gaugedemo.java

JAVA编程百例书中各章节的所有例子的源代码,包括套接字编程

package ch09.section01;

import javax.microedition.lcdui.*;

//进度条实例类
public class GaugeDemo
    extends BaseDemo {
  //创建进度条实例
  public GaugeDemo() {
    super("进度条控件实例");
    append("第一个进度条可响应用户，第二个进度条不响应用户，取值范围从0至100");
    append(new Gauge("交互进度条", true, 30, 0));
    //此类实现一个自动变化的非交互进度条
    class NoneInteractiveGauge
        extends Gauge
        implements Runnable {
      //每次变换的幅度
      private int movement = 1;
      public NoneInteractiveGauge() {
        super("非交互进度条", false, 30, 0);
        new Thread(this).start();
      }

      //此方法实现进度条从左至右变化
      public void run() {
        UIDemo midlet = UIDemo.getInstance();
        while (midlet.getCurrentDemo() == null) {
          Thread.currentThread().yield();
        }
        while ( (midlet.getCurrentDemo() != null) &&
               (midlet.getCurrentDemo() instanceof GaugeDemo)) {
          //判断变化方向
          int newValue = getValue() + movement;
          if (newValue >= 30) {
            movement = -1;
          }
          else {
            if (newValue <= 0) {
              movement = 1;
            }
          }
          setValue(newValue);
          try {
            Thread.currentThread().sleep(1000);
          }
          catch (InterruptedException err) {}
        }
      }
    }

    append(new NoneInteractiveGauge());
  }
}