BlackBerry Application Development Guide monitors changes to UI objects (1)

UI EventListeners allows applications to respond to changes to a UI object. There are three types of UI event listeners:

Listen for field attribute changes

To monitor field changes, implement the FieldChangeListener interface. Call setChangeListener () to assign your implementation to a field.

 
 

  
  
private class  
  
  
FieldListener  implements implements implements  
  
  
implements  
  
  
FieldChangeListener  {  
  
  
public void  
  
  
fieldChanged(Field ,  int context)  {  
  
  
if  
  
  
(context  !=  FieldChangeListener.PROGRAMMATIC)  {  
  
  
//  Perform  action  if  user  changed  field.  
  
  
}  
  
  
else {  
  
  
//  Perform  action  if  application  changed  field.  
  
  
}  
  
  
}  
  
  
}  
  
  
//  ...  
  
  
FieldListener  myFieldChangeListener  =  new  FieldListener()  
  
  
myField.setChangeListener(myFieldChangeListener);