Property Change Listener for an Array

[scottie_uk]

Is it possible in any way to add an event listener to listen for changes made to an array of Strings.

I have a private array of strings in one class, I wish its parent calling class to know when any values in this array list have been changed??


Any usefull Ideas??

[sjalle]

You could isolate all updates to the array in a method, and implement a
special method in the other class like:

// constructor

public class SomeClass {
  private OtherClass otherClass=null;

  public SomeClass(OtherClass otherClass) {
    this otherClass=otherClass;
  }
int [] array;
.
.
.
.
private void setValue(int val, int pos) {
  array[pos]=val; 
  otherClass.listenMethod(int val, int pos);
}

Or you could isolate the array inside a class and supply it with a listener
interface:

interface ArrayListener {
  public void valueChanged(int newVal, int oldVal, int pos);
}

public class BCArray {
  public int [] array=null;
  ArrayListener arrayListener=null;

  public BCArray(int [] array) {
    this.array=array;
  }
  public void setArrayListener (ArrayListener arrayListener) {
    this.arrayListener=arrayListener;
  }
  public void setValue(int val, int pos) {
    int oldVal=array[pos];
    array[pos]=val;
    arrayListener.valueChanged(val,oldVal,pos);
  }
}

Either way, the class that changes the array must have a pointer to the
other class, either as an interface or as a plain instance reference.

[scottie_uk]

Thanks I'l have a bash at it!!