domecho05.java

XML_JAVA指南 书籍语言： 简体中文 书籍类型： 程序设计 授权方式： 免费软件 书籍大小： 377 KB

        "slideshow",
        "slide",
        "title",         // For slideshow #1
        "slide-title",   // For slideshow #10
        "item",
    };
    boolean treeElement(String elementName) {
      for (int i=0; i<treeElementNames.length; i++) {
        if ( elementName.equals(treeElementNames[i]) ) return true;
      }
      return false;
    }

    // This class wraps a DOM node and returns the text we want to
    // display in the tree. It also returns children, index values,
    // and child counts.
    public class AdapterNode 
    { 
      org.w3c.dom.Node domNode;

      // Construct an Adapter node from a DOM node
      public AdapterNode(org.w3c.dom.Node node) {
        domNode = node;
      }

      // Return a string that identifies this node in the tree
      // *** Refer to table at top of org.w3c.dom.Node ***
      public String toString() {
        String s = typeName[domNode.getNodeType()];
        String nodeName = domNode.getNodeName();
        if (! nodeName.startsWith("#")) {
           s += ": " + nodeName;
        }
        if (compress) {
           String t = content().trim();
           int x = t.indexOf("\n");
           if (x >= 0) t = t.substring(0, x);
           s += " " + t;
           return s;
        }
        if (domNode.getNodeValue() != null) {
           if (s.startsWith("ProcInstr")) 
              s += ", "; 
           else 
              s += ": ";
           // Trim the value to get rid of NL's at the front
           String t = domNode.getNodeValue().trim();
           int x = t.indexOf("\n");
           if (x >= 0) t = t.substring(0, x);
           s += t;
        }
        return s;
      }

      public String content() {
        String s = "";
        org.w3c.dom.NodeList nodeList = domNode.getChildNodes();
        for (int i=0; i<nodeList.getLength(); i++) {
          org.w3c.dom.Node node = nodeList.item(i);
          int type = node.getNodeType();
          AdapterNode adpNode = new AdapterNode(node); //inefficient, but works
          if (type == ELEMENT_TYPE) {
            // Skip subelements that are displayed in the tree.   
            if ( treeElement(node.getNodeName()) ) continue;

            // EXTRA-CREDIT HOMEWORK:
            //   Special case the SLIDE element to use the TITLE text
            //   and ignore TITLE element when constructing the tree.

            // EXTRA-CREDIT
            //   Convert ITEM elements to html lists using
            //   <ul>, <li>, </ul> tags

            s += "<" + node.getNodeName() + ">";
            s += adpNode.content();
            s += "</" + node.getNodeName() + ">";
          } else if (type == TEXT_TYPE) {
            s += node.getNodeValue();
          } else if (type == ENTITYREF_TYPE) {
            // The content is in the TEXT node under it
            s += adpNode.content();
          } else if (type == CDATA_TYPE) {
            // The "value" has the text, same as a text node.
            //   while EntityRef has it in a text node underneath.
            //   (because EntityRef can contain multiple subelements)
            // Convert angle brackets and ampersands for display
            StringBuffer sb = new StringBuffer( node.getNodeValue() );
            for (int j=0; j<sb.length(); j++) {
              if (sb.charAt(j) == '<') {
                sb.setCharAt(j, '&');
                sb.insert(j+1, "lt;");
                j += 3;
              } else if (sb.charAt(j) == '&') {
                sb.setCharAt(j, '&');
                sb.insert(j+1, "amp;");
                j += 4;
              }
            }
            s += "<pre>" + sb + "\n</pre>";
          }
           // Ignoring these:
           //   ATTR_TYPE      -- not in the DOM tree
           //   ENTITY_TYPE    -- does not appear in the DOM
           //   PROCINSTR_TYPE -- not "data"
           //   COMMENT_TYPE   -- not "data"
           //   DOCUMENT_TYPE  -- Root node only. No data to display.
           //   DOCTYPE_TYPE   -- Appears under the root only
           //   DOCFRAG_TYPE   -- equiv. to "document" for fragments
           //   NOTATION_TYPE  -- nothing but binary data in here
        }
        return s;
      }

      /*
       * Return children, index, and count values
       */
      public int index(AdapterNode child) {
        //System.err.println("Looking for index of " + child);
        int count = childCount();
        for (int i=0; i<count; i++) {
          AdapterNode n = this.child(i);
          if (child.domNode == n.domNode) return i;
        }
        return -1; // Should never get here.
      }

      public AdapterNode child(int searchIndex) {
        //Note: JTree index is zero-based. 
        org.w3c.dom.Node node = 
             domNode.getChildNodes().item(searchIndex);
        if (compress) {
          // Return Nth displayable node
          int elementNodeIndex = 0;
          for (int i=0; i<domNode.getChildNodes().getLength(); i++) {
            node = domNode.getChildNodes().item(i);
            if (node.getNodeType() == ELEMENT_TYPE 
            && treeElement( node.getNodeName() )
            && elementNodeIndex++ == searchIndex) {
               break; 
            }
          }
        }
        return new AdapterNode(node); 
      }

      public int childCount() {
        if (!compress) {
          // Indent this
          return domNode.getChildNodes().getLength();  
        } 
        int count = 0;
        for (int i=0; i<domNode.getChildNodes().getLength(); i++) {
           org.w3c.dom.Node node = domNode.getChildNodes().item(i); 
           if (node.getNodeType() == ELEMENT_TYPE
           && treeElement( node.getNodeName() )) 
           {
             // Note: 
             //   Have to check for proper type. 
             //   The DOCTYPE element also has the right name
             ++count;
           }
        }
        return count;
      }
    }

    // This adapter converts the current Document (a DOM) into 
    // a JTree model. 
    public class DomToTreeModelAdapter 
      implements javax.swing.tree.TreeModel 
    {
      // Basic TreeModel operations
      public Object  getRoot() {
        //System.err.println("Returning root: " +document);
        return new AdapterNode(document);
      }
      public boolean isLeaf(Object aNode) {
        // Determines whether the icon shows up to the left.
        // Return true for any node with no children
        AdapterNode node = (AdapterNode) aNode;
        if (node.childCount() > 0) return false;
        return true;
      }
      public int     getChildCount(Object parent) {
        AdapterNode node = (AdapterNode) parent;
        return node.childCount();
      }
      public Object getChild(Object parent, int index) {
        AdapterNode node = (AdapterNode) parent;
        return node.child(index);
      }
      public int getIndexOfChild(Object parent, Object child) {
        AdapterNode node = (AdapterNode) parent;
        return node.index((AdapterNode) child);
      }
      public void valueForPathChanged(TreePath path, Object newValue) {
        // Null. We won't be making changes in the GUI
        // If we did, we would ensure the new value was really new,
        // adjust the model, and then fire a TreeNodesChanged event.
      }

      /*
       * Use these methods to add and remove event listeners.
       * (Needed to satisfy TreeModel interface, but not used.)
       */
      private Vector listenerList = new Vector();
      public void addTreeModelListener(TreeModelListener listener) {
        if ( listener != null 
        && ! listenerList.contains( listener ) ) {
           listenerList.addElement( listener );
        }
      }
      public void removeTreeModelListener(TreeModelListener listener) {
        if ( listener != null ) {
           listenerList.removeElement( listener );
        }
      }

      // Note: Since XML works with 1.1, this example uses Vector.
      // If coding for 1.2 or later, though, I'd use this instead:
      //   private List listenerList = new LinkedList();
      // The operations on the List are then add(), remove() and
      // iteration, via:
      //  Iterator it = listenerList.iterator();
      //  while ( it.hasNext() ) {
      //    TreeModelListener listener = (TreeModelListener)it.next();
      //    ...
      //  }

      /*
       * Invoke these methods to inform listeners of changes.
       * (Not needed for this example.)
       * Methods taken from TreeModelSupport class described at 
       *   http://java.sun.com/products/jfc/tsc/articles/jtree/index.html
       * That architecture (produced by Tom Santos and Steve Wilson)
       * is more elegant. I just hacked 'em in here so they are
       * immediately at hand.
       */
      public void fireTreeNodesChanged( TreeModelEvent e ) {
        Enumeration listeners = listenerList.elements();
        while ( listeners.hasMoreElements() ) {
          TreeModelListener listener = 
            (TreeModelListener)listeners.nextElement();
          listener.treeNodesChanged( e );
        }
      } 
      public void fireTreeNodesInserted( TreeModelEvent e ) {
        Enumeration listeners = listenerList.elements();
        while ( listeners.hasMoreElements() ) {
           TreeModelListener listener =
             (TreeModelListener)listeners.nextElement();
           listener.treeNodesInserted( e );
        }
      }   
      public void fireTreeNodesRemoved( TreeModelEvent e ) {
        Enumeration listeners = listenerList.elements();
        while ( listeners.hasMoreElements() ) {
          TreeModelListener listener = 
            (TreeModelListener)listeners.nextElement();
          listener.treeNodesRemoved( e );
        }
      }   
      public void fireTreeStructureChanged( TreeModelEvent e ) {
        Enumeration listeners = listenerList.elements();
        while ( listeners.hasMoreElements() ) {
          TreeModelListener listener =
            (TreeModelListener)listeners.nextElement();
          listener.treeStructureChanged( e );
        }
      }
    }
}