/*******************************************************************************
* Copyright (c) 2007, 2015 Matthew Hall 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:
* Matthew Hall - initial API and implementation (bug 207858)
* Matthew Hall - bugs 226765, 222991, 226292, 266038, 283351
*******************************************************************************/
package org.eclipse.jface.databinding.viewers;
import java.util.Iterator;
import java.util.Set;
import org.eclipse.core.databinding.observable.IObservableCollection;
import org.eclipse.core.databinding.observable.IObservablesListener;
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.masterdetail.IObservableFactory;
import org.eclipse.core.databinding.observable.set.IObservableSet;
import org.eclipse.jface.internal.databinding.viewers.ObservableCollectionTreeContentProvider;
import org.eclipse.jface.internal.databinding.viewers.ViewerElementSet;
import org.eclipse.jface.viewers.AbstractTreeViewer;
import org.eclipse.jface.viewers.ITreeContentProvider;
import org.eclipse.jface.viewers.Viewer;
/**
* An {@link ITreeContentProvider} for use with an {@link AbstractTreeViewer},
* which uses the provided {@link IObservableFactory list factory} to obtain the
* elements of a tree. Object of this class listen for changes to each
* {@link IObservableList} created by the factory, and will insert and remove
* viewer elements to reflect the observed changes.
*
* @noextend This class is not intended to be subclassed by clients.
* @since 1.2
*/
public class ObservableListTreeContentProvider implements ITreeContentProvider {
private final ObservableCollectionTreeContentProvider impl;
private static class Impl extends ObservableCollectionTreeContentProvider {
private Viewer viewer;
public Impl(IObservableFactory listFactory,
TreeStructureAdvisor structureAdvisor) {
super(listFactory, structureAdvisor);
}
@Override
public void inputChanged(Viewer viewer, Object oldInput, Object newInput) {
this.viewer = viewer;
super.inputChanged(viewer, oldInput, newInput);
}
private class ListChangeListener implements IListChangeListener {
final Object parentElement;
public ListChangeListener(Object parentElement) {
this.parentElement = parentElement;
}
@Override
public void handleListChange(ListChangeEvent event) {
if (isViewerDisposed())
return;
// Determine which elements are being added and removed
final Set localKnownElementAdditions = ViewerElementSet
.withComparer(comparer);
final Set localKnownElementRemovals = ViewerElementSet
.withComparer(comparer);
final boolean[] suspendRedraw = new boolean[] { false };
event.diff.accept(new ListDiffVisitor() {
@Override
public void handleAdd(int index, Object element) {
localKnownElementAdditions.add(element);
}
@Override
public void handleRemove(int index, Object element) {
localKnownElementRemovals.add(element);
}
@Override
public void handleMove(int oldIndex, int newIndex,
Object element) {
suspendRedraw[0] = true;
// does not affect known elements
}
@Override
public void handleReplace(int index, Object oldElement,
Object newElement) {
suspendRedraw[0] = true;
super.handleReplace(index, oldElement, newElement);
}
});
localKnownElementRemovals.removeAll(event.getObservableList());
Set knownElementAdditions = ViewerElementSet
.withComparer(comparer);
knownElementAdditions.addAll(localKnownElementAdditions);
knownElementAdditions.removeAll(knownElements);
Set knownElementRemovals = findPendingRemovals(parentElement,
localKnownElementRemovals);
knownElementRemovals.retainAll(knownElements);
knownElements.addAll(knownElementAdditions);
if (realizedElements != null) {
realizedElements.removeAll(knownElementRemovals);
}
for (Iterator it = localKnownElementAdditions.iterator(); it
.hasNext();) {
getOrCreateNode(it.next()).addParent(parentElement);
}
if (suspendRedraw[0])
viewer.getControl().setRedraw(false);
try {
event.diff.accept(new ListDiffVisitor() {
@Override
public void handleAdd(int index, Object child) {
viewerUpdater.insert(parentElement, child, index);
}
@Override
public void handleRemove(int index, Object child) {
viewerUpdater.remove(parentElement, child, index);
}
@Override
public void handleReplace(int index, Object oldChild,
Object newChild) {
viewerUpdater.replace(parentElement, oldChild,
newChild, index);
}
@Override
public void handleMove(int oldIndex, int newIndex,
Object child) {
viewerUpdater.move(parentElement, child, oldIndex,
newIndex);
}
});
} finally {
if (suspendRedraw[0])
viewer.getControl().setRedraw(true);
}
for (Iterator it = localKnownElementRemovals.iterator(); it
.hasNext();) {
TreeNode node = getExistingNode(it.next());
if (node != null) {
node.removeParent(parentElement);
}
}
if (realizedElements != null) {
realizedElements.addAll(knownElementAdditions);
}
knownElements.removeAll(knownElementRemovals);
}
}
@Override
protected IObservablesListener createCollectionChangeListener(
Object parentElement) {
return new ListChangeListener(parentElement);
}
@Override
protected void addCollectionChangeListener(
IObservableCollection collection, IObservablesListener listener) {
IObservableList list = (IObservableList) collection;
IListChangeListener listListener = (IListChangeListener) listener;
list.addListChangeListener(listListener);
}
@Override
protected void removeCollectionChangeListener(
IObservableCollection collection, IObservablesListener listener) {
IObservableList list = (IObservableList) collection;
IListChangeListener listListener = (IListChangeListener) listener;
list.removeListChangeListener(listListener);
}
}
/**
* Constructs an ObservableListTreeContentProvider using the given list
* factory. Must be called from the display thread.
*
* @param listFactory
* observable factory that produces an IObservableList of
* children for a given parent element. Observable lists created
* by this factory must be on the realm of the current display.
* @param structureAdvisor
* an advisor that will be consulted from the implementations of
* the {@link #getParent(Object)} and
* {@link #hasChildren(Object)} methods, or <code>null</code> if
* no advisor is available. It is recommended that clients pass a
* non-null advisor if they can provide additional structural
* information about the tree.
*/
public ObservableListTreeContentProvider(IObservableFactory listFactory,
TreeStructureAdvisor structureAdvisor) {
impl = new Impl(listFactory, structureAdvisor);
}
@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);
}
@Override
public boolean hasChildren(Object element) {
return impl.hasChildren(element);
}
@Override
public Object[] getChildren(Object parentElement) {
return impl.getChildren(parentElement);
}
@Override
public Object getParent(Object element) {
return impl.getParent(element);
}
/**
* 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();
}
}