Mapping Commands : Event Command « J2ME « Java






Mapping Commands

Mapping Commands
/*--------------------------------------------------
* MappingCommands.java
*
* Example from the book:     Core J2ME Technology
* Copyright John W. Muchow   http://www.CoreJ2ME.com
* You may use/modify for any non-commercial purpose
*-------------------------------------------------*/
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class MappingCommands extends MIDlet implements CommandListener
{
  private Display display;      // Reference to Display object for this MIDlet
  private Form fmMain;          // Main Form  
  private TextBox tbHelp;       // Textbox to display help message
  private Command cmExit;       // Exit the MIDlet
  private Command cmHelp;       // Ask for Help
  private Command cmBack;       // Go "back" to the main form

  public MappingCommands()
  {
    display = Display.getDisplay(this);
    
    cmHelp = new Command("Help", Command.HELP, 1);
    cmBack = new Command("Back", Command.BACK, 1);
    cmExit = new Command("Exit", Command.EXIT, 1);
    
    // Create the Form, add Commands, listen for events
    fmMain = new Form("Core J2ME");
    fmMain.addCommand(cmExit);
    fmMain.addCommand(cmHelp);    
    fmMain.setCommandListener(this);
            
    // Create the help Textbox with a maximum of 25 characters
    tbHelp = new TextBox("Help", "Help text here...", 25, 0);
    tbHelp.addCommand(cmBack);
    tbHelp.setCommandListener(this);      
 
  }

  // Called by application manager to start the MIDlet.
  public void startApp()
  {
    display.setCurrent(fmMain);
  }

  // A required method
  public void pauseApp()
  { }

  // A required method
  public void destroyApp(boolean unconditional)
  { }

  // Process events
  public void commandAction(Command c, Displayable s)
  {
    if (c == cmExit)
    {
      destroyApp(false);
      notifyDestroyed();
    }
    else if (c == cmHelp)
      display.setCurrent(tbHelp);     
    else if (c == cmBack)
      display.setCurrent(fmMain);     
  }
}


           
       








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