/*******************************************************************************
* Copyright (c) 2006, 2007 IBM Corporation and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jface.databinding.viewers;
import org.eclipse.core.databinding.observable.list.IListChangeListener;
import org.eclipse.core.databinding.observable.list.IObservableList;
import org.eclipse.core.databinding.observable.list.ListChangeEvent;
import org.eclipse.core.databinding.observable.list.ListDiffEntry;
import org.eclipse.core.databinding.observable.list.WritableList;
import org.eclipse.core.databinding.observable.set.IObservableSet;
import org.eclipse.core.databinding.observable.set.WritableSet;
import org.eclipse.jface.databinding.swt.SWTObservables;
import org.eclipse.jface.viewers.AbstractListViewer;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.swt.widgets.Display;
/**
* @since 1.1
*
*/
public class ObservableListContentProvider implements
IStructuredContentProvider {
private IObservableList observableList;
private Viewer viewer;
private IListChangeListener listener = new IListChangeListener() {
public void handleListChange(ListChangeEvent event) {
if (viewer.getControl().isDisposed()) {
return;
}
ListDiffEntry[] differences = event.diff.getDifferences();
for (int i = 0; i < differences.length; i++) {
ListDiffEntry entry = differences[i];
if (entry.isAddition()) {
knownElements.add(entry.getElement());
if (viewer instanceof AbstractListViewer) {
((AbstractListViewer) viewer).add(entry.getElement());
} else {
((TableViewer) viewer).insert(entry.getElement(), entry
.getPosition());
}
} else {
if (viewer instanceof AbstractListViewer) {
((AbstractListViewer) viewer)
.remove(entry.getElement());
} else {
((TableViewer) viewer).remove(entry.getElement());
}
knownElements.remove(entry.getElement());
}
}
}
};
private IObservableSet knownElements;
/**
*
*/
public ObservableListContentProvider() {
observableList = new WritableList(SWTObservables.getRealm(Display.getDefault()));
knownElements = new WritableSet(SWTObservables.getRealm(Display.getDefault()));
}
public Object[] getElements(Object inputElement) {
return observableList.toArray();
}
public void dispose() {
observableList.removeListChangeListener(listener);
}
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
this.viewer = viewer;
if (!(viewer instanceof TableViewer || viewer instanceof AbstractListViewer)) {
// use reflection to avoid 3.3 dependency:
Class abstractTableViewerClass = null;
try {
abstractTableViewerClass = Class.forName("org.eclipse.jface.viewers.AbstractTableViewer"); //$NON-NLS-1$
} catch(Exception ex) {
// ignore, we might be running against 3.2
}
if (abstractTableViewerClass == null || !abstractTableViewerClass.isInstance(viewer)) {
throw new IllegalArgumentException(
"This content provider only works with (Abstract)TableViewer or AbstractListViewer"); //$NON-NLS-1$
}
}
if (newInput != null && !(newInput instanceof IObservableList)) {
throw new IllegalArgumentException(
"This content provider only works with input of type IObservableList"); //$NON-NLS-1$
}
setInput((IObservableList) newInput);
}
/**
* @param list
*/
private void setInput(IObservableList list) {
if (list == null) {
list = new WritableList(SWTObservables.getRealm(Display.getDefault()));
}
if (observableList != null) {
observableList.removeListChangeListener(listener);
}
knownElements.clear();
observableList = list;
knownElements.addAll(list);
observableList.addListChangeListener(listener);
}
/**
* @return the set of elements known to this content provider. Label providers may track
* this set if they need to be notified about additions before the viewer sees the added
* element, and notified about removals after the element was removed from the viewer.
*/
public IObservableSet getKnownElements() {
return knownElements;
}
}