/*******************************************************************************
* Copyright (c) 2005, 2016 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
* Matt Carter - bug 182822
* Boris Bokowski - bug 218269
* Matthew Hall - bugs 218269, 146397, 249526, 267451
* Simon Scholz <simon.scholz@vogella.com> - Bug 489098
*******************************************************************************/
package org.eclipse.core.databinding;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import org.eclipse.core.databinding.observable.IObservableCollection;
import org.eclipse.core.databinding.observable.Realm;
import org.eclipse.core.databinding.observable.value.ComputedValue;
import org.eclipse.core.databinding.util.Policy;
import org.eclipse.core.internal.databinding.BindingMessages;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.MultiStatus;
import org.eclipse.core.runtime.Status;
/**
* This class can be used to aggregate status values from a data binding context
* into a single status value. Instances of this class can be used as an
* observable value with a value type of {@link IStatus}, or the static methods
* can be called directly if an aggregated status result is only needed once.
*
* @since 1.0
*
*/
public final class AggregateValidationStatus extends ComputedValue<IStatus> {
/**
* Constant denoting an aggregation strategy that merges multiple non-OK
* status objects in a {@link MultiStatus}. Returns an OK status result if
* all statuses from the given validation status providers are the an OK
* status. Returns a single status if there is only one non-OK status.
*
* @see #getStatusMerged(Collection)
*/
public static final int MERGED = 1;
/**
* Constant denoting an aggregation strategy that always returns the most
* severe status from the given validation status providers. If there is
* more than one status at the same severity level, it picks the first one
* it encounters.
*
* @see #getStatusMaxSeverity(Collection)
*/
public static final int MAX_SEVERITY = 2;
private int strategy;
private IObservableCollection validationStatusProviders;
/**
* Creates a new aggregate validation status observable for the given data
* binding context.
*
* @param dbc
* a data binding context
* @param strategy
* a strategy constant, one of {@link #MERGED} or
* {@link #MAX_SEVERITY}.
* @since 1.1
*/
public AggregateValidationStatus(DataBindingContext dbc, int strategy) {
this(dbc.getValidationRealm(), dbc.getValidationStatusProviders(),
strategy);
}
/**
* @param validationStatusProviders
* an observable collection containing elements of type
* {@link ValidationStatusProvider}
* @param strategy
* a strategy constant, one of {@link #MERGED} or
* {@link #MAX_SEVERITY}.
* @see DataBindingContext#getValidationStatusProviders()
*/
public AggregateValidationStatus(
final IObservableCollection validationStatusProviders, int strategy) {
this(Realm.getDefault(), validationStatusProviders, strategy);
}
/**
* @param realm
* Realm
* @param validationStatusProviders
* an observable collection containing elements of type
* {@link ValidationStatusProvider}
* @param strategy
* a strategy constant, one of {@link #MERGED} or
* {@link #MAX_SEVERITY}.
* @see DataBindingContext#getValidationStatusProviders()
* @since 1.1
*/
public AggregateValidationStatus(final Realm realm,
final IObservableCollection validationStatusProviders, int strategy) {
super(realm, IStatus.class);
this.validationStatusProviders = validationStatusProviders;
this.strategy = strategy;
}
@Override
protected IStatus calculate() {
IStatus result;
if (strategy == MERGED) {
result = getStatusMerged(validationStatusProviders);
} else {
result = getStatusMaxSeverity(validationStatusProviders);
}
return result;
}
/**
* Returns a status object that merges multiple non-OK status objects in a
* {@link MultiStatus}. Returns an OK status result if all statuses from the
* given validation status providers are the an OK status. Returns a single
* status if there is only one non-OK status.
*
* @param validationStatusProviders
* a collection of validation status providers
* @return a merged status
*/
public static IStatus getStatusMerged(Collection validationStatusProviders) {
List statuses = new ArrayList();
for (Iterator it = validationStatusProviders.iterator(); it.hasNext();) {
ValidationStatusProvider validationStatusProvider = (ValidationStatusProvider) it
.next();
IStatus status = (IStatus) validationStatusProvider
.getValidationStatus().getValue();
if (!status.isOK()) {
statuses.add(status);
}
}
if (statuses.size() == 1) {
return (IStatus) statuses.get(0);
}
if (!statuses.isEmpty()) {
MultiStatus result = new MultiStatus(Policy.JFACE_DATABINDING, 0,
BindingMessages
.getString(BindingMessages.MULTIPLE_PROBLEMS), null);
for (Iterator it = statuses.iterator(); it.hasNext();) {
IStatus status = (IStatus) it.next();
result.merge(status);
}
return result;
}
return Status.OK_STATUS;
}
/**
* Returns a status that always returns the most severe status from the
* given validation status providers. If there is more than one status at
* the same severity level, it picks the first one it encounters.
*
* @param validationStatusProviders
* a collection of validation status providers
* @return a single status reflecting the most severe status from the given
* validation status providers
*/
public static IStatus getStatusMaxSeverity(
Collection validationStatusProviders) {
int maxSeverity = IStatus.OK;
IStatus maxStatus = Status.OK_STATUS;
for (Iterator it = validationStatusProviders.iterator(); it.hasNext();) {
ValidationStatusProvider validationStatusProvider = (ValidationStatusProvider) it
.next();
IStatus status = (IStatus) validationStatusProvider
.getValidationStatus().getValue();
if (status.getSeverity() > maxSeverity) {
maxSeverity = status.getSeverity();
maxStatus = status;
}
}
return maxStatus;
}
}