TraversalListener (vmf-runtime API)

```
public interface TraversalListener
```
Traversal listener for traversing object graphs and performing corresponding actions.
Created by miho on 10.03.2017.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`default boolean`	`isIgnoreNullObjects()`	Indicates whether `null` objects are ignored.
`void`	`onEnter(VObject o)`	Called whenever the traversal algorithm enters an object node.
`void`	`onExit(VObject o)`	Called whenever the traversal algorithm exits an object node.
`static void`	`traverse(VObject o, TraversalListener tl)`	Traverses the specified object graph with the default strategy.
`static void`	`traverse(VObject o, TraversalListener tl, VIterator.IterationStrategy strategy)`	Traverses the specified object graph.

- Method Detail
  - onEnter
```
void onEnter(VObject o)
```
    Called whenever the traversal algorithm enters an object node.
    
    Parameters:
    
    o - object node
  - onExit
```
void onExit(VObject o)
```
    Called whenever the traversal algorithm exits an object node.
    
    Parameters:
    
    o - object node
  - isIgnoreNullObjects
```
default boolean isIgnoreNullObjects()
```
    Indicates whether null objects are ignored.
    
    Returns:
    
    true if null objects are ignored; false otherwise
  - traverse
```
static void traverse(VObject o,
                     TraversalListener tl)
```
    Traverses the specified object graph with the default strategy.
    
    Parameters:
    
    o - object graph to be traversed
    
    tl - traversal listener
    
    See Also:
    
    VIterator.IterationStrategy
  - traverse
```
static void traverse(VObject o,
                     TraversalListener tl,
                     VIterator.IterationStrategy strategy)
```
    Traverses the specified object graph.
    
    Parameters:
    
    o - object graph to be traversed
    
    tl - traversal listener
    
    strategy - iteration strategy