| /******************************************************************************* |
| * 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 124684) |
| * IBM Corporation - through ListBinding.java |
| ******************************************************************************/ |
| |
| package org.eclipse.core.databinding; |
| |
| import java.util.Collections; |
| import java.util.Iterator; |
| |
| import org.eclipse.core.databinding.observable.Diffs; |
| 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.core.databinding.observable.set.SetDiff; |
| import org.eclipse.core.databinding.observable.value.IObservableValue; |
| import org.eclipse.core.databinding.observable.value.WritableValue; |
| import org.eclipse.core.internal.databinding.BindingStatus; |
| import org.eclipse.core.runtime.IStatus; |
| import org.eclipse.core.runtime.MultiStatus; |
| import org.eclipse.core.runtime.Status; |
| |
| /** |
| * @since 1.1 |
| * |
| */ |
| public class SetBinding extends Binding { |
| |
| private UpdateSetStrategy targetToModel; |
| private UpdateSetStrategy modelToTarget; |
| private IObservableValue validationStatusObservable; |
| private boolean updatingTarget; |
| private boolean updatingModel; |
| |
| private ISetChangeListener targetChangeListener = new ISetChangeListener() { |
| public void handleSetChange(SetChangeEvent event) { |
| if (!updatingTarget) { |
| doUpdate((IObservableSet) getTarget(), |
| (IObservableSet) getModel(), event.diff, targetToModel, |
| false, false); |
| } |
| } |
| }; |
| |
| private ISetChangeListener modelChangeListener = new ISetChangeListener() { |
| public void handleSetChange(SetChangeEvent event) { |
| if (!updatingModel) { |
| doUpdate((IObservableSet) getModel(), |
| (IObservableSet) getTarget(), event.diff, |
| modelToTarget, false, false); |
| } |
| } |
| }; |
| |
| /** |
| * @param target |
| * @param model |
| * @param modelToTargetStrategy |
| * @param targetToModelStrategy |
| */ |
| public SetBinding(IObservableSet target, IObservableSet model, |
| UpdateSetStrategy targetToModelStrategy, |
| UpdateSetStrategy modelToTargetStrategy) { |
| super(target, model); |
| this.targetToModel = targetToModelStrategy; |
| this.modelToTarget = modelToTargetStrategy; |
| if ((targetToModel.getUpdatePolicy() & UpdateSetStrategy.POLICY_UPDATE) != 0) { |
| target.addSetChangeListener(targetChangeListener); |
| } else { |
| targetChangeListener = null; |
| } |
| if ((modelToTarget.getUpdatePolicy() & UpdateSetStrategy.POLICY_UPDATE) != 0) { |
| model.addSetChangeListener(modelChangeListener); |
| } else { |
| modelChangeListener = null; |
| } |
| } |
| |
| public IObservableValue getValidationStatus() { |
| return validationStatusObservable; |
| } |
| |
| protected void preInit() { |
| validationStatusObservable = new WritableValue(context |
| .getValidationRealm(), Status.OK_STATUS, IStatus.class); |
| } |
| |
| protected void postInit() { |
| if (modelToTarget.getUpdatePolicy() == UpdateSetStrategy.POLICY_UPDATE) { |
| updateModelToTarget(); |
| } |
| if (targetToModel.getUpdatePolicy() != UpdateSetStrategy.POLICY_NEVER) { |
| validateTargetToModel(); |
| } |
| } |
| |
| public void updateModelToTarget() { |
| final IObservableSet modelSet = (IObservableSet) getModel(); |
| modelSet.getRealm().exec(new Runnable() { |
| public void run() { |
| SetDiff diff = Diffs.computeSetDiff(Collections.EMPTY_SET, |
| modelSet); |
| doUpdate(modelSet, (IObservableSet) getTarget(), diff, |
| modelToTarget, true, true); |
| } |
| }); |
| } |
| |
| public void updateTargetToModel() { |
| final IObservableSet targetSet = (IObservableSet) getTarget(); |
| targetSet.getRealm().exec(new Runnable() { |
| public void run() { |
| SetDiff diff = Diffs.computeSetDiff(Collections.EMPTY_SET, |
| targetSet); |
| doUpdate(targetSet, (IObservableSet) getModel(), diff, |
| targetToModel, true, true); |
| } |
| }); |
| } |
| |
| public void validateModelToTarget() { |
| // nothing for now |
| } |
| |
| public void validateTargetToModel() { |
| // nothing for now |
| } |
| |
| /* |
| * This method may be moved to UpdateSetStrategy in the future if clients |
| * need more control over how the two sets are kept in sync. |
| */ |
| private void doUpdate(final IObservableSet source, |
| final IObservableSet destination, final SetDiff diff, |
| final UpdateSetStrategy updateSetStrategy, final boolean explicit, |
| final boolean clearDestination) { |
| final int policy = updateSetStrategy.getUpdatePolicy(); |
| if (policy == UpdateSetStrategy.POLICY_NEVER) |
| return; |
| if (policy == UpdateSetStrategy.POLICY_ON_REQUEST && !explicit) |
| return; |
| destination.getRealm().exec(new Runnable() { |
| public void run() { |
| if (destination == getTarget()) { |
| updatingTarget = true; |
| } else { |
| updatingModel = true; |
| } |
| MultiStatus multiStatus = BindingStatus.ok(); |
| |
| try { |
| if (clearDestination) { |
| destination.clear(); |
| } |
| |
| for (Iterator iterator = diff.getRemovals().iterator(); iterator |
| .hasNext();) { |
| IStatus setterStatus = updateSetStrategy.doRemove( |
| destination, updateSetStrategy.convert(iterator |
| .next())); |
| |
| mergeStatus(multiStatus, setterStatus); |
| // TODO - at this point, the two sets |
| // will be out of sync if an error |
| // occurred... |
| } |
| |
| for (Iterator iterator = diff.getAdditions().iterator(); iterator |
| .hasNext();) { |
| IStatus setterStatus = updateSetStrategy.doAdd( |
| destination, updateSetStrategy.convert(iterator |
| .next())); |
| |
| mergeStatus(multiStatus, setterStatus); |
| // TODO - at this point, the two sets |
| // will be out of sync if an error |
| // occurred... |
| } |
| } finally { |
| validationStatusObservable.setValue(multiStatus); |
| |
| if (destination == getTarget()) { |
| updatingTarget = false; |
| } else { |
| updatingModel = false; |
| } |
| } |
| } |
| }); |
| } |
| |
| /** |
| * Merges the provided <code>newStatus</code> into the |
| * <code>multiStatus</code>. |
| * |
| * @param multiStatus |
| * @param newStatus |
| */ |
| /* package */void mergeStatus(MultiStatus multiStatus, IStatus newStatus) { |
| if (!newStatus.isOK()) { |
| multiStatus.add(newStatus); |
| } |
| } |
| |
| public void dispose() { |
| if (targetChangeListener != null) { |
| ((IObservableSet) getTarget()) |
| .removeSetChangeListener(targetChangeListener); |
| targetChangeListener = null; |
| } |
| if (modelChangeListener != null) { |
| ((IObservableSet) getModel()) |
| .removeSetChangeListener(modelChangeListener); |
| modelChangeListener = null; |
| } |
| super.dispose(); |
| } |
| } |