ContextListener

```
public interface ContextListener
```
The context graph mutation listener interface.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`graphAdded(TreeNode parent, TreeNode added)`	Called when a new subgraph is attached.
`void`	`graphRemoved(TreeNode parent, TreeNode removed)`	Called when a subgraph is detached.

- Method Detail
  - graphAdded
```
void graphAdded(TreeNode parent,
                TreeNode added)
```
    Called when a new subgraph is attached.
    The parent node is the currently attached node to which the incoming graph has been attached. The added node is the newly attached sub-graph. The graph accessible beneath added may include sub-graphs that are already attached to this tree.
    
    Parameters:
    
    parent - parent of the new sub-graph
    
    added - newly added sub-graph
  - graphRemoved
```
void graphRemoved(TreeNode parent,
                  TreeNode removed)
```
    Called when a subgraph is detached.
    The parent node the still attached node from which the outgoing graph has been detached. The removed node is the just detached sub-graph. The graph accessible beneath removed may include sub-graphs that are still attached to this tree.
    
    Parameters:
    
    parent - previous parent of the removed sub-graph
    
    removed - the removed sub-graph