| /******************************************************************************* |
| * Copyright (c) 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 |
| ******************************************************************************/ |
| |
| package org.eclipse.core.databinding; |
| |
| import java.util.Collections; |
| |
| import org.eclipse.core.databinding.observable.Diffs; |
| import org.eclipse.core.databinding.observable.list.IListChangeListener; |
| import org.eclipse.core.databinding.observable.list.IObservableList; |
| import org.eclipse.core.databinding.observable.list.ListChangeEvent; |
| import org.eclipse.core.databinding.observable.list.ListDiff; |
| import org.eclipse.core.databinding.observable.list.ListDiffEntry; |
| 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 1.0 |
| * |
| */ |
| public class ListBinding extends Binding { |
| |
| private UpdateListStrategy targetToModel; |
| private UpdateListStrategy modelToTarget; |
| private IObservableValue validationStatusObservable; |
| private boolean updatingTarget; |
| private boolean updatingModel; |
| |
| private IListChangeListener targetChangeListener = new IListChangeListener() { |
| public void handleListChange(ListChangeEvent event) { |
| if (!updatingTarget) { |
| doUpdate((IObservableList) getTarget(), |
| (IObservableList) getModel(), event.diff, |
| targetToModel, false, false); |
| } |
| } |
| }; |
| private IListChangeListener modelChangeListener = new IListChangeListener() { |
| public void handleListChange(ListChangeEvent event) { |
| if (!updatingModel) { |
| doUpdate((IObservableList) getModel(), |
| (IObservableList) getTarget(), event.diff, |
| modelToTarget, false, false); |
| } |
| } |
| }; |
| |
| /** |
| * @param target |
| * @param model |
| * @param modelToTargetStrategy |
| * @param targetToModelStrategy |
| */ |
| public ListBinding(IObservableList target, IObservableList model, |
| UpdateListStrategy targetToModelStrategy, |
| UpdateListStrategy modelToTargetStrategy) { |
| super(target, model); |
| this.targetToModel = targetToModelStrategy; |
| this.modelToTarget = modelToTargetStrategy; |
| if ((targetToModel.getUpdatePolicy() & UpdateValueStrategy.POLICY_UPDATE) != 0) { |
| target.addListChangeListener(targetChangeListener); |
| } else { |
| targetChangeListener = null; |
| } |
| if ((modelToTarget.getUpdatePolicy() & UpdateValueStrategy.POLICY_UPDATE) != 0) { |
| model.addListChangeListener(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() == UpdateListStrategy.POLICY_UPDATE) { |
| updateModelToTarget(); |
| } |
| if (targetToModel.getUpdatePolicy() != UpdateListStrategy.POLICY_NEVER) { |
| validateTargetToModel(); |
| } |
| } |
| |
| public void updateModelToTarget() { |
| final IObservableList modelList = (IObservableList) getModel(); |
| modelList.getRealm().exec(new Runnable() { |
| public void run() { |
| ListDiff diff = Diffs.computeListDiff(Collections.EMPTY_LIST, |
| modelList); |
| doUpdate(modelList, (IObservableList) getTarget(), diff, |
| modelToTarget, true, true); |
| } |
| }); |
| } |
| |
| public void updateTargetToModel() { |
| final IObservableList targetList = (IObservableList) getTarget(); |
| targetList.getRealm().exec(new Runnable() { |
| public void run() { |
| ListDiff diff = Diffs.computeListDiff(Collections.EMPTY_LIST, |
| targetList); |
| doUpdate(targetList, (IObservableList) getModel(), diff, |
| targetToModel, true, true); |
| } |
| }); |
| } |
| |
| public void validateModelToTarget() { |
| // nothing for now |
| } |
| |
| public void validateTargetToModel() { |
| // nothing for now |
| } |
| |
| /* |
| * This method may be moved to UpdateListStrategy in the future if clients |
| * need more control over how the two lists are kept in sync. |
| */ |
| private void doUpdate(final IObservableList source, |
| final IObservableList destination, final ListDiff diff, |
| final UpdateListStrategy updateListStrategy, |
| final boolean explicit, final boolean clearDestination) { |
| final int policy = updateListStrategy.getUpdatePolicy(); |
| if (policy != UpdateListStrategy.POLICY_NEVER) { |
| if (policy != UpdateListStrategy.POLICY_ON_REQUEST || explicit) { |
| 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(); |
| } |
| ListDiffEntry[] diffEntries = diff.getDifferences(); |
| for (int i = 0; i < diffEntries.length; i++) { |
| ListDiffEntry listDiffEntry = diffEntries[i]; |
| if (listDiffEntry.isAddition()) { |
| IStatus setterStatus = updateListStrategy |
| .doAdd( |
| destination, |
| updateListStrategy |
| .convert(listDiffEntry |
| .getElement()), |
| listDiffEntry.getPosition()); |
| |
| mergeStatus(multiStatus, setterStatus); |
| // TODO - at this point, the two lists |
| // will be out of sync if an error occurred... |
| } else { |
| IStatus setterStatus = updateListStrategy |
| .doRemove(destination, |
| listDiffEntry.getPosition()); |
| |
| mergeStatus(multiStatus, setterStatus); |
| // TODO - at this point, the two lists |
| // 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) { |
| ((IObservableList)getTarget()).removeListChangeListener(targetChangeListener); |
| targetChangeListener = null; |
| } |
| if (modelChangeListener != null) { |
| ((IObservableList)getModel()).removeListChangeListener(modelChangeListener); |
| modelChangeListener = null; |
| } |
| super.dispose(); |
| } |
| } |