IContributionRoot (Eclipse Platform API Specification)

```
public interface IContributionRoot
```
Instances of this interface represent a position in the contribution hierarchy into which AbstractContributionFactory instances may insert elements. Instances of this interface are provided by the platform and this interface should NOT be implemented by clients.

Since:

3.3

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`addContributionItem(IContributionItem item, Expression visibleWhen)`	Adds a given contribution item with provided visibility expression and kill-switch filtering as a direct child of this container.
`void`	`registerVisibilityForChild(IContributionItem item, Expression visibleWhen)`	Registers visibilty for arbitrary `IContributionItem` instances that are NOT direct children of this container.

- Method Detail
  - addContributionItem
```
void addContributionItem(IContributionItem item,
                         Expression visibleWhen)
```
    Adds a given contribution item with provided visibility expression and kill-switch filtering as a direct child of this container. This should be called for all top-level elements created in AbstractContributionFactory.createContributionItems(org.eclipse.ui.services.IServiceLocator, IContributionRoot)
    
    Parameters:
    
    item - the item to add
    
    visibleWhen - the visibility expression. May be null.
  - registerVisibilityForChild
```
void registerVisibilityForChild(IContributionItem item,
                                Expression visibleWhen)
```
    Registers visibilty for arbitrary IContributionItem instances that are NOT direct children of this container. Ie: children of a IContributionManager that has been previously registered with a call to {addContributionItem(IContributionItem, Expression).
    
    Parameters:
    
    item - the item for which to register a visibility clause
    
    visibleWhen - the visibility expression. May be null in which case this method is a no-op.