DelegateCommandManager.java

/*
 * Copyright 2017 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.command;

public abstract class DelegateCommandManager<C, V> implements CommandManager<C, V> {

    protected abstract CommandManager<C, V> getDelegate();

    @Override
    public CommandResult<V> allow(final C context,
                                  final Command<C, V> command) {
        if (null != getDelegate()) {
            final CommandResult<V> r = getDelegate().allow(context,
                                                           command);
            postAllow(context,
                      command,
                      r);
            return r;
        }
        return null;
    }

    protected void postAllow(final C context,
                             final Command<C, V> command,
                             final CommandResult<V> result) {
    }

    @Override
    public CommandResult<V> execute(final C context,
                                    final Command<C, V> command) {
        if (null != getDelegate()) {
            final CommandResult<V> r = getDelegate().execute(context,
                                                             command);
            postExecute(context,
                        command,
                        r);
            return r;
        }
        return null;
    }

    protected void postExecute(final C context,
                               final Command<C, V> command,
                               final CommandResult<V> result) {
    }

    @Override
    public CommandResult<V> undo(final C context,
                                 final Command<C, V> command) {
        if (null != getDelegate()) {
            final CommandResult<V> r = getDelegate().undo(context,
                                                          command);
            postUndo(context,
                     command,
                     r);
            return r;
        }
        return null;
    }

    protected void postUndo(final C context,
                            final Command<C, V> command,
                            final CommandResult<V> result) {
    }
}