ca.odell.glazedlists.swing.DefaultEventListModel Maven / Gradle / Ivy
/* Glazed Lists (c) 2003-2006 */
/* http://publicobject.com/glazedlists/ publicobject.com,*/
/* O'Dell Engineering Ltd.*/
package ca.odell.glazedlists.swing;
import ca.odell.glazedlists.EventList;
import ca.odell.glazedlists.event.ListEvent;
import ca.odell.glazedlists.event.ListEventListener;
import java.awt.EventQueue;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JList;
import javax.swing.ListModel;
import javax.swing.SwingUtilities;
import javax.swing.event.ListDataEvent;
import javax.swing.event.ListDataListener;
/**
* A DefaultEventListModel adapts an EventList to the ListModel interface making it
* appropriate for use with a {@link JList}. Each element of the list
* corresponds to an element in the {@link ListModel}.
*
* The DefaultEventListModel class is not thread-safe. Unless
* otherwise noted, all methods are only safe to be called from the event
* dispatch thread. To do this programmatically, use {@link SwingUtilities#invokeAndWait(Runnable)}
* and wrap the source list (or some part of the source list's pipeline) using
* {@link GlazedListsSwing#swingThreadProxyList(EventList)}.
*
* @see Bug 14
* @see Bug 146
* @see Bug 177
* @see Bug 228
* @see SwingUtilities#invokeAndWait(Runnable)
*
* @author Jesse Wilson
* @author Holger Brands
*/
public class DefaultEventListModel implements ListEventListener, ListModel {
/** the source EventList */
protected EventList source;
/** indicator to dispose source list */
private boolean disposeSource;
/** whom to notify of data changes */
private final List listeners = new ArrayList();
/** recycle the list data event to prevent unnecessary object creation */
protected final MutableListDataEvent listDataEvent = new MutableListDataEvent(this);
/**
* Creates a new model that contains all objects located in the given
* source and reacts to any changes in the given
* source.
*
* @param source the EventList that provides the elements
*/
public DefaultEventListModel(EventList source) {
this(source, false);
}
/**
* Creates a new model that contains all objects located in the given
* source and reacts to any changes in the given
* source.
*
* @param source the EventList that provides the elements
* @param diposeSource true if the source list should be disposed when disposing
* this model, false otherwise
*/
protected DefaultEventListModel(EventList source, boolean disposeSource) {
this.source = source;
this.disposeSource = disposeSource;
this.source.addListEventListener(this);
}
/**
* For implementing the ListEventListener interface. This sends changes
* to the table which can repaint the table cells. It's checked that all natural
* calls to this method arrive on the Swing thread.
*
* This always sends discrete changes for the complete size of the list.
* It may be more efficient to implement a threshhold where a large list
* of changes are grouped together as a single change. This is how the
* ListTable accepts large change events.
*/
public void listChanged(ListEvent listChanges) {
if (!EventQueue.isDispatchThread())
throw new IllegalStateException("Events to " + this.getClass().getSimpleName() + " must arrive on the EDT - consider adding GlazedListsSwing.swingThreadProxyList(source) somewhere in your list pipeline");
// build an "optimized" ListDataEvent describing the precise range of rows in the first block
listChanges.nextBlock();
final int startIndex = listChanges.getBlockStartIndex();
final int endIndex = listChanges.getBlockEndIndex();
listDataEvent.setRange(startIndex, endIndex);
final int changeType = listChanges.getType();
switch (changeType) {
case ListEvent.INSERT: listDataEvent.setType(ListDataEvent.INTERVAL_ADDED); break;
case ListEvent.DELETE: listDataEvent.setType(ListDataEvent.INTERVAL_REMOVED); break;
case ListEvent.UPDATE: listDataEvent.setType(ListDataEvent.CONTENTS_CHANGED); break;
}
// if another block exists, fallback to using a generic "data changed" ListDataEvent
if (listChanges.nextBlock()) {
listDataEvent.setRange(0, Integer.MAX_VALUE);
listDataEvent.setType(ListDataEvent.CONTENTS_CHANGED);
}
fireListDataEvent(listDataEvent);
}
/**
* Returns the value at the specified index.
*
* @param index the requested index
* @return the value at index
*/
public Object getElementAt(int index) {
source.getReadWriteLock().readLock().lock();
try {
return source.get(index);
} finally {
source.getReadWriteLock().readLock().unlock();
}
}
/**
* Gets the size of the list.
*/
public int getSize() {
source.getReadWriteLock().readLock().lock();
try {
return source.size();
} finally {
source.getReadWriteLock().readLock().unlock();
}
}
/**
* Registers the specified ListDataListener to receive updates whenever
* this list changes.
*
* The specified ListDataListener must not save a
* reference to the ListDataEvent beyond the end of the notification
* method. This is because the ListDataEvent is re-used to increase
* the performance of this implementation.
*/
public void addListDataListener(ListDataListener listDataListener) {
listeners.add(listDataListener);
}
/**
* Deregisters the specified ListDataListener from receiving updates
* whenever this list changes.
*/
public void removeListDataListener(ListDataListener listDataListener) {
listeners.remove(listDataListener);
}
/**
* Notifies all ListDataListeners about one block of changes in the list.
*/
protected void fireListDataEvent(ListDataEvent listDataEvent) {
// notify all listeners about the event
for(int i = 0, n = listeners.size(); i < n; i++) {
ListDataListener listDataListener = listeners.get(i);
switch (listDataEvent.getType()) {
case ListDataEvent.CONTENTS_CHANGED: listDataListener.contentsChanged(listDataEvent); break;
case ListDataEvent.INTERVAL_ADDED: listDataListener.intervalAdded(listDataEvent); break;
case ListDataEvent.INTERVAL_REMOVED: listDataListener.intervalRemoved(listDataEvent); break;
}
}
}
/**
* Releases the resources consumed by this {@link DefaultEventListModel} so that it
* may eventually be garbage collected.
*
*
An {@link DefaultEventListModel} will be garbage collected without a call to
* {@link #dispose()}, but not before its source {@link EventList} is garbage
* collected. By calling {@link #dispose()}, you allow the {@link DefaultEventListModel}
* to be garbage collected before its source {@link EventList}. This is
* necessary for situations where an {@link DefaultEventListModel} is short-lived but
* its source {@link EventList} is long-lived.
*
*
Warning: It is an error
* to call any method on an {@link DefaultEventListModel} after it has been disposed.
* As such, this {@link DefaultEventListModel} should be detached from its
* corresponding Component before it is disposed.
*/
public void dispose() {
source.removeListEventListener(this);
if (disposeSource) source.dispose();
// this encourages exceptions to be thrown if this model is incorrectly accessed again
source = null;
}
}