RegisterNodeCommand.java

/*
 * Copyright 2016 Red Hat, Inc. and/or its affiliates.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *  
 *     http://www.apache.org/licenses/LICENSE-2.0
 *  
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.kie.workbench.common.stunner.core.graph.command.impl;

import java.util.Collection;
import java.util.Optional;

import org.jboss.errai.common.client.api.annotations.MapsTo;
import org.jboss.errai.common.client.api.annotations.Portable;
import org.kie.workbench.common.stunner.core.command.CommandResult;
import org.kie.workbench.common.stunner.core.graph.Graph;
import org.kie.workbench.common.stunner.core.graph.Node;
import org.kie.workbench.common.stunner.core.graph.command.GraphCommandExecutionContext;
import org.kie.workbench.common.stunner.core.graph.command.GraphCommandResultBuilder;
import org.kie.workbench.common.stunner.core.rule.RuleViolation;
import org.kie.workbench.common.stunner.core.rule.context.CardinalityContext;
import org.kie.workbench.common.stunner.core.rule.context.impl.RuleContextBuilder;
import org.uberfire.commons.validation.PortablePreconditions;

/**
 * A Command to register and node into the graph storage.
 * Cardinality rule evaluations for the graph required.
 * <p>
 * This command should be used as aggregate for composite commands,
 * but it's recommended to provide on the factory only public commands
 * that do really update the graph structure:
 * - <a>org.kie.workbench.common.stunner.core.graph.command.impl.AddNodeCommand</a>
 * - <a>org.kie.workbench.common.stunner.core.graph.command.impl.AddChildNodeCommand</a>
 * - <a>org.kie.workbench.common.stunner.core.graph.command.impl.AddDockedNodeCommand</a>
 */
@Portable
public class RegisterNodeCommand extends AbstractGraphCommand {

    private final Node candidate;

    public RegisterNodeCommand(final @MapsTo("candidate") Node candidate) {
        this.candidate = PortablePreconditions.checkNotNull("candidate",
                                                            candidate);
    }

    @Override
    @SuppressWarnings("unchecked")
    public CommandResult<RuleViolation> execute(final GraphCommandExecutionContext context) {
        final CommandResult<RuleViolation> results = allow(context);
        if (!results.getType().equals(CommandResult.Type.ERROR)) {
            final Graph graph = getGraph(context);
            graph.addNode(candidate);
            getMutableIndex(context).addNode(candidate);
        }
        return results;
    }

    @SuppressWarnings("unchecked")
    protected CommandResult<RuleViolation> check(final GraphCommandExecutionContext context) {
        final Graph graph = getGraph(context);
        final Collection<RuleViolation> cardinalityRuleViolations =
                doEvaluate(context,
                           RuleContextBuilder.GraphContexts.cardinality(graph,
                                                                        Optional.of(getCandidate()),
                                                                        Optional.of(CardinalityContext.Operation.ADD)));
        return new GraphCommandResultBuilder(cardinalityRuleViolations).build();
    }

    @Override
    @SuppressWarnings("unchecked")
    public CommandResult<RuleViolation> undo(final GraphCommandExecutionContext context) {
        final DeregisterNodeCommand undoCommand = new DeregisterNodeCommand(candidate);
        return undoCommand.execute(context);
    }

    public Node getCandidate() {
        return candidate;
    }

    @Override
    public String toString() {
        return "RegisterNodeCommand [candidate=" + candidate.getUUID() + "]";
    }
}