vsx2.java

java swing 开发代码

// VSX2.java
// VSX2: A <b>Reasonably</b> Simple XML utility class.
// Currently this class has two main methods: parse() and write().
// Both work with the TreeModel class and are meant to help you
// view XML documents with JTree.  This version will embed icons
// and tool tip text in nodes if <code>icon</code> or
// <code>tiptext</code> attributes are found in the tag.
//

package	jswing.ch17;

import javax.swing.*;
import javax.swing.tree.*;
import java.io.*;
import org.xml.sax.*;
import org.xml.sax.helpers.*;
import javax.xml.parsers.*;

public class VSX2 {


  public TreeModel parse(String filename) {
    SAXParserFactory factory = SAXParserFactory.newInstance();
    XMLIconTreeHandler handler = new XMLIconTreeHandler();
    try {
      // Parse the input
      SAXParser saxParser = factory.newSAXParser();
      saxParser.parse( new File(filename), handler);
    }
    catch (Exception e) {
      System.err.println("File Read Error: " + e);
      e.printStackTrace();
      return new DefaultTreeModel(new DefaultMutableTreeNode("error"));
    }
    return new DefaultTreeModel(handler.getRoot());
  }

  public static class XMLIconTreeHandler extends DefaultHandler {
    private DefaultMutableTreeNode root, currentNode;  
    public DefaultMutableTreeNode getRoot() {
      return root;
    }

    // SAX Parser Handler methods...
    public void startElement(String namespaceURI,
                             String lName, // local name
                             String qName, // qualified name
                             Attributes attrs)
    throws SAXException
    {
      String eName = lName; // element name
      if ("".equals(eName)) eName = qName;
      ITag t = new ITag(eName, attrs);
      DefaultMutableTreeNode newNode = new DefaultMutableTreeNode(t);
      if (currentNode == null) {
        root = newNode;
      }
      else {
        // must not be the root node...
        currentNode.add(newNode);
      }
      currentNode = newNode;
    }

    public void endElement(String namespaceURI,
                           String sName, // simple name
                           String qName  // qualified name
                          )
    throws SAXException
    {
      currentNode = (DefaultMutableTreeNode)currentNode.getParent();
    }

    public void characters(char buf[], int offset, int len) throws SAXException {
      String s = new String(buf, offset, len).trim();
      ((ITag)currentNode.getUserObject()).addData(s);
    }
  }

  public static class ITag implements IconAndTipCarrier {
    private String name;
    private String data;
    private Attributes attr;
    private Icon icon;
    private String tipText;

    public ITag(String n, Attributes a) { 
      name = n; 
      attr = a;
      for (int i = 0; i < attr.getLength(); i++) {
        String aname = attr.getQName(i);
        String value = attr.getValue(i);
        if (aname.equals("icon")) {
          tipText = value;
	  icon = new ImageIcon(value);
	  break;
        }
      }
    }

    public String getName() { return name; }
    public Attributes getAttributes() { return attr; }
    public void setData(String d) { data = d; }
    public String getData() { return data; }
    public String getToolTipText() { return tipText; }
    public Icon getIcon() { return icon; }

    public void addData(String d) {
      if (data == null) {
        setData(d);
      }
      else {
        data += d;
      }
    }

    public String getAttributesAsString() {
      StringBuffer buf = new StringBuffer(256);
      for (int i = 0; i < attr.getLength(); i++) {
        buf.append(attr.getQName(i));
        buf.append("=\"");
        buf.append(attr.getValue(i));
        buf.append("\"");
      }
      return buf.toString();
    }

    public String toString() {
      String a = getAttributesAsString();
      return name + ": " + a + (data == null ? "" :" (" + data + ")");
    }
  }

  public static void main(String args[]) {
    if (args.length != 1) {
      System.err.println("Usage is: java VSX2 testfile.xml");
      System.exit(1);
    }
    JFrame frame = new JFrame("Tree Renderer Test");
    VSX2 parser = new VSX2();
    JTree tree = new JTree(parser.parse(args[0]));

    // Steal the default icons from the default renderer...
    DefaultTreeCellRenderer rend1 = new DefaultTreeCellRenderer();
    IconAndTipRenderer rend2 = new IconAndTipRenderer(
      rend1.getOpenIcon(),
      rend1.getClosedIcon(),
      rend1.getLeafIcon());
    tree.setCellRenderer(rend2);
    ToolTipManager.sharedInstance().registerComponent(tree);

    frame.getContentPane().add(new JScrollPane(tree));
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setSize(300,400);
    frame.setVisible(true);
  }
}