Method _handleKeydown

src/material/chips/chip-grid.ts:448–495

Handles custom keyboard events.

(event: KeyboardEvent)

  /** Handles custom keyboard events. */
  override _handleKeydown(event: KeyboardEvent) {
    const keyCode = event.keyCode;
    const activeItem = this._keyManager.activeItem;

    if (keyCode === TAB) {
      if (
        this._chipInput?.focused &&
        hasModifierKey(event, 'shiftKey') &&
        this._chips.length &&
        !this._chips.last.disabled
      ) {
        event.preventDefault();

        if (activeItem) {
          this._keyManager.setActiveItem(activeItem);
        } else {
          this._focusLastChip();
        }
      } else {
        // Use the super method here since it doesn't check for the input
        // focused state. This allows focus to escape if there's only one
        // disabled chip left in the list.
        super._allowFocusEscape();
      }
    } else if (!this._chipInput?.focused) {
      // The up and down arrows are supposed to navigate between the individual rows in the grid.
      // We do this by filtering the actions down to the ones that have the same `_isPrimary`
      // flag as the active action and moving focus between them ourseles instead of delegating
      // to the key manager. For more information, see #29359 and:
      // https://www.w3.org/WAI/ARIA/apg/patterns/grid/examples/layout-grids/#ex2_label
      if ((keyCode === UP_ARROW || keyCode === DOWN_ARROW) && activeItem) {
        const eligibleActions = this._chipActions.filter(
          action => action._isPrimary === activeItem._isPrimary && !this._skipPredicate(action),
        );
        const currentIndex = eligibleActions.indexOf(activeItem);
        const delta = event.keyCode === UP_ARROW ? -1 : 1;

        event.preventDefault();
        if (currentIndex > -1 && this._isValidIndex(currentIndex + delta)) {
          this._keyManager.setActiveItem(eligibleActions[currentIndex + delta]);
        }
      } else {
        super._handleKeydown(event);
      }
    }

    this.stateChanges.next();
  }

  protected override _redirectDestroyedChipFocus() {
    if (this._lastDestroyedFocusedChipIndex === null) {