urlnoderenderer.java

不错的网络蜘蛛

/*
 * UrlNodeRenderer.java
 *
 * Created on September 20, 2004, 11:14 AM
 */
import javax.swing.*;
import javax.swing.tree.*;
import java.awt.*;
import java.net.*;
/**
 * Custom tree node renderer.  If the url has a match, it will be drawn in blue
 * simple icons are used for all nodes. 
 *
 * @author  Mark Pendergast
 */
public class UrlNodeRenderer extends DefaultTreeCellRenderer{
   
    /**
     * icon used to display on the search tree
     */    
    public static Icon icon= null;
    /** Creates a new instance of UrlNodeRenderer */
    public UrlNodeRenderer() {
        
      icon = new ImageIcon(getClass().getResource("SPIDERWEB.gif")); 
    }
    /**
     * Sets the value of the current tree cell to value.
     * If selected is true, the cell will be drawn as if selected.
     * If expanded is true the node is currently expanded and if leaf is 
     * true the node represets a leaf and if hasFocus is true the node 
     * currently has focus. tree is the JTree the receiver is being 
     * configured for. Returns the Component that the renderer uses to draw the value. 
     *
     * Modified the TreeCellRender to match a specific nodes attributes. If
     * the node is a match, then blue is used for the text color.  Icon is customized
     *
     * @param tree the JTree being redrawn
     * @param value node in the tree
     * @param sel true if selected by the user
     * @param expanded true if path is expanded
     * @param leaf true if this node is a leaf
     * @param row row number (vertical position)
     * @param hasFocus true if it has the focus
     * @return the Component that the renderer uses to draw the value

     */   
    public Component getTreeCellRendererComponent(
                        JTree tree,
                        Object value,
                        boolean sel,
                        boolean expanded,
                        boolean leaf,
                        int row,
                        boolean hasFocus) {

        super.getTreeCellRendererComponent(
                        tree, value, sel,
                        expanded, leaf, row,
                        hasFocus);
        
        UrlTreeNode node = (UrlTreeNode)(((DefaultMutableTreeNode)value).getUserObject());
        if (node.isMatch()) // set color
            setForeground(Color.blue);
         else 
            setForeground(Color.black);
       
        if(icon != null)    // set a custom icon
        {
            setOpenIcon(icon);
            setClosedIcon(icon);
            setLeafIcon(icon);
        }
        

        return this;
    }

    
}