/*******************************************************************************
* Copyright (c) 2006, 2015 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
* Tom Schindl<tom.schindl@bestsolution.at> - bugfix in: 214355
* Matthew Hall - bugs 215531, 226765, 222991, 238296, 226292, 266038,
* 283351
*******************************************************************************/
package org.eclipse.jface.databinding.viewers;
import java.util.Set;
import org.eclipse.core.databinding.observable.IObservableCollection;
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.ListDiffVisitor;
import org.eclipse.core.databinding.observable.set.IObservableSet;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.internal.databinding.viewers.ObservableCollectionContentProvider;
import org.eclipse.jface.internal.databinding.viewers.ViewerElementSet;
import org.eclipse.jface.viewers.AbstractListViewer;
import org.eclipse.jface.viewers.AbstractTableViewer;
import org.eclipse.jface.viewers.IStructuredContentProvider;
import org.eclipse.jface.viewers.Viewer;
/**
* A {@link IStructuredContentProvider content provider} for
* {@link AbstractTableViewer} or {@link AbstractListViewer} that provides
* elements of an {@link IObservableList} when set as the viewer's input.
* Objects of this class listen for changes to the observable list, and will
* insert and remove viewer elements to reflect observed changes.
*
* @noextend This class is not intended to be subclassed by clients.
* @since 1.1
*/
public class ObservableListContentProvider implements
IStructuredContentProvider {
private ObservableCollectionContentProvider impl;
private static class Impl extends ObservableCollectionContentProvider
implements IListChangeListener {
private Viewer viewer;
Impl(IViewerUpdater explicitViewerUpdater) {
super(explicitViewerUpdater);
}
@Override
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
this.viewer = viewer;
super.inputChanged(viewer, oldInput, newInput);
}
@Override
protected void checkInput(Object input) {
Assert.isTrue(input instanceof IObservableList,
"This content provider only works with input of type IObservableList"); //$NON-NLS-1$
}
@Override
protected void addCollectionChangeListener(
IObservableCollection collection) {
((IObservableList) collection).addListChangeListener(this);
}
@Override
protected void removeCollectionChangeListener(
IObservableCollection collection) {
((IObservableList) collection).removeListChangeListener(this);
}
@Override
public void handleListChange(ListChangeEvent event) {
if (isViewerDisposed())
return;
// Determine which elements were added and removed
final Set knownElementAdditions = ViewerElementSet
.withComparer(comparer);
final Set knownElementRemovals = ViewerElementSet
.withComparer(comparer);
final boolean[] suspendRedraw = new boolean[] { false };
event.diff.accept(new ListDiffVisitor() {
@Override
public void handleAdd(int index, Object element) {
knownElementAdditions.add(element);
}
@Override
public void handleRemove(int index, Object element) {
knownElementRemovals.add(element);
}
@Override
public void handleMove(int oldIndex, int newIndex,
Object element) {
suspendRedraw[0] = true;
super.handleMove(oldIndex, newIndex, element);
}
@Override
public void handleReplace(int index, Object oldElement,
Object newElement) {
suspendRedraw[0] = true;
super.handleReplace(index, oldElement, newElement);
}
});
knownElementAdditions.removeAll(knownElements);
knownElementRemovals.removeAll(event.getObservableList());
knownElements.addAll(knownElementAdditions);
if (realizedElements != null) {
realizedElements.removeAll(knownElementRemovals);
}
if (suspendRedraw[0])
viewer.getControl().setRedraw(false);
try {
event.diff.accept(new ListDiffVisitor() {
@Override
public void handleAdd(int index, Object element) {
viewerUpdater.insert(element, index);
}
@Override
public void handleRemove(int index, Object element) {
viewerUpdater.remove(element, index);
}
@Override
public void handleReplace(int index, Object oldElement,
Object newElement) {
viewerUpdater.replace(oldElement, newElement, index);
}
@Override
public void handleMove(int oldIndex, int newIndex,
Object element) {
viewerUpdater.move(element, oldIndex, newIndex);
}
});
} finally {
if (suspendRedraw[0])
viewer.getControl().setRedraw(true);
}
if (realizedElements != null) {
realizedElements.addAll(knownElementAdditions);
}
knownElements.removeAll(knownElementRemovals);
}
}
/**
* Constructs an ObservableListContentProvider. Must be called from the
* display thread.
*/
public ObservableListContentProvider() {
this(null);
}
/**
* Constructs an ObservableListContentProvider with the given viewer
* updater. Must be called from the display thread.
*
* @param viewerUpdater
* the viewer updater to use when elements are added, removed,
* moved or replaced in the input observable list.
* @since 1.3
*/
public ObservableListContentProvider(IViewerUpdater viewerUpdater) {
impl = new Impl(viewerUpdater);
}
@Override
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
impl.inputChanged(viewer, oldInput, newInput);
}
@Override
public Object[] getElements(Object inputElement) {
return impl.getElements(inputElement);
}
/**
* Disposes of this content provider. This is called by the viewer when a
* content provider is replaced, or when the viewer itself is disposed.
* <p>
* The viewer should not be updated during this call, as it is in the
* process of being disposed.
* </p>
* <p>
* <em>Note:</em> Data binding content providers become unusable on
* disposal.
* </p>
*/
@Override
public void dispose() {
impl.dispose();
}
/**
* Returns 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. This is intended for use
* by label providers, as it will always return the items that need labels.
*
* @return readableSet of items that will need labels
*/
public IObservableSet getKnownElements() {
return impl.getKnownElements();
}
/**
* Returns the set of known elements which have been realized in the viewer.
* Clients may track this set in order to perform custom actions on elements
* while they are known to be present in the viewer.
*
* @return the set of known elements which have been realized in the viewer.
* @since 1.3
*/
public IObservableSet getRealizedElements() {
return impl.getRealizedElements();
}
}