titlelist.java

一个手机新闻查看系统

package com.wy.ch17;

import javax.microedition.lcdui.*;
import java.util.*;

public class TitleList extends List implements BackDisplay, CommandListener {
    private Displayable backDisplay; 
    private Command OKCommand;
    private Command QuitCommand;
    private Command BackCommand;
    private String titles[];
    private String ids[];
    private String title[];
    public TitleList(Displayable d, String t[]) {
        super("选择查看的新闻", List.IMPLICIT);
        backDisplay = d;
        titles = t;
        OKCommand = new Command("确定", Command.OK, 1);
        QuitCommand = new Command("退出", Command.EXIT, 2);
        BackCommand = new Command("后退", Command.BACK, 2);
        this.addCommand(QuitCommand);
        this.addCommand(BackCommand);
        if (titles.length == 0) {
            this.setTitle("没有相关新闻");
        } else {
            int halflength = titles.length / 2;
            ids = new String[halflength];
            title = new String[halflength];
            for (int i = 0; i < titles.length; i++) {
                ids[i / 2] = titles[i];
                i++;
                this.append(titles[i], null);
                title[i / 2] = titles[i];
            } //for
            this.setSelectCommand(OKCommand);
        } //else
        this.setCommandListener(this);
    }

    public void commandAction(Command command, Displayable displayable) {
        if (command == QuitCommand) {
            MainMIDlet.getInstance().notifyDestroyed();
        }
        if (command == BackCommand) {
            Display.getDisplay(MainMIDlet.getInstance()).setCurrent(
                    getDisplayable());
        }
        if (command == OKCommand) {
            int index = this.getSelectedIndex();
            String t = title[index];
            String id = ids[index];
            Alert a = new Alert("请稍等");
            a.setType(AlertType.INFO);
            a.setString("正在联网,请稍等");
            a.setTimeout(Alert.FOREVER);
            Display.getDisplay(MainMIDlet.getInstance()).setCurrent(a);
            new TitleThread(t, id, this).start();
        }
    }

    public void setDisplayable(Displayable back) {
        backDisplay = back;
    }

    public Displayable getDisplayable() {
        return backDisplay;
    }
}