AbstractGraphCompositeCommand.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 org.kie.workbench.common.stunner.core.command.Command;
import org.kie.workbench.common.stunner.core.command.CommandResult;
import org.kie.workbench.common.stunner.core.command.exception.BadCommandArgumentsException;
import org.kie.workbench.common.stunner.core.command.impl.AbstractCompositeCommand;
import org.kie.workbench.common.stunner.core.graph.Edge;
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.EmptyRulesCommandExecutionContext;
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.graph.content.view.View;
import org.kie.workbench.common.stunner.core.graph.processing.index.MutableIndex;
import org.kie.workbench.common.stunner.core.rule.RuleViolation;

public abstract class AbstractGraphCompositeCommand extends AbstractCompositeCommand<GraphCommandExecutionContext, RuleViolation> {

    /**
     * Each child command operation can be done by:
     * - Each child command check rules
     * - The composite command implementation will check the necessary rules in a single run, no need
     * to evaluate rules on each child command.
     */
    protected abstract boolean delegateRulesContextToChildren();

    @Override
    protected CommandResult<RuleViolation> doUndo(final GraphCommandExecutionContext context,
                                                  final Command<GraphCommandExecutionContext, RuleViolation> command) {
        return command.undo(delegateRulesContextToChildren() ? context : buildEmptyExecutionContext(context));
    }

    @Override
    protected CommandResult<RuleViolation> doExecute(final GraphCommandExecutionContext context,
                                                     final Command<GraphCommandExecutionContext, RuleViolation> command) {
        return command.execute(delegateRulesContextToChildren() ? context : buildEmptyExecutionContext(context));
    }

    @Override
    protected CommandResult<RuleViolation> doAllow(final GraphCommandExecutionContext context,
                                                   final Command<GraphCommandExecutionContext, RuleViolation> command) {
        // Check if rules are present.
        if (null == context.getRuleManager()) {
            return GraphCommandResultBuilder.SUCCESS;
        }
        return command.allow(context);
    }

    @SuppressWarnings("unchecked")
    protected MutableIndex<Node, Edge> getMutableIndex(final GraphCommandExecutionContext context) {
        return (MutableIndex<Node, Edge>) context.getGraphIndex();
    }

    @SuppressWarnings("unchecked")
    protected Graph<?, Node> getGraph(final GraphCommandExecutionContext context) {
        return (Graph<?, Node>) context.getGraphIndex().getGraph();
    }

    @SuppressWarnings("unchecked")
    protected Node<?, Edge> getNode(final GraphCommandExecutionContext context,
                                    final String uuid) {
        return context.getGraphIndex().getNode(uuid);
    }

    @SuppressWarnings("unchecked")
    protected Edge<? extends View, Node> getViewEdge(final GraphCommandExecutionContext context,
                                                     final String uuid) {
        return context.getGraphIndex().getEdge(uuid);
    }

    protected Node<?, Edge> checkNodeNotNull(final GraphCommandExecutionContext context,
                                             final String uuid) {
        final Node<?, Edge> e = getNode(context,
                                        uuid);
        if (null == e) {
            throw new BadCommandArgumentsException(this,
                                                   uuid,
                                                   "Node not found for [" + uuid + "].");
        }
        return e;
    }

    private EmptyRulesCommandExecutionContext buildEmptyExecutionContext(final GraphCommandExecutionContext context) {
        return new EmptyRulesCommandExecutionContext(context.getDefinitionManager(),
                                                     context.getFactoryManager(),
                                                     context.getRuleManager(),
                                                     context.getGraphIndex());
    }
}