org.millstone.base.data.util
Class HierarchicalContainer

java.lang.Object
  |
  +--org.millstone.base.data.util.IndexedContainer
        |
        +--org.millstone.base.data.util.HierarchicalContainer

All Implemented Interfaces:

Container, Container.Hierarchical, Container.Indexed, Container.ItemSetChangeNotifier, Container.Ordered, Container.PropertySetChangeNotifier, Property.ValueChangeNotifier

public class HierarchicalContainer

extends IndexedContainer

implements Container.Hierarchical

A specialized Container whose contents can be accessed like it was a tree-like structure.

Since:

3.0

Version:

3.0.3

Author:

IT Mill Ltd.

Nested Class Summary

Nested classes inherited from class org.millstone.base.data.Container

Container.Editor, Container.Hierarchical, Container.Indexed, Container.ItemSetChangeEvent, Container.ItemSetChangeListener, Container.ItemSetChangeNotifier, Container.Ordered, Container.PropertySetChangeEvent, Container.PropertySetChangeListener, Container.PropertySetChangeNotifier, Container.Viewer

Field Summary

Fields inherited from interface org.millstone.base.data.Container

NULL_ITEM_ID

Constructor Summary

HierarchicalContainer()

Method Summary

java.lang.Object	addItem() Creates a new Item into the Container, and assign it an automatic ID.
Item	addItem(java.lang.Object itemId) Creates a new Item with the given ID into the Container.
boolean	areChildrenAllowed(java.lang.Object itemId) Tests if the Item with given ID can have any children.
java.util.Collection	getChildren(java.lang.Object itemId) Gets the IDs of all Items that are children of the specified Item.
java.lang.Object	getParent(java.lang.Object itemId) Gets the ID of the parent Item of the specified Item.
boolean	hasChildren(java.lang.Object itemId) Tests if the Item specified with itemId has any child Items, that is, is it a leaf Item.
boolean	isRoot(java.lang.Object itemId) Tests if the Item specified with itemId is a root Item.
boolean	removeAllItems() Removes all Items from the Container.
boolean	removeItem(java.lang.Object itemId) Removes the Item identified by ItemId from the Container.
java.util.Collection	rootItemIds() Gets the IDs of all Items in the container that don't have a parent.
boolean	setChildrenAllowed(java.lang.Object itemId, boolean childrenAllowed) Sets the given Item's capability to have children.
boolean	setParent(java.lang.Object itemId, java.lang.Object newParentId) Sets the parent of an Item.

Methods inherited from class org.millstone.base.data.util.IndexedContainer

addContainerProperty, addItemAfter, addItemAfter, addItemAt, addItemAt, addListener, addListener, addListener, containsId, firstItemId, getContainerProperty, getContainerPropertyIds, getIdByIndex, getItem, getItemIds, getType, indexOfId, isFirstId, isLastId, lastItemId, nextItemId, prevItemId, removeContainerProperty, removeListener, removeListener, removeListener, size

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.millstone.base.data.Container

addContainerProperty, containsId, getContainerProperty, getContainerPropertyIds, getItem, getItemIds, getType, removeContainerProperty, size

Constructor Detail

HierarchicalContainer

public HierarchicalContainer()

Method Detail

areChildrenAllowed

public boolean areChildrenAllowed(java.lang.Object itemId)

Description copied from interface: Container.Hierarchical

Tests if the Item with given ID can have any children. If the Container also implements the Managed interface, the items created with newItem can have children by default.

Specified by:

areChildrenAllowed in interface Container.Hierarchical

Parameters:

itemId - ID of the Item in the container whose child capability is to be tested

Returns:

true if the specified Item exists in the Container and it can have children, false if it's not found from the container or it can't have children.

getChildren

public java.util.Collection getChildren(java.lang.Object itemId)

Description copied from interface: Container.Hierarchical

Gets the IDs of all Items that are children of the specified Item. The returned collection is unmodifiable.

Specified by:

getChildren in interface Container.Hierarchical

Parameters:

itemId - ID of the Item whose children the caller is interested in

Returns:

An unmodifiable collection containing the IDs of all other Items that are children in the container hierarchy

getParent

public java.lang.Object getParent(java.lang.Object itemId)

Description copied from interface: Container.Hierarchical

Gets the ID of the parent Item of the specified Item.

Specified by:

getParent in interface Container.Hierarchical

Parameters:

itemId - ID of the Item whose parent the caller wishes to find out.

Returns:

the ID of the parent Item. Will be null if the specified Item is a root element.

hasChildren

public boolean hasChildren(java.lang.Object itemId)

Description copied from interface: Container.Hierarchical

Tests if the Item specified with itemId has any child Items, that is, is it a leaf Item. The Container.Hierarchical.getChildren(Object itemId) method always returns null for leaf Items.

Note that being a leaf does not imply whether or not an Item is allowed to have children.

.

Specified by:

hasChildren in interface Container.Hierarchical

Parameters:

itemId - ID of the Item whose leaf status is to be tested

Returns:

true if the specified Item is a leaf, false if not

isRoot

public boolean isRoot(java.lang.Object itemId)

Description copied from interface: Container.Hierarchical

Tests if the Item specified with itemId is a root Item. The hierarchical container can have more than one root and must have at least one unless it is empty. The Container.Hierarchical.getParent(Object itemId) method always returns null for root Items.

Specified by:

isRoot in interface Container.Hierarchical

Parameters:

itemId - ID of the Item whose root status is to be tested

Returns:

true if the specified Item is a root, false if not

rootItemIds

public java.util.Collection rootItemIds()

Description copied from interface: Container.Hierarchical

Gets the IDs of all Items in the container that don't have a parent. Such items are called root Items. The returned collection is unmodifiable.

Specified by:

rootItemIds in interface Container.Hierarchical

Returns:

An unmodifiable collection containing IDs of all root elements of the container

setChildrenAllowed

public boolean setChildrenAllowed(java.lang.Object itemId,
                                  boolean childrenAllowed)

Sets the given Item's capability to have children. If the Item identified with itemId already has children and areChildrenAllowed is false this method fails and false is returned; the children must be first explicitly removed with setParent(Object itemId, Object newParentId) or Container.removeItem(Object itemId).

Specified by:

setChildrenAllowed in interface Container.Hierarchical

Parameters:

itemId - ID of the Item in the container whose child capability is to be set

childrenAllowed - boolean value specifying if the Item can have children or not

Returns:

true if the operation succeeded, false if not

setParent

public boolean setParent(java.lang.Object itemId,
                         java.lang.Object newParentId)

Sets the parent of an Item. The new parent item must exist and be able to have children. (canHaveChildren(newParentId) == true). It is also possible to detach a node from the hierarchy (and thus make it root) by setting the parent null.

Specified by:

setParent in interface Container.Hierarchical

Parameters:

itemId - ID of the item to be set as the child of the Item identified with newParentId

newParentId - ID of the Item that's to be the new parent of the Item identified with itemId

Returns:

true if the operation succeeded, false if not

addItem

public java.lang.Object addItem()

Description copied from interface: Container

Creates a new Item into the Container, and assign it an automatic ID.

The new ID is returned, or null if the operation fails. After a successful call you can use the getItem method to fetch the Item.

This functionality is optional.

Specified by:

addItem in interface Container

Overrides:

addItem in class IndexedContainer

Returns:

ID of the newly created Item, or null in case of a failure

See Also:

Container.addItem()

addItem

public Item addItem(java.lang.Object itemId)

Description copied from interface: Container

Creates a new Item with the given ID into the Container. The new

Item is returned, and it is ready to have its Properties modified. Returns null if the operation fails or the Container already contains a Item with the given ID.

This functionality is optional.

Specified by:

addItem in interface Container

Overrides:

addItem in class IndexedContainer

Parameters:

itemId - ID of the Item to be created

Returns:

Created new Item, or null in case of a failure

See Also:

Container.addItem(Object)

removeAllItems

public boolean removeAllItems()

Description copied from interface: Container

Removes all Items from the Container.

Note that Property ID and type information is preserved. This functionality is optional.

Specified by:

removeAllItems in interface Container

Overrides:

removeAllItems in class IndexedContainer

Returns:

true if the operation succeeded, false if not

See Also:

Container.removeAllItems()

removeItem

public boolean removeItem(java.lang.Object itemId)

Description copied from interface: Container

Removes the Item identified by ItemId from the Container. This functionality is optional.

Specified by:

removeItem in interface Container

Overrides:

removeItem in class IndexedContainer

Parameters:

itemId - ID of the Item to remove

Returns:

true if the operation succeeded, false if not

See Also:

Container.removeItem(Object)