org.eclipse.jface.databinding.viewers.ObservableSetTreeContentProvider Maven / Gradle / Ivy
/*******************************************************************************
* Copyright (c) 2008, 2015 Matthew Hall and others.
*
* This program and the accompanying materials
* are made available under the terms of the Eclipse Public License 2.0
* which accompanies this distribution, and is available at
* https://www.eclipse.org/legal/epl-2.0/
*
* SPDX-License-Identifier: EPL-2.0
*
* Contributors:
* Matthew Hall - initial API and implementation (bug 207858)
* Matthew Hall - bugs 226765, 222991, 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.IObservablesListener;
import org.eclipse.core.databinding.observable.masterdetail.IObservableFactory;
import org.eclipse.core.databinding.observable.set.IObservableSet;
import org.eclipse.core.databinding.observable.set.ISetChangeListener;
import org.eclipse.core.databinding.observable.set.SetChangeEvent;
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 set factory} to obtain the
* elements of a tree. Objects of this class listen for changes to each
* {@link IObservableSet} created by the factory, and will insert and remove
* viewer elements to reflect the observed changes.
*
* @param type of the values that are provided by this object
*
* @noextend This class is not intended to be subclassed by clients.
* @since 1.2
*/
public class ObservableSetTreeContentProvider implements ITreeContentProvider {
private final ObservableCollectionTreeContentProvider impl;
private static class Impl extends ObservableCollectionTreeContentProvider {
Impl(IObservableFactory> setFactory,
TreeStructureAdvisor structureAdvisor) {
super(setFactory, structureAdvisor);
}
private class SetChangeListener implements ISetChangeListener {
final E parentElement;
public SetChangeListener(E parentElement) {
this.parentElement = parentElement;
}
@Override
public void handleSetChange(SetChangeEvent event) {
if (isViewerDisposed())
return;
Set localAdditions = event.diff.getAdditions();
Set localRemovals = event.diff.getRemovals();
Set knownElementAdditions = ViewerElementSet.withComparer(comparer);
knownElementAdditions.addAll(localAdditions);
knownElementAdditions.removeAll(knownElements);
Set knownElementRemovals = findPendingRemovals(parentElement, localRemovals);
knownElementRemovals.retainAll(knownElements);
knownElements.addAll(knownElementAdditions);
if (realizedElements != null) {
realizedElements.removeAll(knownElementRemovals);
}
for (E element : localAdditions) {
getOrCreateNode(element).addParent(parentElement);
}
viewerUpdater.add(parentElement, localAdditions.toArray());
viewerUpdater.remove(parentElement, localRemovals.toArray());
for (E element : localRemovals) {
TreeNode childNode = getExistingNode(element);
if (childNode != null)
childNode.removeParent(parentElement);
}
if (realizedElements != null) {
realizedElements.addAll(knownElementAdditions);
}
knownElements.removeAll(knownElementRemovals);
}
}
@Override
protected IObservablesListener createCollectionChangeListener(E parentElement) {
return new SetChangeListener(parentElement);
}
@Override
protected void addCollectionChangeListener(IObservableCollection collection, IObservablesListener listener) {
IObservableSet set = (IObservableSet) collection;
@SuppressWarnings("unchecked")
ISetChangeListener setListener = (ISetChangeListener) listener;
set.addSetChangeListener(setListener);
}
@Override
protected void removeCollectionChangeListener(
IObservableCollection collection, IObservablesListener listener) {
IObservableSet set = (IObservableSet) collection;
@SuppressWarnings("unchecked")
ISetChangeListener setListener = (ISetChangeListener) listener;
set.removeSetChangeListener(setListener);
}
}
/**
* Constructs an ObservableListTreeContentProvider using the given list
* factory. Must be called from the display thread.
*
* @param setFactory
* observable factory that produces an IObservableSet of children
* for a given parent element. Observable sets 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 null 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 ObservableSetTreeContentProvider(IObservableFactory> setFactory,
TreeStructureAdvisor structureAdvisor) {
impl = new Impl<>(setFactory, 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.
*
* The viewer should not be updated during this call, as it is in the
* process of being disposed.
*
*
* Note: Data binding content providers become unusable on
* disposal.
*
*/
@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();
}
}