it.tidalwave.bluebill.mobile.role.util.PredicateCapabilityProvider Maven / Gradle / Ivy

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/***********************************************************************************************************************
 *
 * blueBill Mobile - Android - open source birding
 * Copyright (C) 2009-2011 by Tidalwave s.a.s. (http://www.tidalwave.it)
 *
 ***********************************************************************************************************************
 *
 * 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.
 *
 ***********************************************************************************************************************
 *
 * WWW: http://bluebill.tidalwave.it/mobile
 * SCM: https://java.net/hg/bluebill-mobile~android-src
 *
 **********************************************************************************************************************/
package it.tidalwave.bluebill.mobile.role.util;

import javax.annotation.Nonnull;
import java.util.Collection;
import java.util.Collections;
import org.openide.util.Lookup;
import org.openide.util.Lookup.Template;
import it.tidalwave.netbeans.util.LazyLookup;
import it.tidalwave.netbeans.capabilitiesprovider.CapabilitiesProvider;
import it.tidalwave.bluebill.mobile.role.util.RoleRegister.Predicate;
import lombok.Getter;
import lombok.RequiredArgsConstructor;

/***********************************************************************************************************************
 *
 * @author  Fabrizio Giudici
 * @version $Id$
 *
 **********************************************************************************************************************/
@RequiredArgsConstructor
public class PredicateCapabilityProvider implements CapabilitiesProvider
  {
    @Nonnull @Getter
    private final Class managedClass;

    @Nonnull 
    private final Object role;
    
    @Nonnull
    private final Predicate predicate;
    
    @Nonnull
    public Collection createCapabilities (final @Nonnull Object owner) 
      {
        return Collections.emptyList();
      }

    // We can't just directly create the capability as we want to inspect the object's Lookup, and this operation
    // can't be done in a CapabilityProvider, since the Lookup has not been instantiated yet. So we're using a lazy
    // Lookup that will postpone the operation.                
    @Nonnull
    public Collection createLookups (final @Nonnull Object owner) 
      {
        return Collections.singletonList(new LazyLookup() 
          {
            @Override @Nonnull
            protected Collection computeInstances (final @Nonnull Template template) 
              {
                // First test type, to avoid useless calls to the predicate
                return (template.getType().isAssignableFrom(role.getClass()) && predicate.apply(owner)) 
                                ? Collections.singletonList(role) 
                                : Collections.emptyList();            
              }
          });
      }
  }