IChangingListener (LWT 5.3.100-SNAPSHOT API)

Type Parameters:

S - the changing event source.

V - the type of the value changing.
```
public interface IChangingListener<S,V>
```
Pre-change listener contract.

- Method Summary
  
  All Methods Instance Methods Abstract Methods
  Modifier and Type Method Description
  
  boolean changing(S source, V value)
  Invoked when some source value is about to change.

- Method Detail
  - changing
```
boolean changing(S source,
                 V value)
```
    Invoked when some source value is about to change.
    
    Parameters:
    
    source - the value source.
    
    value - the new value.
    
    Returns:
    
    true to allow the change, false to block the change.