| /******************************************************************************* |
| * 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 |
| * Brad Reynolds - bug 116920 |
| *******************************************************************************/ |
| package org.eclipse.jface.databinding.viewers; |
| |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Set; |
| |
| import org.eclipse.core.databinding.observable.Diffs; |
| import org.eclipse.core.databinding.observable.IStaleListener; |
| import org.eclipse.core.databinding.observable.StaleEvent; |
| import org.eclipse.core.databinding.observable.set.IObservableSet; |
| import org.eclipse.core.databinding.observable.set.ISetChangeListener; |
| import org.eclipse.core.databinding.observable.set.ObservableSet; |
| import org.eclipse.core.databinding.observable.set.SetChangeEvent; |
| import org.eclipse.jface.databinding.swt.SWTObservables; |
| import org.eclipse.jface.viewers.AbstractListViewer; |
| import org.eclipse.jface.viewers.AbstractTableViewer; |
| import org.eclipse.jface.viewers.IStructuredContentProvider; |
| import org.eclipse.jface.viewers.Viewer; |
| import org.eclipse.swt.widgets.Display; |
| |
| /** |
| * This class can be used as a content provider for an |
| * {@link AbstractTableViewer} or {@link AbstractListViewer} and will provide |
| * elements of an {@link IObservableSet} when set as the viewer's input. Objects |
| * of this class will listen for changes to the observable set and, based on the |
| * observed changes, call corresponding update methods on the viewer. |
| * |
| * <p> |
| * This class is not intended to be subclassed by clients. |
| * </p> |
| * |
| * @since 1.1 |
| * |
| */ |
| public class ObservableSetContentProvider implements |
| IStructuredContentProvider { |
| |
| private class KnownElementsSet extends ObservableSet { |
| |
| KnownElementsSet(Set wrappedSet) { |
| super(SWTObservables.getRealm(Display.getDefault()), wrappedSet, Object.class); |
| } |
| |
| void doFireDiff(Set added, Set removed) { |
| fireSetChange(Diffs.createSetDiff(added, removed)); |
| } |
| |
| void doFireStale(boolean isStale) { |
| if (isStale) { |
| fireStale(); |
| } else { |
| fireChange(); |
| } |
| } |
| |
| void doSetWrappedSet(Set set) { |
| this.wrappedSet = set; |
| } |
| } |
| |
| private IObservableSet readableSet; |
| |
| private Viewer viewer; |
| |
| /** |
| * This readableSet returns the same elements as the input readableSet. |
| * However, it only fires events AFTER the elements have been added or |
| * removed from the viewer. |
| */ |
| private KnownElementsSet knownElements; |
| |
| private ISetChangeListener listener = new ISetChangeListener() { |
| |
| public void handleSetChange(SetChangeEvent event) { |
| boolean wasStale = knownElements.isStale(); |
| if (isDisposed()) { |
| return; |
| } |
| doDiff(event.diff.getAdditions(), event.diff.getRemovals(), true); |
| if (!wasStale && event.getObservableSet().isStale()) { |
| knownElements.doFireStale(true); |
| } |
| } |
| }; |
| |
| private IStaleListener staleListener = new IStaleListener() { |
| public void handleStale(StaleEvent event) { |
| knownElements.doFireStale(event.getObservable().isStale()); |
| } |
| }; |
| |
| /** |
| * |
| */ |
| public ObservableSetContentProvider() { |
| readableSet = new ObservableSet(SWTObservables.getRealm(Display.getDefault()), |
| Collections.EMPTY_SET, Object.class) { |
| }; |
| knownElements = new KnownElementsSet(readableSet); |
| } |
| |
| public void dispose() { |
| setInput(null); |
| } |
| |
| private void doDiff(Set added, Set removed, boolean updateViewer) { |
| knownElements.doFireDiff(added, Collections.EMPTY_SET); |
| |
| if (updateViewer) { |
| Object[] toAdd = added.toArray(); |
| if (viewer instanceof AbstractTableViewer) { |
| AbstractTableViewer tv = (AbstractTableViewer) viewer; |
| tv.add(toAdd); |
| } else if (viewer instanceof AbstractListViewer) { |
| AbstractListViewer lv = (AbstractListViewer) viewer; |
| lv.add(toAdd); |
| } |
| Object[] toRemove = removed.toArray(); |
| if (viewer instanceof AbstractTableViewer) { |
| AbstractTableViewer tv = (AbstractTableViewer) viewer; |
| tv.remove(toRemove); |
| } else if (viewer instanceof AbstractListViewer) { |
| AbstractListViewer lv = (AbstractListViewer) viewer; |
| lv.remove(toRemove); |
| } |
| } |
| knownElements.doFireDiff(Collections.EMPTY_SET, removed); |
| } |
| |
| public Object[] getElements(Object inputElement) { |
| return readableSet.toArray(); |
| } |
| |
| /** |
| * Returns the readableSet of elements known to this content provider. Items |
| * are added to this readableSet before being added to the viewer, and they |
| * are removed after being removed from the viewer. The readableSet is |
| * always updated after 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 knownElements; |
| } |
| |
| public void inputChanged(Viewer viewer, Object oldInput, Object newInput) { |
| this.viewer = viewer; |
| |
| if (!(viewer instanceof AbstractTableViewer || viewer instanceof AbstractListViewer)) { |
| throw new IllegalArgumentException( |
| "This content provider only works with AbstractTableViewer or AbstractListViewer"); //$NON-NLS-1$ |
| } |
| |
| if (newInput != null && !(newInput instanceof IObservableSet)) { |
| throw new IllegalArgumentException( |
| "This content provider only works with input of type IObservableSet"); //$NON-NLS-1$ |
| } |
| |
| setInput((IObservableSet) newInput); |
| } |
| |
| private boolean isDisposed() { |
| return viewer.getControl() == null || viewer.getControl().isDisposed(); |
| } |
| |
| private void setInput(IObservableSet newSet) { |
| boolean updateViewer = true; |
| if (newSet == null) { |
| newSet = new ObservableSet(SWTObservables.getRealm(Display.getDefault()), Collections.EMPTY_SET, Object.class) { |
| }; |
| // don't update the viewer - its input is null |
| updateViewer = false; |
| } |
| |
| boolean wasStale = false; |
| if (readableSet != null) { |
| wasStale = readableSet.isStale(); |
| readableSet.removeSetChangeListener(listener); |
| readableSet.removeStaleListener(staleListener); |
| } |
| |
| HashSet additions = new HashSet(); |
| HashSet removals = new HashSet(); |
| |
| additions.addAll(newSet); |
| additions.removeAll(readableSet); |
| |
| removals.addAll(readableSet); |
| removals.removeAll(newSet); |
| |
| readableSet = newSet; |
| knownElements.doSetWrappedSet(readableSet); |
| |
| doDiff(additions, removals, updateViewer); |
| |
| if (readableSet != null) { |
| readableSet.addSetChangeListener(listener); |
| readableSet.addStaleListener(staleListener); |
| } |
| |
| boolean isStale = (readableSet != null && readableSet.isStale()); |
| if (isStale != wasStale) { |
| knownElements.doFireStale(isStale); |
| } |
| } |
| |
| } |