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Event-driven lists for dynamically filtered and sorted tables
/* Glazed Lists (c) 2003-2006 */
/* http://publicobject.com/glazedlists/ publicobject.com,*/
/* O'Dell Engineering Ltd.*/
package ca.odell.glazedlists;
import ca.odell.glazedlists.event.ListEvent;
import ca.odell.glazedlists.event.ListEventListener;
import ca.odell.glazedlists.impl.adt.Barcode;
import ca.odell.glazedlists.impl.adt.barcode2.Element;
import ca.odell.glazedlists.impl.adt.barcode2.SimpleTree;
import ca.odell.glazedlists.impl.adt.barcode2.SimpleTreeIterator;
import java.util.Collections;
import java.util.List;
/**
* A list that acts like a tree in that it contains child elements to nodes
* contained in another list. An example usage would be to wrap a parent list
* containing albums and use the CollectionList to display the songs on the
* album.
*
* The actual mapping from the parent list to the child list (album to
* songs in the above example) is done by a {@link CollectionList.Model} that
* is provided to the constructor.
*
*
Note that any {@link EventList}s returned by the {@link CollectionList.Model}
* must use the same {@link ca.odell.glazedlists.event.ListEventPublisher} and
* {@link ca.odell.glazedlists.util.concurrent.ReadWriteLock} as this
* {@link CollectionList}. This is necessary in order for CollectionList to
* operate correctly under mult-threaded conditions. An
* {@link IllegalArgumentException} will be raised if this invariant is violated.
*
*
Warning: This class is
* thread ready but not thread safe. See {@link EventList} for an example
* of thread safe code.
*
*
* EventList Overview Writable: only {@link #set(int,Object)} and {@link #remove(int)} Concurrency: thread ready, not thread safe Performance: reads: O(log N), writes O(log N) Memory: 96 bytes per element Unit Tests: N/A Issues:
* 96
* 162
* 257
* 265
*
*
* @see CollectionList.Model
*
* @author Rob Eden
* @author Jesse Wilson
*/
public class CollectionList extends TransformedList implements ListEventListener {
/** This is a hack - we need a temporary value when inserting into IndexedTrees, and this is the one we use. */
private final ChildElement EMPTY_CHILD_ELEMENT = new SimpleChildElement(Collections.EMPTY_LIST, null);
/** used to extract children */
private final Model model;
/**
* Barcode containing the node mappings. There is a black node for each parent
* followed by a white node for each of its children.
*/
private final Barcode barcode = new Barcode();
/** the Lists and EventLists that this is composed of */
private final SimpleTree> childElements = new SimpleTree>();
/**
* Create a {@link CollectionList} with its contents being the children of
* the elements in the specified source {@link EventList}.
*
* @param source an EventList of Objects from each of which the
* model can extract child elements
* @param model the logic for extracting children from each
* source element
*/
public CollectionList(EventList source, Model model) {
super(source);
if(model == null) throw new IllegalArgumentException("model cannot be null");
this.model = model;
// sync the current size and indexes
for(int i = 0, n = source.size(); i < n; i++) {
List children = model.getChildren(source.get(i));
// update the list of child lists
Element> node = childElements.add(i, EMPTY_CHILD_ELEMENT, 1);
node.set(createChildElementForList(children, node));
// update the barcode
barcode.addBlack(barcode.size(), 1);
if(!children.isEmpty()) barcode.addWhite(barcode.size(), children.size());
}
// listen for changes
source.addListEventListener(this);
}
/**
* @return false because we cannot support {@link #add(int, Object)};
* though we do support {@link #set(int, Object)} and {@link #remove(int)}
*/
protected boolean isWritable() {
return false;
}
/** {@inheritDoc} */
public int size() {
// size of the child nodes only
return barcode.whiteSize();
}
/** {@inheritDoc} */
public E get(int index) {
// get the child
final ChildElement childElement = getChildElement(index);
final int childIndexInParent = barcode.getWhiteSequenceIndex(index);
return childElement.get(childIndexInParent);
}
/** {@inheritDoc} */
public E set(int index, E value) {
// set on the child
final ChildElement childElement = getChildElement(index);
final int childIndexInParent = barcode.getWhiteSequenceIndex(index);
return childElement.set(childIndexInParent, value);
}
/** {@inheritDoc} */
public E remove(int index) {
// remove from the child
final ChildElement childElement = getChildElement(index);
final int childIndexInParent = barcode.getWhiteSequenceIndex(index);
return childElement.remove(childIndexInParent);
}
/**
* Return the index of the first child in the CollectionList for the given
* parent index. This can be very useful for things like selecting the
* children in a CollectionList when the parent is selected in another list.
*
* @see #childEndingIndex
*/
public int childStartingIndex(int parentIndex) {
if(parentIndex < 0) throw new IndexOutOfBoundsException("Invalid index: " + parentIndex);
if(parentIndex >= source.size()) throw new IndexOutOfBoundsException("Invalid index: " + parentIndex);
// get the index of the next node
// find the index of the black node with that index
final int parentFullIndex = barcode.getIndex(parentIndex, Barcode.BLACK);
final int childFullIndex = parentFullIndex + 1;
// ff this node has no children, the next node index will be past the size or black
if(childFullIndex >= barcode.size()) return -1;
if(barcode.get(childFullIndex) != Barcode.WHITE) return -1;
// return the child index
final int childIndex = childFullIndex - (parentIndex+1);
assert(barcode.getWhiteIndex(childFullIndex) == childIndex);
return childIndex;
}
/**
* Return the index of the last child in the CollectionList for the given
* parent index. This can be very useful for things like selecting the
* children in a CollectionList when the parent is selected in another list.
*
* @see #childStartingIndex
*/
public int childEndingIndex(int parentIndex) {
if(parentIndex < 0) throw new IndexOutOfBoundsException("Invalid index: " + parentIndex);
if(parentIndex >= source.size()) throw new IndexOutOfBoundsException("Invalid index: " + parentIndex);
// Get the index of the next node
// Find the index of the black node with that index
final int nextParentFullIndex = (parentIndex == barcode.blackSize() - 1) ? barcode.size() : barcode.getIndex(parentIndex + 1, Barcode.BLACK);
final int lastWhiteBeforeNextParent = nextParentFullIndex - 1;
// If this node has no children, the next node index will be past the size or black
if(barcode.get(lastWhiteBeforeNextParent) == Barcode.BLACK) return -1;
// return the child index
final int childIndex = lastWhiteBeforeNextParent - (parentIndex+1);
assert(barcode.getWhiteIndex(lastWhiteBeforeNextParent) == childIndex);
return childIndex;
}
/**
* Handle changes in the parent list. We'll need to update our node list
* sizes.
*/
public void listChanged(ListEvent listChanges) {
// need to process the changes so that our size caches are up to date.
updates.beginEvent();
while(listChanges.next()) {
int index = listChanges.getIndex();
int type = listChanges.getType();
// insert means we'll need to insert a new node in the array
if(type == ListEvent.INSERT) {
handleInsert(index);
} else if(type == ListEvent.DELETE) {
handleDelete(index);
// treat like a delete and then an add:
} else if(type == ListEvent.UPDATE) {
handleDelete(index);
handleInsert(index);
}
}
updates.commitEvent();
}
/** @inheritDoc */
public void dispose() {
super.dispose();
// iterate over all child elements and dispose them
final SimpleTreeIterator> treeIterator = new SimpleTreeIterator>(childElements);
while(treeIterator.hasNext()) {
treeIterator.next();
treeIterator.value().dispose();
}
}
/**
* Helper for {@link #listChanged(ListEvent)} when inserting.
*/
private void handleInsert(int parentIndex) {
// find the index of the black node with that index
int absoluteIndex = getAbsoluteIndex(parentIndex);
// find the size of the new node and add it to the total
S parent = source.get(parentIndex);
List children = model.getChildren(parent);
// update the list of child lists
Element> node = childElements.add(parentIndex, EMPTY_CHILD_ELEMENT, 1);
node.set(createChildElementForList(children, node));
// update the barcode
barcode.addBlack(absoluteIndex, 1);
if(!children.isEmpty()) barcode.addWhite(absoluteIndex + 1, children.size());
// add events
int childIndex = absoluteIndex - parentIndex;
for(int i = 0; i < children.size(); i++) {
E element = children.get(i);
updates.elementInserted(childIndex, element);
}
}
/**
* Helper for {@link #listChanged(ListEvent)} when deleting.
*/
private void handleDelete(int sourceIndex) {
// find the index of the black node with that index
final int parentIndex = getAbsoluteIndex(sourceIndex);
final int nextParentIndex = getAbsoluteIndex(sourceIndex + 1);
final int childCount = nextParentIndex - parentIndex - 1; // subtract one for the parent
// record the delete events first while the deleted values still exist
if(childCount > 0) {
int firstDeletedChildIndex = parentIndex - sourceIndex;
int firstNotDeletedChildIndex = firstDeletedChildIndex + childCount;
for (int i = firstDeletedChildIndex; i < firstNotDeletedChildIndex; i++) {
updates.elementDeleted(firstDeletedChildIndex, get(i));
}
}
// update the list of child lists
Element> removedChildElement = childElements.get(sourceIndex);
childElements.remove(removedChildElement);
removedChildElement.get().dispose();
// update the barcode
barcode.remove(parentIndex, 1 + childCount); // delete the parent and all children
}
/**
* Get the child element for the specified child index.
*/
private ChildElement getChildElement(int childIndex) {
if(childIndex < 0) throw new IndexOutOfBoundsException("Invalid index: " + childIndex);
if(childIndex >= size()) throw new IndexOutOfBoundsException("Index: " + childIndex + ", Size: " + size());
// get the child element
int parentIndex = barcode.getBlackBeforeWhite(childIndex);
return childElements.get(parentIndex).get();
}
/**
* Create a {@link ChildElement} for the specified List.
*/
private ChildElement createChildElementForList(List children, Element> node) {
if(children instanceof EventList)
return new EventChildElement((EventList) children, node);
else
return new SimpleChildElement(children, node);
}
/**
* Get the absolute index for the specified parent index. This may be
* virtual if the parent index is one greater than the last element. This
* is useful for calculating the size of a range by using the location of
* its follower.
*/
private int getAbsoluteIndex(int parentIndex) {
if(parentIndex < barcode.blackSize())
return barcode.getIndex(parentIndex, Barcode.BLACK);
if(parentIndex == barcode.blackSize())
return barcode.size();
throw new IndexOutOfBoundsException();
}
/**
* Models a list held by the CollectionList.
*/
private interface ChildElement {
public E get(int index);
public E remove(int index);
public E set(int index, E element);
public void dispose();
}
/**
* Provides the logic to map a parent object (e.g. an album) to its
* children (e.g. the songs on the album). Serves basically the same
* purpose as {@link javax.swing.tree.TreeModel} does to a JTree in Swing.
*
* @see CollectionList
* @see GlazedLists#listCollectionListModel()
*/
public interface Model {
/**
* Return a list of the child nodes for a parent node.
*
* @param parent the parent node.
* @return a List containing the child nodes.
*/
public List getChildren(E parent);
}
/**
* Manages a standard List that does not implement {@link EventList}.
*/
private class SimpleChildElement implements ChildElement {
private final List children;
private final Element> node;
public SimpleChildElement(List children, Element> node) {
this.children = children;
this.node = node;
}
public E get(int index) {
return children.get(index);
}
public E remove(int index) {
E removed = children.remove(index);
// update the barcode
int parentIndex = childElements.indexOfNode(node, (byte)0);
int absoluteIndex = getAbsoluteIndex(parentIndex);
int firstChildIndex = absoluteIndex + 1;
barcode.remove(firstChildIndex + index, 1);
// forward the offset event
int childOffset = absoluteIndex - parentIndex;
updates.beginEvent();
updates.elementDeleted(index + childOffset, removed);
updates.commitEvent();
// all done
return removed;
}
public E set(int index, E element) {
E replaced = children.set(index, element);
// forward the offset event
int parentIndex = childElements.indexOfNode(node, (byte)0);
int absoluteIndex = getAbsoluteIndex(parentIndex);
int childOffset = absoluteIndex - parentIndex;
updates.beginEvent();
updates.elementUpdated(index + childOffset, replaced);
updates.commitEvent();
// all done
return replaced;
}
public void dispose() {
// do nothing
}
}
/**
* Monitors changes to a member EventList and forwards changes to all
* listeners of the CollectionList.
*/
private class EventChildElement implements ChildElement, ListEventListener {
private final EventList children;
private final Element> node;
public EventChildElement(EventList children, Element> node) {
this.children = children;
this.node = node;
// ensure the EventList of children uses the same publisher as the CollectionList
if(!getPublisher().equals(children.getPublisher()))
throw new IllegalArgumentException("If a CollectionList.Model returns EventLists, those EventLists must use the same ListEventPublisher as the CollectionList");
// ensure the EventList of children uses the same locks as the CollectionList
if(!getReadWriteLock().equals(children.getReadWriteLock()))
throw new IllegalArgumentException("If a CollectionList.Model returns EventLists, those EventLists must use the same ReadWriteLock as the CollectionList");
children.getPublisher().setRelatedSubject(this, CollectionList.this);
children.addListEventListener(this);
}
public E get(int index) {
return children.get(index);
}
public E remove(int index) {
// events will be fired from this call
return children.remove(index);
}
public E set(int index, E element) {
// events will be fired from this call
return children.set(index, element);
}
public void listChanged(ListEvent listChanges) {
int parentIndex = childElements.indexOfNode(node, (byte)1);
int absoluteIndex = getAbsoluteIndex(parentIndex);
int nextNodeIndex = getAbsoluteIndex(parentIndex+1);
// update the barcode
int firstChildIndex = absoluteIndex + 1;
int previousChildrenCount = nextNodeIndex - firstChildIndex;
if(previousChildrenCount > 0) barcode.remove(firstChildIndex, previousChildrenCount);
if(!children.isEmpty()) barcode.addWhite(firstChildIndex, children.size());
// get the offset of this child list
int childOffset = absoluteIndex - parentIndex;
// forward the offset event
updates.beginEvent();
while(listChanges.next()) {
int index = listChanges.getIndex();
int type = listChanges.getType();
int overallIndex = index + childOffset;
switch (type) {
case ListEvent.INSERT: updates.elementInserted(overallIndex, listChanges.getNewValue()); break;
case ListEvent.UPDATE: updates.elementUpdated(overallIndex, listChanges.getOldValue(), listChanges.getNewValue()); break;
case ListEvent.DELETE: updates.elementDeleted(overallIndex, listChanges.getOldValue()); break;
}
}
updates.commitEvent();
}
public void dispose() {
children.removeListEventListener(this);
children.getPublisher().clearRelatedSubject(this);
}
public String toString() {
return "[" + childElements.indexOfNode(node, (byte)0) + ":" + children + "]";
}
}
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