waitcanvas.java

用J2ME实现简单电子邮件发送功能。 可以通过手机运行该程序

/* License
 * 
 * Copyright 1994-2004 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *  
 *  * Redistribution of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 * 
 *  * Redistribution in binary form must reproduce the above copyright notice,
 *      this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *  
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *  
 * You acknowledge that this software is not designed, licensed or intended
 * for use in the design, construction, operation or maintenance of any
 * nuclear facility. 
 */

import java.util.*;

import javax.microedition.lcdui.*;

public class WaitCanvas
    extends Canvas {
  private int mCount, mMaximum;
  private int mInterval;
  
  private int mWidth, mHeight, mX, mY, mRadius;
  private String mMessage;
  
  public WaitCanvas() {
    mCount = 0;
    mMaximum = 36;
    mInterval = 100;
    
    mWidth = getWidth();
    mHeight = getHeight();
    
    // Calculate the radius.
    int halfWidth = (mWidth - mRadius) / 2;
    int halfHeight = (mHeight - mRadius) / 2;
    mRadius = Math.min(halfWidth, halfHeight);
    
    // Calculate the location.
    mX = halfWidth - mRadius / 2;
    mY = halfHeight - mRadius / 2;

    // Create a Timer to update the display.
    TimerTask task = new TimerTask() {
      public void run() {
        mCount = (mCount + 1) % mMaximum;
        repaint();
      }
    };
    Timer timer = new Timer();
    timer.schedule(task, 0, mInterval);
  }
  
  public void setMessage(String s) {
    mMessage = s;
    repaint();
  }
  
  public void paint(Graphics g) {
    int theta = -(mCount * 360 / mMaximum);
    
    // Clear the whole screen.
    g.setColor(255, 255, 255);
    g.fillRect(0, 0, mWidth, mHeight);
    
    // Now draw the pinwheel.
    g.setColor(0, 0, 0);
    g.drawArc(mX, mY, mRadius, mRadius, 0, 360);
    g.fillArc(mX, mY, mRadius, mRadius, theta +  90, 90);
    g.fillArc(mX, mY, mRadius, mRadius, theta + 270, 90);
    
    // Draw the message, if there is a message.
    if (mMessage != null)
      g.drawString(mMessage, mWidth / 2, mHeight,
          Graphics.BOTTOM | Graphics.HCENTER);
  }
}