/**
 * Copyright 2008 Google Inc.
 *
 * 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.
 *
 */

package org.waveprotocol.wave.client.editor.content.misc;

import org.waveprotocol.wave.client.editor.ElementHandlerRegistry;
import org.waveprotocol.wave.client.editor.NodeEventHandlerImpl;
import org.waveprotocol.wave.client.editor.content.ContentElement;
import org.waveprotocol.wave.client.editor.event.EditorEvent;
import org.waveprotocol.wave.client.editor.selection.content.SelectionUtil;

/**
 * An element that gets deleted by backspace and delete key events in the
 * expected manner.
 *
 * It may be useful as a base class for other handlers as well.
 *
 * @author danilatos@google.com (Daniel Danilatos)
 */
public class ChunkyElementHandler extends NodeEventHandlerImpl {
  /**
   * Instance, exposed for delegation if needed.
   */
  public static final ChunkyElementHandler INSTANCE = new ChunkyElementHandler();

  /** Register a self-deleting element */
  public static void register(String tagName, final ElementHandlerRegistry registry) {
    registry.registerEventHandler(tagName, INSTANCE);
  }

  @Override
  public boolean handleBackspaceAfterNode(ContentElement element, EditorEvent event) {
    element.getMutableDoc().deleteNode(element);
    return true;
  }


  @Override
  public boolean handleDeleteBeforeNode(ContentElement element, EditorEvent event) {
    element.getMutableDoc().deleteNode(element);
    return true;
  }

  @Override
  public boolean handleLeftAfterNode(ContentElement element, EditorEvent event) {
    SelectionUtil.placeCaretBeforeElement(element.getSelectionHelper(), element);
    return true;
  }

  @Override
  public boolean handleRightBeforeNode(ContentElement element, EditorEvent event) {
    SelectionUtil.placeCaretAfterElement(element.getSelectionHelper(), element);
    return true;
  }
}