| /******************************************************************************* |
| * Copyright (c) 2008, 2009 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 215531) |
| * Matthew Hall - bugs 226765, 222991, 238296, 263956, 226292, 265051, |
| * 266038 |
| ******************************************************************************/ |
| |
| package org.eclipse.jface.internal.databinding.viewers; |
| |
| import org.eclipse.core.databinding.observable.IObservableCollection; |
| import org.eclipse.core.databinding.observable.Observables; |
| import org.eclipse.core.databinding.observable.masterdetail.IObservableFactory; |
| import org.eclipse.core.databinding.observable.masterdetail.MasterDetailObservables; |
| import org.eclipse.core.databinding.observable.set.IObservableSet; |
| import org.eclipse.core.databinding.observable.value.IObservableValue; |
| import org.eclipse.core.databinding.observable.value.WritableValue; |
| import org.eclipse.core.runtime.Assert; |
| import org.eclipse.jface.databinding.swt.SWTObservables; |
| import org.eclipse.jface.databinding.viewers.IViewerUpdater; |
| import org.eclipse.jface.viewers.AbstractListViewer; |
| import org.eclipse.jface.viewers.AbstractTableViewer; |
| import org.eclipse.jface.viewers.CheckboxTableViewer; |
| import org.eclipse.jface.viewers.IElementComparer; |
| import org.eclipse.jface.viewers.IStructuredContentProvider; |
| import org.eclipse.jface.viewers.StructuredViewer; |
| import org.eclipse.jface.viewers.Viewer; |
| import org.eclipse.swt.widgets.Display; |
| |
| /** |
| * NON-API - Abstract base class for content providers where the viewer input is |
| * expected to be an {@link IObservableCollection}. |
| * |
| * @since 1.2 |
| */ |
| public abstract class ObservableCollectionContentProvider implements |
| IStructuredContentProvider { |
| private Display display; |
| |
| private IObservableValue<Viewer> viewerObservable; |
| |
| /** |
| * Element comparer used by the viewer (may be null). |
| */ |
| protected IElementComparer comparer; |
| |
| private IObservableFactory<Viewer, IObservableSet<Object>> elementSetFactory; |
| |
| private final IViewerUpdater explicitViewerUpdater; |
| |
| /** |
| * Interface for sending updates to the viewer. |
| */ |
| protected IViewerUpdater viewerUpdater; |
| |
| /** |
| * Observable set of all elements known to the content provider. Subclasses |
| * must add new elements to this set <b>before</b> adding them to the |
| * viewer, and must remove old elements from this set <b>after</b> removing |
| * them from the viewer. |
| */ |
| protected IObservableSet<Object> knownElements; |
| private IObservableSet<Object> unmodifiableKnownElements; |
| |
| /** |
| * Observable set of known elements which have been realized in the viewer. |
| * Subclasses must add new elements to this set <b>after</b> adding them to |
| * the viewer, and must remove old elements from this set <b>before</b> |
| * removing them from the viewer. |
| */ |
| protected IObservableSet<Object> realizedElements; |
| private IObservableSet<Object> unmodifiableRealizedElements; |
| |
| private IObservableCollection<?> observableCollection; |
| |
| /** |
| * Constructs an ObservableCollectionContentProvider |
| * |
| * @param explicitViewerUpdater |
| */ |
| protected ObservableCollectionContentProvider( |
| IViewerUpdater explicitViewerUpdater) { |
| this.explicitViewerUpdater = explicitViewerUpdater; |
| |
| display = Display.getDefault(); |
| viewerObservable = new WritableValue<Viewer>( |
| SWTObservables.getRealm(display)); |
| viewerUpdater = null; |
| |
| elementSetFactory = new IObservableFactory<Viewer, IObservableSet<Object>>() { |
| public IObservableSet<Object> createObservable(Viewer target) { |
| IElementComparer comparer = null; |
| if (target instanceof StructuredViewer) |
| comparer = ((StructuredViewer) target).getComparer(); |
| return ObservableViewerElementSet.<Object> withComparer( |
| SWTObservables.getRealm(display), null, comparer); |
| } |
| }; |
| knownElements = MasterDetailObservables.detailSet(viewerObservable, |
| elementSetFactory, null); |
| unmodifiableKnownElements = Observables |
| .unmodifiableObservableSet(knownElements); |
| |
| observableCollection = null; |
| } |
| |
| public Object[] getElements(Object inputElement) { |
| if (observableCollection == null) |
| return new Object[0]; |
| |
| knownElements.addAll(observableCollection); |
| if (realizedElements != null) { |
| if (!realizedElements.equals(knownElements)) { |
| asyncUpdateRealizedElements(); |
| } |
| } |
| |
| return observableCollection.toArray(); |
| } |
| |
| private void asyncUpdateRealizedElements() { |
| if (realizedElements == null) |
| return; |
| display.asyncExec(new Runnable() { |
| public void run() { |
| if (realizedElements != null) { |
| realizedElements.addAll(knownElements); |
| } |
| } |
| }); |
| } |
| |
| public void dispose() { |
| if (observableCollection != null) |
| removeCollectionChangeListener(observableCollection); |
| |
| if (viewerObservable != null) { |
| viewerObservable.dispose(); |
| viewerObservable = null; |
| } |
| viewerUpdater = null; |
| knownElements = null; |
| unmodifiableKnownElements = null; |
| realizedElements = null; |
| unmodifiableRealizedElements = null; |
| display = null; |
| } |
| |
| public void inputChanged(Viewer viewer, Object oldInput, Object newInput) { |
| setViewer(viewer); |
| setInput(newInput); |
| } |
| |
| private void setViewer(Viewer viewer) { |
| viewerUpdater = createViewerUpdater(viewer); |
| comparer = getElementComparer(viewer); |
| viewerObservable.setValue(viewer); // (clears knownElements) |
| } |
| |
| private static IElementComparer getElementComparer(Viewer viewer) { |
| if (viewer instanceof StructuredViewer) |
| return ((StructuredViewer) viewer).getComparer(); |
| return null; |
| } |
| |
| IViewerUpdater createViewerUpdater(Viewer viewer) { |
| if (explicitViewerUpdater != null) |
| return explicitViewerUpdater; |
| if (viewer instanceof AbstractListViewer) |
| return new ListViewerUpdater((AbstractListViewer) viewer); |
| if (viewer instanceof CheckboxTableViewer) |
| return new CheckboxTableViewerUpdater((CheckboxTableViewer) viewer); |
| if (viewer instanceof AbstractTableViewer) |
| return new TableViewerUpdater((AbstractTableViewer) viewer); |
| throw new IllegalArgumentException( |
| "This content provider only works with AbstractTableViewer or AbstractListViewer"); //$NON-NLS-1$ |
| } |
| |
| void setInput(Object input) { |
| if (observableCollection != null) { |
| removeCollectionChangeListener(observableCollection); |
| observableCollection = null; |
| } |
| |
| knownElements.clear(); |
| if (realizedElements != null) |
| realizedElements.clear(); |
| |
| if (input != null) { |
| checkInput(input); |
| Assert.isTrue(input instanceof IObservableCollection, |
| "Input must be an IObservableCollection"); //$NON-NLS-1$ |
| observableCollection = (IObservableCollection<?>) input; |
| addCollectionChangeListener(observableCollection); |
| } |
| } |
| |
| /** |
| * Throws an exception if the input is not the correct type. |
| * |
| * @param input |
| * the input to check |
| */ |
| protected abstract void checkInput(Object input); |
| |
| /** |
| * Register for change event notification from the given collection. |
| * |
| * @param collection |
| * observable collection to listen to |
| */ |
| protected abstract void addCollectionChangeListener( |
| IObservableCollection<?> collection); |
| |
| /** |
| * Deregisters from change events notification on the given collection. |
| * |
| * @param collection |
| * observable collection to stop listening to |
| */ |
| protected abstract void removeCollectionChangeListener( |
| IObservableCollection<?> collection); |
| |
| /** |
| * Returns whether the viewer is disposed. Collection change listeners in |
| * subclasses should verify that the viewer is not disposed before sending |
| * any updates to the {@link ViewerUpdater viewer updater}. |
| * |
| * @return whether the viewer is disposed. |
| */ |
| protected final boolean isViewerDisposed() { |
| Viewer viewer = viewerObservable.getValue(); |
| return viewer == null || viewer.getControl() == null |
| || viewer.getControl().isDisposed(); |
| } |
| |
| /** |
| * 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 unmodifiable observable set of items that will need labels |
| */ |
| public IObservableSet<Object> getKnownElements() { |
| return unmodifiableKnownElements; |
| } |
| |
| /** |
| * 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<Object> getRealizedElements() { |
| if (realizedElements == null) { |
| realizedElements = MasterDetailObservables.detailSet( |
| viewerObservable, elementSetFactory, null); |
| unmodifiableRealizedElements = Observables |
| .unmodifiableObservableSet(realizedElements); |
| asyncUpdateRealizedElements(); |
| } |
| return unmodifiableRealizedElements; |
| } |
| } |