content: /*
   * Copyright (C) 2007 Esmertec AG.
   * Copyright (C) 2007 The Android Open Source Project
   *
   * 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 com.android.mms.dom;
  
  import java.util.ArrayList;
  
  import org.w3c.dom.Node;
  import org.w3c.dom.NodeList;
  
  public class NodeListImpl implements NodeList {
      private ArrayList<Node> mSearchNodes;
      private ArrayList<Node> mStaticNodes;
      private Node mRootNode;
      private String mTagName;
      private boolean mDeepSearch;
  
      /*
       * Internal Interface
       */
  
      /**
       * Constructs a NodeList by searching for all descendants or the direct
       * children of a root node with a given tag name.
       * @param rootNode The root <code>Node</code> of the search.
       * @param tagName The tag name to be searched for. If null, all descendants
       *              will be returned.
       * @param deep Limit the search to the direct children of rootNode if false,
       *              to all descendants otherwise.
       */
      public NodeListImpl(Node rootNode, String tagName, boolean deepSearch) {
          mRootNode = rootNode;
          mTagName  = tagName;
          mDeepSearch = deepSearch;
      }
  
      /**
       * Constructs a NodeList for a given static node list.
       * @param nodes The static node list.
       */
      public NodeListImpl(ArrayList<Node> nodes) {
          mStaticNodes = nodes;
      }
  
      /*
       * NodeListImpl Interface
       */
  
      public int getLength() {
          if (mStaticNodes == null) {
              fillList(mRootNode);
              return mSearchNodes.size();
          } else {
              return mStaticNodes.size();
          }
      }
  
      public Node item(int index) {
          Node node = null;
          if (mStaticNodes == null) {
              fillList(mRootNode);
              try {
                  node = mSearchNodes.get(index);
              } catch (IndexOutOfBoundsException e) {
                  // Do nothing and return null
              }
          } else {
              try {
                  node = mStaticNodes.get(index);
              } catch (IndexOutOfBoundsException e) {
                  // Do nothing and return null
              }
          }
          return node;
      }
  
      /**
       * A preorder traversal is done in the following order:
       * <ul>
       *   <li> Visit root.
       *   <li> Traverse children from left to right in preorder.
       * </ul>
       * This method fills the live node list.
       * @param The root of preorder traversal
       * @return The next match
       */
      private void fillList(Node node) {
          // (Re)-initialize the container if this is the start of the search.
          // Visit the root of this iteration otherwise.
          if (node == mRootNode) {
              mSearchNodes = new ArrayList<Node>();
          } else {
              if ((mTagName == null) || node.getNodeName().equals(mTagName)) {
                  mSearchNodes.add(node);
              }
          }
  
          // Descend one generation...
          node = node.getFirstChild();
  
          // ...and visit in preorder the children if we are in deep search
          // or directly add the children to the list otherwise.
          while (node != null) {
              if (mDeepSearch) {
                  fillList(node);
              } else {
                  if ((mTagName == null) || node.getNodeName().equals(mTagName)) {
                      mSearchNodes.add(node);
                  }
              }
              node = node.getNextSibling();
          }
      }
  }
  