| /******************************************************************************* |
| * Copyright (c) 2008 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 218269) |
| ******************************************************************************/ |
| |
| package org.eclipse.core.internal.databinding.observable; |
| |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| 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.core.databinding.observable.set.SetDiff; |
| import org.eclipse.core.databinding.observable.value.IObservableValue; |
| import org.eclipse.core.databinding.observable.value.IValueChangeListener; |
| import org.eclipse.core.databinding.observable.value.ValueChangeEvent; |
| import org.eclipse.core.runtime.Assert; |
| import org.eclipse.core.runtime.IStatus; |
| |
| /** |
| * @since 3.3 |
| * |
| */ |
| public class ValidatedObservableSet extends ObservableSet { |
| private IObservableSet target; |
| private IObservableValue validationStatus; |
| |
| // Only true when out of sync with target due to validation status |
| private boolean stale; |
| |
| // True when validation status changes from invalid to valid. |
| private boolean computeNextDiff = false; |
| |
| private boolean updatingTarget = false; |
| |
| private ISetChangeListener targetChangeListener = new ISetChangeListener() { |
| public void handleSetChange(SetChangeEvent event) { |
| if (updatingTarget) |
| return; |
| IStatus status = (IStatus) validationStatus.getValue(); |
| if (isValid(status)) { |
| if (stale) { |
| // this.stale means we are out of sync with target, |
| // so reset wrapped list to exactly mirror target |
| stale = false; |
| updateWrappedSet(new HashSet(target)); |
| } else { |
| SetDiff diff = event.diff; |
| if (computeNextDiff) { |
| diff = Diffs.computeSetDiff(wrappedSet, target); |
| computeNextDiff = false; |
| } |
| applyDiff(diff, wrappedSet); |
| fireSetChange(diff); |
| } |
| } else { |
| makeStale(); |
| } |
| } |
| }; |
| |
| private IStaleListener targetStaleListener = new IStaleListener() { |
| public void handleStale(StaleEvent staleEvent) { |
| fireStale(); |
| } |
| }; |
| |
| private IValueChangeListener validationStatusChangeListener = new IValueChangeListener() { |
| public void handleValueChange(ValueChangeEvent event) { |
| IStatus oldStatus = (IStatus) event.diff.getOldValue(); |
| IStatus newStatus = (IStatus) event.diff.getNewValue(); |
| if (stale && !isValid(oldStatus) && isValid(newStatus)) { |
| // this.stale means we are out of sync with target, |
| // reset wrapped set to exactly mirror target |
| stale = false; |
| updateWrappedSet(new HashSet(target)); |
| |
| // If the validation status becomes valid because of a change in |
| // target observable |
| computeNextDiff = true; |
| } |
| } |
| }; |
| |
| /** |
| * @param target |
| * @param validationStatus |
| */ |
| public ValidatedObservableSet(final IObservableSet target, |
| final IObservableValue validationStatus) { |
| super(target.getRealm(), new HashSet(target), target.getElementType()); |
| Assert.isNotNull(validationStatus, |
| "Validation status observable cannot be null"); //$NON-NLS-1$ |
| Assert |
| .isTrue(target.getRealm().equals(validationStatus.getRealm()), |
| "Target and validation status observables must be on the same realm"); //$NON-NLS-1$ |
| this.target = target; |
| this.validationStatus = validationStatus; |
| target.addSetChangeListener(targetChangeListener); |
| target.addStaleListener(targetStaleListener); |
| validationStatus.addValueChangeListener(validationStatusChangeListener); |
| } |
| |
| private void updateWrappedSet(Set newSet) { |
| Set oldSet = wrappedSet; |
| SetDiff diff = Diffs.computeSetDiff(oldSet, newSet); |
| wrappedSet = newSet; |
| fireSetChange(diff); |
| } |
| |
| private static boolean isValid(IStatus status) { |
| return status.isOK() || status.matches(IStatus.INFO | IStatus.WARNING); |
| } |
| |
| private void applyDiff(SetDiff diff, Set set) { |
| for (Iterator iterator = diff.getRemovals().iterator(); iterator |
| .hasNext();) { |
| set.remove(iterator.next()); |
| } |
| for (Iterator iterator = diff.getAdditions().iterator(); iterator |
| .hasNext();) { |
| set.add(iterator.next()); |
| } |
| } |
| |
| private void makeStale() { |
| if (!stale) { |
| stale = true; |
| fireStale(); |
| } |
| } |
| |
| private void updateTargetSet(SetDiff diff) { |
| updatingTarget = true; |
| try { |
| if (stale) { |
| stale = false; |
| applyDiff(Diffs.computeSetDiff(target, wrappedSet), target); |
| } else { |
| applyDiff(diff, target); |
| } |
| } finally { |
| updatingTarget = false; |
| } |
| } |
| |
| public boolean isStale() { |
| getterCalled(); |
| return stale || target.isStale(); |
| } |
| |
| public boolean add(Object o) { |
| getterCalled(); |
| boolean changed = wrappedSet.add(o); |
| if (changed) { |
| SetDiff diff = Diffs.createSetDiff(Collections.singleton(o), |
| Collections.EMPTY_SET); |
| updateTargetSet(diff); |
| fireSetChange(diff); |
| } |
| return changed; |
| } |
| |
| public boolean addAll(Collection c) { |
| getterCalled(); |
| HashSet set = new HashSet(wrappedSet); |
| boolean changed = set.addAll(c); |
| if (changed) { |
| SetDiff diff = Diffs.computeSetDiff(wrappedSet, set); |
| wrappedSet = set; |
| updateTargetSet(diff); |
| fireSetChange(diff); |
| } |
| return changed; |
| } |
| |
| public void clear() { |
| getterCalled(); |
| if (isEmpty()) |
| return; |
| SetDiff diff = Diffs.createSetDiff(Collections.EMPTY_SET, wrappedSet); |
| wrappedSet = new HashSet(); |
| updateTargetSet(diff); |
| fireSetChange(diff); |
| } |
| |
| public Iterator iterator() { |
| getterCalled(); |
| final Iterator wrappedIterator = wrappedSet.iterator(); |
| return new Iterator() { |
| Object last = null; |
| |
| public boolean hasNext() { |
| return wrappedIterator.hasNext(); |
| } |
| |
| public Object next() { |
| return last = wrappedIterator.next(); |
| } |
| |
| public void remove() { |
| wrappedIterator.remove(); |
| SetDiff diff = Diffs.createSetDiff(Collections.EMPTY_SET, |
| Collections.singleton(last)); |
| updateTargetSet(diff); |
| fireSetChange(diff); |
| } |
| }; |
| } |
| |
| public boolean remove(Object o) { |
| getterCalled(); |
| boolean changed = wrappedSet.remove(o); |
| if (changed) { |
| SetDiff diff = Diffs.createSetDiff(Collections.EMPTY_SET, |
| Collections.singleton(o)); |
| updateTargetSet(diff); |
| fireSetChange(diff); |
| } |
| return changed; |
| } |
| |
| public boolean removeAll(Collection c) { |
| getterCalled(); |
| Set set = new HashSet(wrappedSet); |
| boolean changed = set.removeAll(c); |
| if (changed) { |
| SetDiff diff = Diffs.computeSetDiff(wrappedSet, set); |
| wrappedSet = set; |
| updateTargetSet(diff); |
| fireSetChange(diff); |
| } |
| return changed; |
| } |
| |
| public boolean retainAll(Collection c) { |
| getterCalled(); |
| Set set = new HashSet(wrappedSet); |
| boolean changed = set.retainAll(c); |
| if (changed) { |
| SetDiff diff = Diffs.computeSetDiff(wrappedSet, set); |
| wrappedSet = set; |
| updateTargetSet(diff); |
| fireSetChange(diff); |
| } |
| return changed; |
| } |
| |
| public synchronized void dispose() { |
| target.removeSetChangeListener(targetChangeListener); |
| target.removeStaleListener(targetStaleListener); |
| validationStatus |
| .removeValueChangeListener(validationStatusChangeListener); |
| super.dispose(); |
| } |
| } |