com.helger.commons.hierarchy

Interface IChildrenProvider<CHILDTYPE>

Type Parameters:

CHILDTYPE - The type of the children to retrieve.

All Known Subinterfaces:

IChildrenProviderSorted<CHILDTYPE>, IChildrenProviderWithID<KEYTYPE,CHILDTYPE>

All Known Implementing Classes:

ChildrenProviderHasChildren, ChildrenProviderHasChildrenSorted, ChildrenProviderHasChildrenSorting, ChildrenProviderHasChildrenWithID, ChildrenProviderSorting, ChildrenProviderSortingWithID

public interface IChildrenProvider<CHILDTYPE>

This interface can be used to generically resolved children of a certain object.

Author:

Philip Helger

Method Summary

Modifier and Type	Method and Description
ICommonsCollection<? extends CHILDTYPE>	getAllChildren(CHILDTYPE aCurrent) Get the children of the passed object.
int	getChildCount(CHILDTYPE aCurrent)
default boolean	hasChildren(CHILDTYPE aCurrent) Check if an item has children.
default boolean	hasNoChildren(CHILDTYPE aCurrent) Check if an item has no children.

Method Detail

hasChildren

default boolean hasChildren(CHILDTYPE aCurrent)

Check if an item has children.

Parameters:

aCurrent - The object to determine the children of. No null or non- null constraint possible.

Returns:

true if this item has children, false otherwise.

hasNoChildren

default boolean hasNoChildren(CHILDTYPE aCurrent)

Check if an item has no children.

Parameters:

aCurrent - The object to determine the children of. No null or non- null constraint possible.

Returns:

true if this item has no children, false otherwise.

getChildCount

@Nonnegative
int getChildCount(CHILDTYPE aCurrent)

Parameters:

aCurrent - The object to determine the children count of. No null or non- null constraint possible.

Returns:

The number of contained direct children. Always ≥ 0.

getAllChildren

@Nullable
ICommonsCollection<? extends CHILDTYPE> getAllChildren(CHILDTYPE aCurrent)

Get the children of the passed object.

Parameters:

aCurrent - The object to determine the children of. No null or non-null constraint possible.

Returns:

The child objects, or null if there are no children. If null is passed, the resolver is expected to return any possible top level (root) elements. This method may NOT return null if the call to hasChildren(Object) with the same object returned true.