responsedialog.java

ALGAE是一个快速创建算法演示的框架。目前支持的算法实现语言包括java和c

package edu.odu.cs.zeil.AlgAE;

import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Dialog;
import java.awt.Event;
import java.awt.Frame;
import java.awt.Panel;
import java.awt.TextArea;
import java.awt.TextField;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import edu.odu.cs.zeil.AlgAE.MessageListener;

/**
 *  Dialog box displaying for displaying a prompt and awaiting a response.
 *  @author Steven J. Zeil
 */
public class ResponseDialog extends Dialog
{
  
  private TextField response;
  private MessageListener notify;
  private boolean sent;
    

  /**
   *  Constructor
   *  @param theParent   Window from which this dialog is issued.
   *  @param text        Text to display in dialog
   */
  public ResponseDialog  (Frame theParent, String text,
			  MessageListener notifyWhenClosed)
  {
    super (theParent, "AlgAE", false);
    notify = notifyWhenClosed;
    sent = false;
    Panel central = new Panel();
    central.setLayout (new BorderLayout());

    int maxWidth = 0;
    int width = 0;
    int nLines = 0;
    int pos = 0;
    int endLinePos = 0;
    
    while (endLinePos >= 0)
      {
	++nLines;
	endLinePos = text.indexOf(10, pos);
	if (endLinePos >= 0)
	  width = endLinePos - pos;
	else
	  width = text.length() - pos;
	
	maxWidth =  (width > maxWidth) ? width : maxWidth;
	pos = endLinePos + 1;
      }
    
    TextArea msg = new TextArea (text, nLines, maxWidth,
				 TextArea.SCROLLBARS_NONE);
    msg.setEditable(false);
    central.add ("Center", msg);

    response = new TextField(20);
    response.setEditable(true);
    central.add ("South", response);

    add ("Center", central);
    
    Button ok = new Button ("OK");
    ok.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {
	  sendResponse();
	}});
    add ("South", ok);

    addWindowListener(new WindowAdapter() {
      public void windowActivated(WindowEvent e) {response.requestFocus();}
      public void windowClosing(WindowEvent e) {
	  sendResponse();
      }
    });

    response.addKeyListener(new KeyAdapter() {
      public void keyPressed(KeyEvent e) {
	if (e.getKeyCode() == KeyEvent.VK_ENTER)
	  {
	    sendResponse();
	  }
	}});
 
    pack();
    response.requestFocus();
    show();
  }


    public void sendResponse()
    {
      if (!sent)
	{
	  sent = true;
	  setVisible(false);
	  notify.messageReceived(getText(), null);
	  dispose();
	}
    }
    

  /**
   *  Get the text currently in the editable response field.
   */
  public String getText()
  {
    String reply = response.getText();
    reply.trim();
    return reply;
  }
  

}