itemstatelistenerdemo.java

J2ME高级用户界面的学习代码

//ItemStateListener.java

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

public class ItemStateListenerDemo extends MIDlet implements CommandListener
{
  private Command cmdExit =  new Command("Exit",Command.EXIT,1);
  private Form mForm;
  private TextField mTextField;
  private Gauge mGauge;
  private ChoiceGroup mChoiceGroup;
  private DateField mDateField;
  private StringItem mStringItem;
  private StringItem timeShow;

  public ItemStateListenerDemo()
  {
    String[] excChoices = {"Choice ONE","Choice TWO","Choice Three"};
    //Image imgChoices

    mForm = new Form("ItemStateListener Demostation");
    mTextField =  new TextField("Input"," ",50,TextField.ANY);
    mGauge = new Gauge("Power Show",true,5,0);
    mChoiceGroup =  new ChoiceGroup("Excusive Choices",Choice.EXCLUSIVE,excChoices,null);
    mDateField = new DateField("Time on the board is: ",DateField.DATE_TIME);
    mStringItem = new StringItem("The output is:","",Item.BUTTON);
    timeShow = new StringItem("The current time is:","");

    mForm.append(mTextField);
    mForm.append(mGauge);
    mForm.append(mChoiceGroup);
    mForm.append(mDateField);
    mForm.append(mStringItem);
    mForm.append(timeShow);

    ItemStateListener listener = new ItemStateListener()
    {
      public void itemStateChanged(Item mItem)
      {
        if(mItem == mTextField)
        {
          int len = mTextField.size();
          char[] charArray = new char[len];
          mTextField.getChars(charArray);
          mStringItem.setText(new String(charArray));
        }
        else if(mItem == mGauge)
        {
          int iValue = mGauge.getValue();
          switch(iValue)
          {
            case 0:mStringItem.setText("Worst!");break;
            case 1:mStringItem.setText("Worse...");break;
            case 2:mStringItem.setText("bad.");break;
            case 3:mStringItem.setText("meium");break;
            case 4:mStringItem.setText("Good!");break;
            case 5:mStringItem.setText("Excellent!!!");break;
            default:mStringItem.setText("Something wrong with it!");
          }
        }//else if
        else if(mItem == mDateField)
        {
          timeShow.setText(mDateField.getDate().toString());
        }
        else if(mItem == mChoiceGroup)
        {
          int choiceIndex =  mChoiceGroup.getSelectedIndex();
          switch(choiceIndex)
          {
            case 0:mStringItem.setText("Choice ONE was choosed!");break;
            case 1:mStringItem.setText("Choice TWO was choosed!");break;
            case 2:mStringItem.setText("Choice THREE was choosed!");break;
            default:mStringItem.setText("Something wrong with it!");
          }
       }
      }
    };
    mForm.setItemStateListener(listener);
    mForm.addCommand(cmdExit);
    mForm.setCommandListener(this);
  }

  public void startApp()
  {
    Display.getDisplay(this).setCurrent(mForm);
  }

  public void commandAction(Command c,Displayable d)
  {
    if(cmdExit == c)
    {
      destroyApp(false);
      notifyDestroyed();
    }
  }

  public void destroyApp(boolean unconditional){}
  public void pauseApp(){}
}