/*
* Copyright 2000-2014 Vaadin Ltd.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package com.vaadin.data.util;
import java.util.Collection;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.LinkedList;
import com.vaadin.data.Container;
import com.vaadin.data.Item;
import com.vaadin.data.Property;
/**
* <p>
* A wrapper class for adding external ordering to containers not implementing
* the {@link com.vaadin.data.Container.Ordered} interface.
* </p>
*
* <p>
* If the wrapped container is changed directly (that is, not through the
* wrapper), and does not implement Container.ItemSetChangeNotifier and/or
* Container.PropertySetChangeNotifier the hierarchy information must be updated
* with the {@link #updateOrderWrapper()} method.
* </p>
*
* @author Vaadin Ltd.
* @since 3.0
*/
@SuppressWarnings("serial")
public class ContainerOrderedWrapper implements Container.Ordered,
Container.ItemSetChangeNotifier, Container.PropertySetChangeNotifier {
/**
* The wrapped container
*/
private final Container container;
/**
* Ordering information, ie. the mapping from Item ID to the next item ID
*/
private Hashtable<Object, Object> next;
/**
* Reverse ordering information for convenience and performance reasons.
*/
private Hashtable<Object, Object> prev;
/**
* ID of the first Item in the container.
*/
private Object first;
/**
* ID of the last Item in the container.
*/
private Object last;
/**
* Is the wrapped container ordered by itself, ie. does it implement the
* Container.Ordered interface by itself? If it does, this class will use
* the methods of the underlying container directly.
*/
private boolean ordered = false;
/**
* The last known size of the wrapped container. Used to check whether items
* have been added or removed to the wrapped container, when the wrapped
* container does not send ItemSetChangeEvents.
*/
private int lastKnownSize = -1;
/**
* Constructs a new ordered wrapper for an existing Container. Works even if
* the to-be-wrapped container already implements the Container.Ordered
* interface.
*
* @param toBeWrapped
* the container whose contents need to be ordered.
*/
public ContainerOrderedWrapper(Container toBeWrapped) {
container = toBeWrapped;
ordered = container instanceof Container.Ordered;
// Checks arguments
if (container == null) {
throw new NullPointerException("Null can not be wrapped");
}
// Creates initial order if needed
updateOrderWrapper();
}
/**
* Removes the specified Item from the wrapper's internal hierarchy
* structure.
* <p>
* Note : The Item is not removed from the underlying Container.
* </p>
*
* @param id
* the ID of the Item to be removed from the ordering.
*/
private void removeFromOrderWrapper(Object id) {
if (id != null) {
final Object pid = prev.get(id);
final Object nid = next.get(id);
if (first.equals(id)) {
first = nid;
}
if (last.equals(id)) {
first = pid;
}
if (nid != null) {
prev.put(nid, pid);
}
if (pid != null) {
next.put(pid, nid);
}
next.remove(id);
prev.remove(id);
}
}
/**
* Registers the specified Item to the last position in the wrapper's
* internal ordering. The underlying container is not modified.
*
* @param id
* the ID of the Item to be added to the ordering.
*/
private void addToOrderWrapper(Object id) {
// Adds the if to tail
if (last != null) {
next.put(last, id);
prev.put(id, last);
last = id;
} else {
first = last = id;
}
}
/**
* Registers the specified Item after the specified itemId in the wrapper's
* internal ordering. The underlying container is not modified. Given item
* id must be in the container, or must be null.
*
* @param id
* the ID of the Item to be added to the ordering.
* @param previousItemId
* the Id of the previous item.
*/
private void addToOrderWrapper(Object id, Object previousItemId) {
if (last == previousItemId || last == null) {
addToOrderWrapper(id);
} else {
if (previousItemId == null) {
next.put(id, first);
prev.put(first, id);
first = id;
} else {
prev.put(id, previousItemId);
next.put(id, next.get(previousItemId));
prev.put(next.get(previousItemId), id);
next.put(previousItemId, id);
}
}
}
/**
* Updates the wrapper's internal ordering information to include all Items
* in the underlying container.
* <p>
* Note : If the contents of the wrapped container change without the
* wrapper's knowledge, this method needs to be called to update the
* ordering information of the Items.
* </p>
*/
public void updateOrderWrapper() {
if (!ordered) {
final Collection<?> ids = container.getItemIds();
// Recreates ordering if some parts of it are missing
if (next == null || first == null || last == null || prev != null) {
first = null;
last = null;
next = new Hashtable<Object, Object>();
prev = new Hashtable<Object, Object>();
}
// Filter out all the missing items
final LinkedList<?> l = new LinkedList<Object>(next.keySet());
for (final Iterator<?> i = l.iterator(); i.hasNext();) {
final Object id = i.next();
if (!container.containsId(id)) {
removeFromOrderWrapper(id);
}
}
// Adds missing items
for (final Iterator<?> i = ids.iterator(); i.hasNext();) {
final Object id = i.next();
if (!next.containsKey(id)) {
addToOrderWrapper(id);
}
}
}
}
/*
* Gets the first item stored in the ordered container Don't add a JavaDoc
* comment here, we use the default documentation from implemented
* interface.
*/
@Override
public Object firstItemId() {
if (ordered) {
return ((Container.Ordered) container).firstItemId();
}
return first;
}
/*
* Tests if the given item is the first item in the container Don't add a
* JavaDoc comment here, we use the default documentation from implemented
* interface.
*/
@Override
public boolean isFirstId(Object itemId) {
if (ordered) {
return ((Container.Ordered) container).isFirstId(itemId);
}
return first != null && first.equals(itemId);
}
/*
* Tests if the given item is the last item in the container Don't add a
* JavaDoc comment here, we use the default documentation from implemented
* interface.
*/
@Override
public boolean isLastId(Object itemId) {
if (ordered) {
return ((Container.Ordered) container).isLastId(itemId);
}
return last != null && last.equals(itemId);
}
/*
* Gets the last item stored in the ordered container Don't add a JavaDoc
* comment here, we use the default documentation from implemented
* interface.
*/
@Override
public Object lastItemId() {
if (ordered) {
return ((Container.Ordered) container).lastItemId();
}
return last;
}
/*
* Gets the item that is next from the specified item. Don't add a JavaDoc
* comment here, we use the default documentation from implemented
* interface.
*/
@Override
public Object nextItemId(Object itemId) {
if (ordered) {
return ((Container.Ordered) container).nextItemId(itemId);
}
if (itemId == null) {
return null;
}
return next.get(itemId);
}
/*
* Gets the item that is previous from the specified item. Don't add a
* JavaDoc comment here, we use the default documentation from implemented
* interface.
*/
@Override
public Object prevItemId(Object itemId) {
if (ordered) {
return ((Container.Ordered) container).prevItemId(itemId);
}
if (itemId == null) {
return null;
}
return prev.get(itemId);
}
/**
* Registers a new Property to all Items in the Container.
*
* @param propertyId
* the ID of the new Property.
* @param type
* the Data type of the new Property.
* @param defaultValue
* the value all created Properties are initialized to.
* @return <code>true</code> if the operation succeeded, <code>false</code>
* if not
*/
@Override
public boolean addContainerProperty(Object propertyId, Class<?> type,
Object defaultValue) throws UnsupportedOperationException {
return container.addContainerProperty(propertyId, type, defaultValue);
}
/**
* Creates a new Item into the Container, assigns it an automatic ID, and
* adds it to the ordering.
*
* @return the autogenerated ID of the new Item or <code>null</code> if the
* operation failed
* @throws UnsupportedOperationException
* if the addItem is not supported.
*/
@Override
public Object addItem() throws UnsupportedOperationException {
final Object id = container.addItem();
if (!ordered && id != null) {
addToOrderWrapper(id);
}
return id;
}
/**
* Registers a new Item by its ID to the underlying container and to the
* ordering.
*
* @param itemId
* the ID of the Item to be created.
* @return the added Item or <code>null</code> if the operation failed
* @throws UnsupportedOperationException
* if the addItem is not supported.
*/
@Override
public Item addItem(Object itemId) throws UnsupportedOperationException {
final Item item = container.addItem(itemId);
if (!ordered && item != null) {
addToOrderWrapper(itemId);
}
return item;
}
/**
* Removes all items from the underlying container and from the ordering.
*
* @return <code>true</code> if the operation succeeded, otherwise
* <code>false</code>
* @throws UnsupportedOperationException
* if the removeAllItems is not supported.
*/
@Override
public boolean removeAllItems() throws UnsupportedOperationException {
final boolean success = container.removeAllItems();
if (!ordered && success) {
first = last = null;
next.clear();
prev.clear();
}
return success;
}
/**
* Removes an Item specified by the itemId from the underlying container and
* from the ordering.
*
* @param itemId
* the ID of the Item to be removed.
* @return <code>true</code> if the operation succeeded, <code>false</code>
* if not
* @throws UnsupportedOperationException
* if the removeItem is not supported.
*/
@Override
public boolean removeItem(Object itemId)
throws UnsupportedOperationException {
final boolean success = container.removeItem(itemId);
if (!ordered && success) {
removeFromOrderWrapper(itemId);
}
return success;
}
/**
* Removes the specified Property from the underlying container and from the
* ordering.
* <p>
* Note : The Property will be removed from all the Items in the Container.
* </p>
*
* @param propertyId
* the ID of the Property to remove.
* @return <code>true</code> if the operation succeeded, <code>false</code>
* if not
* @throws UnsupportedOperationException
* if the removeContainerProperty is not supported.
*/
@Override
public boolean removeContainerProperty(Object propertyId)
throws UnsupportedOperationException {
return container.removeContainerProperty(propertyId);
}
/*
* Does the container contain the specified Item? Don't add a JavaDoc
* comment here, we use the default documentation from implemented
* interface.
*/
@Override
public boolean containsId(Object itemId) {
return container.containsId(itemId);
}
/*
* Gets the specified Item from the container. Don't add a JavaDoc comment
* here, we use the default documentation from implemented interface.
*/
@Override
public Item getItem(Object itemId) {
return container.getItem(itemId);
}
/*
* Gets the ID's of all Items stored in the Container Don't add a JavaDoc
* comment here, we use the default documentation from implemented
* interface.
*/
@Override
public Collection<?> getItemIds() {
return container.getItemIds();
}
/*
* Gets the Property identified by the given itemId and propertyId from the
* Container Don't add a JavaDoc comment here, we use the default
* documentation from implemented interface.
*/
@Override
public Property getContainerProperty(Object itemId, Object propertyId) {
return container.getContainerProperty(itemId, propertyId);
}
/*
* Gets the ID's of all Properties stored in the Container Don't add a
* JavaDoc comment here, we use the default documentation from implemented
* interface.
*/
@Override
public Collection<?> getContainerPropertyIds() {
return container.getContainerPropertyIds();
}
/*
* Gets the data type of all Properties identified by the given Property ID.
* Don't add a JavaDoc comment here, we use the default documentation from
* implemented interface.
*/
@Override
public Class<?> getType(Object propertyId) {
return container.getType(propertyId);
}
/*
* Gets the number of Items in the Container. Don't add a JavaDoc comment
* here, we use the default documentation from implemented interface.
*/
@Override
public int size() {
int newSize = container.size();
assert newSize >= 0;
if (lastKnownSize != -1 && newSize != lastKnownSize
&& !(container instanceof Container.ItemSetChangeNotifier)) {
// Update the internal cache when the size of the container changes
// and the container is incapable of sending ItemSetChangeEvents
updateOrderWrapper();
}
lastKnownSize = newSize;
return newSize;
}
/*
* Registers a new Item set change listener for this Container. Don't add a
* JavaDoc comment here, we use the default documentation from implemented
* interface.
*/
@Override
public void addItemSetChangeListener(
Container.ItemSetChangeListener listener) {
if (container instanceof Container.ItemSetChangeNotifier) {
((Container.ItemSetChangeNotifier) container)
.addItemSetChangeListener(new PiggybackListener(listener));
}
}
/**
* @deprecated As of 7.0, replaced by
* {@link #addItemSetChangeListener(com.vaadin.data.Container.ItemSetChangeListener)}
**/
@Override
@Deprecated
public void addListener(Container.ItemSetChangeListener listener) {
addItemSetChangeListener(listener);
}
/*
* Removes a Item set change listener from the object. Don't add a JavaDoc
* comment here, we use the default documentation from implemented
* interface.
*/
@Override
public void removeItemSetChangeListener(
Container.ItemSetChangeListener listener) {
if (container instanceof Container.ItemSetChangeNotifier) {
((Container.ItemSetChangeNotifier) container)
.removeItemSetChangeListener(new PiggybackListener(listener));
}
}
/**
* @deprecated As of 7.0, replaced by
* {@link #removeItemSetChangeListener(com.vaadin.data.Container.ItemSetChangeListener)}
**/
@Override
@Deprecated
public void removeListener(Container.ItemSetChangeListener listener) {
removeItemSetChangeListener(listener);
}
/*
* Registers a new Property set change listener for this Container. Don't
* add a JavaDoc comment here, we use the default documentation from
* implemented interface.
*/
@Override
public void addPropertySetChangeListener(
Container.PropertySetChangeListener listener) {
if (container instanceof Container.PropertySetChangeNotifier) {
((Container.PropertySetChangeNotifier) container)
.addPropertySetChangeListener(new PiggybackListener(
listener));
}
}
/**
* @deprecated As of 7.0, replaced by
* {@link #addPropertySetChangeListener(com.vaadin.data.Container.PropertySetChangeListener)}
**/
@Override
@Deprecated
public void addListener(Container.PropertySetChangeListener listener) {
addPropertySetChangeListener(listener);
}
/*
* Removes a Property set change listener from the object. Don't add a
* JavaDoc comment here, we use the default documentation from implemented
* interface.
*/
@Override
public void removePropertySetChangeListener(
Container.PropertySetChangeListener listener) {
if (container instanceof Container.PropertySetChangeNotifier) {
((Container.PropertySetChangeNotifier) container)
.removePropertySetChangeListener(new PiggybackListener(
listener));
}
}
/**
* @deprecated As of 7.0, replaced by
* {@link #removePropertySetChangeListener(com.vaadin.data.Container.PropertySetChangeListener)}
**/
@Override
@Deprecated
public void removeListener(Container.PropertySetChangeListener listener) {
removePropertySetChangeListener(listener);
}
/*
* (non-Javadoc)
*
* @see com.vaadin.data.Container.Ordered#addItemAfter(java.lang.Object,
* java.lang.Object)
*/
@Override
public Item addItemAfter(Object previousItemId, Object newItemId)
throws UnsupportedOperationException {
// If the previous item is not in the container, fail
if (previousItemId != null && !containsId(previousItemId)) {
return null;
}
// Adds the item to container
final Item item = container.addItem(newItemId);
// Puts the new item to its correct place
if (!ordered && item != null) {
addToOrderWrapper(newItemId, previousItemId);
}
return item;
}
/*
* (non-Javadoc)
*
* @see com.vaadin.data.Container.Ordered#addItemAfter(java.lang.Object)
*/
@Override
public Object addItemAfter(Object previousItemId)
throws UnsupportedOperationException {
// If the previous item is not in the container, fail
if (previousItemId != null && !containsId(previousItemId)) {
return null;
}
// Adds the item to container
final Object id = container.addItem();
// Puts the new item to its correct place
if (!ordered && id != null) {
addToOrderWrapper(id, previousItemId);
}
return id;
}
/**
* This listener 'piggybacks' on the real listener in order to update the
* wrapper when needed. It proxies equals() and hashCode() to the real
* listener so that the correct listener gets removed.
*
*/
private class PiggybackListener implements
Container.PropertySetChangeListener,
Container.ItemSetChangeListener {
Object listener;
public PiggybackListener(Object realListener) {
listener = realListener;
}
@Override
public void containerItemSetChange(ItemSetChangeEvent event) {
updateOrderWrapper();
((Container.ItemSetChangeListener) listener)
.containerItemSetChange(event);
}
@Override
public void containerPropertySetChange(PropertySetChangeEvent event) {
updateOrderWrapper();
((Container.PropertySetChangeListener) listener)
.containerPropertySetChange(event);
}
@Override
public boolean equals(Object obj) {
return obj == listener || (obj != null && obj.equals(listener));
}
@Override
public int hashCode() {
return listener.hashCode();
}
}
}