testdnd.java

北大Java 语言程序设计 ppt课件及源码

/**
 * The tester class for the DNDList. This class creates the lists, 
 * positions them in a frame, populates the list with the default 
 * data.
 *
 * @version 1.0
 *
 */

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;


public class TestDND
{
  public static void main (String args[]) {
    TestDND testDND = new TestDND();
}

 /**
  * constructor
  * creates the frame, the lists in it and sets the data in the lists
  */
  
 public TestDND()
 {   
    JFrame f = new JFrame("Drag and Drop Lists");
    
    DNDList sourceList = new DNDList();
    
    // add data to the source List
    DefaultListModel sourceModel = new DefaultListModel();
    
    sourceModel.addElement( "Source Item1");
    sourceModel.addElement( "Source Item2");
    sourceModel.addElement( "Source Item3");
    sourceModel.addElement( "Source Item4");
    
    // gets the panel with the List and a heading for the List
    JPanel sourcePanel = getListPanel(sourceList, "SourceList", sourceModel); 
    
    DNDList targetList = new DNDList();
    
    // add data to the target List 
    DefaultListModel targetModel = new DefaultListModel();
    
    targetModel.addElement( "Target Item1");
    targetModel.addElement( "Target Item2");
    targetModel.addElement( "Target Item3");
    targetModel.addElement( "Target Item4");
    
    JPanel targetPanel = getListPanel(targetList, "TargetList", targetModel); 
    JPanel mainPanel = new JPanel();
	mainPanel.setLayout(new BoxLayout(mainPanel, BoxLayout.X_AXIS));
    mainPanel.add( sourcePanel );
    mainPanel.add( targetPanel );
    
    f.getContentPane().add( mainPanel );
    f.setSize (300, 300);
    f.addWindowListener (new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    f.setVisible (true);
  }

  /**
   * a convenience method
   * used for positioning of the ListBox and the Label.
   * 
   * @param list  - the special DND List
   * @param labelName - the heading for the list
   * @param listModel - model for the list
   */
 
  private JPanel getListPanel(DNDList list, String labelName, DefaultListModel listModel ){  
        JPanel listPanel = new JPanel();
        JScrollPane scrollPane = new JScrollPane(list);
        
        list.setModel(listModel);   
        JLabel nameListName = new JLabel(labelName );
        
        listPanel.setLayout( new BorderLayout());
        listPanel.add(nameListName, BorderLayout.NORTH);
        listPanel.add( scrollPane, BorderLayout.CENTER);
       
        return listPanel;     
  }
  
}