()
  get name(): string {
    return this._name;
  }
  set name(value: string) {
    this._name = value;
    this._markButtonsForCheck();
  }
  private _name = inject(_IdGenerator).getId('mat-button-toggle-group-');

  /** Whether the toggle group is vertical. */
  @Input({transform: booleanAttribute}) vertical: boolean = false;

  /** Value of the toggle group. */
  @Input()
  get value(): any {
    const selected = this._selectionModel ? this._selectionModel.selected : [];

    if (this.multiple) {
      return selected.map(toggle => toggle.value);