import javax.microedition.lcdui.ChoiceGroup;
import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.CommandListener;
import javax.microedition.lcdui.Display;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.Item;
import javax.microedition.lcdui.ItemStateListener;
import javax.microedition.midlet.MIDlet;

public class CityMidlet extends MIDlet implements CommandListener,ItemStateListener{
    private Display display;
    private Form form;
    private Command back;
    private ChoiceGroup province;
    private ChoiceGroup city;
    private String[][] provinceAndCity;
    
    public CityMidlet() {
        display = Display.getDisplay(this);
        provinceAndCity = new String[][]{{"直辖市","北京","上海","天津","重庆"},{"特别行政区","香港","澳门"},{"黑龙江","哈尔滨","齐齐哈尔","牡丹江","大庆","伊春","双鸭山","鹤岗","鸡西","佳木斯","七台河","黑河","绥化","大兴安岭"}};
        
        form = new Form("新增城市");
        back = new Command("返回",Command.BACK,1);
        province = new ChoiceGroup("省份：",ChoiceGroup.POPUP);
        city = new ChoiceGroup("城市：",ChoiceGroup.POPUP);
        province.append("请选择", null);

        for(int i = 0; i < provinceAndCity.length; i++)
            province.append(provinceAndCity[i][0], null);
        city.append("请选择", null);
        form.append(province);
        form.append(city);
        form.addCommand(back);
        form.setCommandListener(this);
    }

    public void startApp(){
        display.setCurrent(form);
    }
    
    public void pauseApp(){
    }

    public void destroyApp(boolean arg0){
    }
    
    public void itemStateChanged(Item item){
        if(item == province){
            int selected = province.getSelectedIndex();
            System.out.println(selected);
            if(selected == 0)
                return;
            else{
                city.deleteAll();
                city.append("请选择", null);
                for(int i = 1; i < provinceAndCity[selected - 1].length; i++)
                    city.append(provinceAndCity[selected - 1][i], null); 
            }
        }
        
    }
    
    public void commandAction(Command c, Displayable dpa) {

    }
}