org.millstone.base.data.util
Class ContainerHierarchicalWrapper

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

All Implemented Interfaces:

Container, Container.Hierarchical, Container.ItemSetChangeNotifier, Container.PropertySetChangeNotifier

public class ContainerHierarchicalWrapper

extends java.lang.Object

implements Container.Hierarchical, Container.ItemSetChangeNotifier, Container.PropertySetChangeNotifier

A wrapper class for adding external hierarchy to containers not implementing the Container.Hierarchical interface.

If the wrapped container is changed directly (that is, not through the wrapper), the hierarchy information must be updated with the updateHierarchicalWrapper() method.

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

ContainerHierarchicalWrapper(Container toBeWrapped)
Constructs a new hierarchical wrapper for an existing Container.

Method Summary

boolean	addContainerProperty(java.lang.Object propertyId, java.lang.Class type, java.lang.Object defaultValue) Adds a new Property to all Items in the Container.
java.lang.Object	addItem() Creates a new Item into the Container, assigns it an automatic ID, and adds it to the hierarchy.
Item	addItem(java.lang.Object itemId) Adds a new Item by its ID to the underlying container and to the hierarchy.
void	addListener(Container.ItemSetChangeListener listener) Adds a Item set change listener for the object.
void	addListener(Container.PropertySetChangeListener listener) Registers a new Property set change listener for this Container.
boolean	areChildrenAllowed(java.lang.Object itemId) Tests if the Item with given ID can have any children.
boolean	containsId(java.lang.Object itemId) Tests if the Container contains the specified Item
java.util.Collection	getChildren(java.lang.Object itemId) Gets the IDs of all Items that are children of the specified Item.
Property	getContainerProperty(java.lang.Object itemId, java.lang.Object propertyId) Gets the Property identified by the given itemId and propertyId from the Container.
java.util.Collection	getContainerPropertyIds() Gets the ID's of all Properties stored in the Container.
Item	getItem(java.lang.Object itemId) Gets the Item with the given Item ID from the Container.
java.util.Collection	getItemIds() Gets the ID's of all Items stored in the Container.
java.lang.Object	getParent(java.lang.Object itemId) Gets the ID of the parent Item of the specified Item.
java.lang.Class	getType(java.lang.Object propertyId) Gets the data type of all Properties identified by the given Property ID.
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 underlying container and from the hierarcy.
boolean	removeContainerProperty(java.lang.Object propertyId) Removes the specified Property from the underlying container and from the hierarchy.
boolean	removeItem(java.lang.Object itemId) Removes an Item specified by itemId from the underlying container and from the hierarcy.
void	removeListener(Container.ItemSetChangeListener listener) Removes a Item set change listener from the object.
void	removeListener(Container.PropertySetChangeListener listener) Removes a previously registered Property set change listener.
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.
int	size() Gets the number of Items in the Container.
void	updateHierarchicalWrapper() Updates the wrapper's internal hierarchy data to include all Items in the underlying container.

Methods inherited from class java.lang.Object

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

Constructor Detail

ContainerHierarchicalWrapper

public ContainerHierarchicalWrapper(Container toBeWrapped)

Constructs a new hierarchical wrapper for an existing Container. Works even if the to-be-wrapped container already implements the Container.Hierarchical interface.

Parameters:

toBeWrapped - the container that needs to be accessed hierarchically

Method Detail

updateHierarchicalWrapper

public void updateHierarchicalWrapper()

Updates the wrapper's internal hierarchy data to include all Items in the underlying container. If the contents of the wrapped container change without the wrapper's knowledge, this method needs to be called to update the hierarchy information of the Items.

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()
                         throws java.lang.UnsupportedOperationException

Creates a new Item into the Container, assigns it an automatic ID, and adds it to the hierarchy.

Specified by:

addItem in interface Container

Returns:

the autogenerated ID of the new Item or null if the operation failed

java.lang.UnsupportedOperationException

addItem

public Item addItem(java.lang.Object itemId)
             throws java.lang.UnsupportedOperationException

Adds a new Item by its ID to the underlying container and to the hierarchy.

Specified by:

addItem in interface Container

Parameters:

itemId - ID of the Item to be created

Returns:

the added Item or null if the operation failed

java.lang.UnsupportedOperationException

removeAllItems

public boolean removeAllItems()
                       throws java.lang.UnsupportedOperationException

Removes all items from the underlying container and from the hierarcy.

Specified by:

removeAllItems in interface Container

Returns:

true if the operation succeeded, false if not

java.lang.UnsupportedOperationException

removeItem

public boolean removeItem(java.lang.Object itemId)
                   throws java.lang.UnsupportedOperationException

Removes an Item specified by itemId from the underlying container and from the hierarcy.

Specified by:

removeItem in interface Container

Parameters:

itemId - ID of the Item to remove

Returns:

true if the operation succeeded, false if not

java.lang.UnsupportedOperationException

addContainerProperty

public boolean addContainerProperty(java.lang.Object propertyId,
                                    java.lang.Class type,
                                    java.lang.Object defaultValue)
                             throws java.lang.UnsupportedOperationException

Adds a new Property to all Items in the Container.

Specified by:

addContainerProperty in interface Container

Parameters:

propertyId - ID of the new Property

type - Data type of the new Property

defaultValue - The value all created Properties are initialized to

Returns:

true if the operation succeeded, false if not

java.lang.UnsupportedOperationException

removeContainerProperty

public boolean removeContainerProperty(java.lang.Object propertyId)
                                throws java.lang.UnsupportedOperationException

Removes the specified Property from the underlying container and from the hierarchy. Note that the Property will be removed from all Items in the Container.

Specified by:

removeContainerProperty in interface Container

Parameters:

propertyId - ID of the Property to remove

Returns:

true if the operation succeeded, false if not

java.lang.UnsupportedOperationException

containsId

public boolean containsId(java.lang.Object itemId)

Description copied from interface: Container

Tests if the Container contains the specified Item

Specified by:

containsId in interface Container

Parameters:

itemId - ID the of Item to be tested

Returns:

boolean indicating if the Container holds the specified Item

getItem

public Item getItem(java.lang.Object itemId)

Description copied from interface: Container

Gets the Item with the given Item ID from the Container. If the Container does not contain the requested Item, null is returned.

Specified by:

getItem in interface Container

Parameters:

itemId - ID of the Item to retrieve

Returns:

the Item with the given ID or null if the Item is not found in the Container

getItemIds

public java.util.Collection getItemIds()

Description copied from interface: Container

Gets the ID's of all Items stored in the Container. The ID's are returned as a unmodifiable collection.

Specified by:

getItemIds in interface Container

Returns:

unmodifiable collection of Item IDs

getContainerProperty

public Property getContainerProperty(java.lang.Object itemId,
                                     java.lang.Object propertyId)

Description copied from interface: Container

Gets the Property identified by the given itemId and propertyId from the Container. If the Container does not contain the Property, null is returned.

Specified by:

getContainerProperty in interface Container

Parameters:

itemId - ID of the Item which contains the Property

propertyId - ID of the Property to retrieve

Returns:

Property with the given ID or null

getContainerPropertyIds

public java.util.Collection getContainerPropertyIds()

Description copied from interface: Container

Gets the ID's of all Properties stored in the Container. The ID's are returned as a unmodifiable collection.

Specified by:

getContainerPropertyIds in interface Container

Returns:

unmodifiable collection of Property IDs

getType

public java.lang.Class getType(java.lang.Object propertyId)

Description copied from interface: Container

Gets the data type of all Properties identified by the given Property ID.

Specified by:

getType in interface Container

Parameters:

propertyId - ID identifying the Properties

Returns:

data type of the Properties

size

public int size()

Description copied from interface: Container

Gets the number of Items in the Container.

Specified by:

size in interface Container

Returns:

number of Items in the Container

addListener

public void addListener(Container.ItemSetChangeListener listener)

Description copied from interface: Container.ItemSetChangeNotifier

Adds a Item set change listener for the object.

Specified by:

addListener in interface Container.ItemSetChangeNotifier

Parameters:

listener - listener to be added

removeListener

public void removeListener(Container.ItemSetChangeListener listener)

Description copied from interface: Container.ItemSetChangeNotifier

Removes a Item set change listener from the object.

Specified by:

removeListener in interface Container.ItemSetChangeNotifier

Parameters:

listener - listener to be removed

addListener

public void addListener(Container.PropertySetChangeListener listener)

Description copied from interface: Container.PropertySetChangeNotifier

Registers a new Property set change listener for this Container.

Specified by:

addListener in interface Container.PropertySetChangeNotifier

Parameters:

listener - The new Listener to be registered

removeListener

public void removeListener(Container.PropertySetChangeListener listener)

Description copied from interface: Container.PropertySetChangeNotifier

Removes a previously registered Property set change listener.

Specified by:

removeListener in interface Container.PropertySetChangeNotifier

Parameters:

listener - Listener to be removed