// Copyright 2008 The Closure Library Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS-IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

/**
 * @fileoverview Editor plugin to handle tab keys in lists to indent and
 * outdent.
 *
 * @author robbyw@google.com (Robby Walker)
 */

goog.provide('goog.editor.plugins.ListTabHandler');

goog.require('goog.dom');
goog.require('goog.dom.TagName');
goog.require('goog.editor.Command');
goog.require('goog.editor.plugins.AbstractTabHandler');
goog.require('goog.iter');



/**
 * Plugin to handle tab keys in lists to indent and outdent.
 * @constructor
 * @extends {goog.editor.plugins.AbstractTabHandler}
 * @final
 */
goog.editor.plugins.ListTabHandler = function() {
  goog.editor.plugins.AbstractTabHandler.call(this);
};
goog.inherits(
    goog.editor.plugins.ListTabHandler, goog.editor.plugins.AbstractTabHandler);


/** @override */
goog.editor.plugins.ListTabHandler.prototype.getTrogClassId = function() {
  return 'ListTabHandler';
};


/** @override */
goog.editor.plugins.ListTabHandler.prototype.handleTabKey = function(e) {
  var range = this.getFieldObject().getRange();
  if (goog.dom.getAncestorByTagNameAndClass(
          range.getContainerElement(), goog.dom.TagName.LI) ||
      goog.iter.some(range, function(node) {
        return node.tagName == goog.dom.TagName.LI;
      })) {
    this.getFieldObject().execCommand(
        e.shiftKey ? goog.editor.Command.OUTDENT : goog.editor.Command.INDENT);
    e.preventDefault();
    return true;
  }

  return false;
};