Blackberry - Create an application which will lock another application event

Question

Actually I want to make an application which will getGlobalEvent and control that event through another custom application. Is there any way to do so. Can i get global event from a particular application? Its like an application which will lock custom application in your blackberry, if you add following application in that locking app list and put password to access then when u try to open that application, it will ask for a password which u set in the locking app.

Answer 1

Common advices

• this should be background application
• in timer thread check current foreground application
• use custom global modal dialog to request password
• if password was wrong close app by simulating back key press or move app to background

Checking Application

Have to say, there can be several processes within one application so we will perform check based on module name:

 private String getModuleNameByProcessId(int id) {
  String result = null;
  ApplicationManager appMan = ApplicationManager.getApplicationManager();
  ApplicationDescriptor appDes[] = appMan.getVisibleApplications();
  for (int i = 0; i < appDes.length; i++) {
   if (appMan.getProcessId(appDes[i]) == id) {
    result = appDes[i].getModuleName();
    break;
   }
  }
  return result;
 }

Move application to Background?

Yep, there's no requestBackground() in ApplicationManager... so what you can do is requestForeground() on the next best app which is not on foreground, and this will move active app to background! You can even bring up Home Screen with requestForegroundForConsole():

 protected int switchForegroundModule() {
  int id = -1;
  ApplicationManager appMan = ApplicationManager.getApplicationManager();
  ApplicationDescriptor appDes[] = appMan.getVisibleApplications();
  for (int i = 0; i < appDes.length; i++) {
   if (!appDes[i].getModuleName().equalsIgnoreCase(STR_MODULE_NAME)) {
    id = appMan.getProcessId(appDes[i]);
    appMan.requestForeground(id);

    // give a time to foreground application
    try {
     Thread.sleep(1000);
    } catch (InterruptedException e) {     
     e.printStackTrace();
    }    
    break;
   }
  }
  return id;
 }

Global Dialog

Just to input password you can extend Dialog, it will be easier to consume result:

class PaswordDialog extends Dialog {
 private BasicEditField mPwdField = new BasicEditField();

 public PaswordDialog() {
  super(Dialog.D_OK_CANCEL, "Enter password", Dialog.CANCEL, null,
    Dialog.FIELD_HCENTER);
  add(mPwdField);
 }

 public String getPassword() {
  return mPwdField.getText();
 }
}

And password check will look like:

private boolean checkPassword() {
  boolean result = false;
  final PaswordDialog pwdDlg = new PaswordDialog();
  invokeAndWait(new Runnable() {
   public void run() {
    Ui.getUiEngine().pushGlobalScreen(pwdDlg, 0,
      UiEngine.GLOBAL_MODAL);
   }
  });
  result = ((Dialog.OK == pwdDlg.getSelectedValue()) && pwdDlg
    .getPassword().equalsIgnoreCase(STR_PASSWORD));
  return result;
 }

Put this all together

Sample to block Adress Book App:

public class LockMainApp extends Application {

 private static final String STR_MODULE_NAME = "net_rim_bb_addressbook_app";
 private static final String STR_PASSWORD = "12345";
 int mFGProcessId = -1;

 public LockMainApp() {
  Timer timer = new Timer();
  timer.schedule(mCheckForeground, 1000, 1000);
 }

 public static void main(String[] args) {
  LockMainApp app = new LockMainApp();
  app.enterEventDispatcher();
 }

 TimerTask mCheckForeground = new TimerTask() {
  public void run() {
   int id = ApplicationManager
       .getApplicationManager().getForegroundProcessId();
   if (id != mFGProcessId) {
    mFGProcessId= id;
    String moduleName = getModuleNameByProcessId(mFGProcessId);
    if (moduleName.equalsIgnoreCase(STR_MODULE_NAME)) {
     if (!checkPassword())
      mFGProcessId = switchForegroundModule();

    }
   }
  };
 };
}