/*
 * Copyright (c) 2010, 2025 BSI Business Systems Integration AG
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 */
import {AbstractTreeNavigationKeyStroke, keys, Tree, TreeNode} from '../../index';

export class TreeNavigationDownKeyStroke extends AbstractTreeNavigationKeyStroke {

  constructor(tree: Tree, modifierBitMask: number) {
    super(tree, modifierBitMask);
    this.which = [keys.DOWN];
    this.renderingHints.text = '↓';
  }

  protected override _computeNewSelection(currentNode: TreeNode): TreeNode {
    let nodes = this.field.visibleNodesFlat;
    if (nodes.length === 0) {
      return;
    }
    if (!currentNode) {
      return nodes[0];
    }
    return nodes[nodes.indexOf(currentNode) + 1];
  }
}