CreateMultiOperator.java

/**
 * Copyright (c) 2014 - 2017 Frank Appel
 * 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:
 *   Frank Appel - initial API and implementation
 */
package com.codeaffine.eclipse.core.runtime.internal;

import static com.codeaffine.eclipse.core.runtime.ExtensionExceptionHandler.DEFAULT_HANDLER;
import static com.codeaffine.eclipse.core.runtime.Predicates.alwaysTrue;
import static com.codeaffine.eclipse.core.runtime.RegistryAdapter.DEFAULT_TYPE_ATTRIBUTE;

import java.util.ArrayList;
import java.util.Collection;
import java.util.function.Predicate;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionRegistry;

import com.codeaffine.eclipse.core.runtime.ExecutableExtensionConfigurator;
import com.codeaffine.eclipse.core.runtime.ExecutableExtensionConfigurator.DefaultConfigurator;
import com.codeaffine.eclipse.core.runtime.Extension;
import com.codeaffine.eclipse.core.runtime.ExtensionExceptionHandler;
import com.codeaffine.eclipse.core.runtime.internal.Operator.CreateExecutableExtensionsOperator;

class CreateMultiOperator<T> implements CreateExecutableExtensionsOperator<T> {

  private final ExtensionCreatorFactory<T> factory;
  private final ContributionElementLoop loop;
  private final String extensionPointId;
  private final Class<T> extensionType;

  private ExtensionExceptionHandler exceptionHandler;
  private ExecutableExtensionConfigurator<T> configurator;
  private Predicate<Extension> predicate;
  private String typeAttribute;

  CreateMultiOperator( IExtensionRegistry registry, String extensionPointId , Class<T> extensionType ) {
    this.configurator = new DefaultConfigurator<T>();
    this.typeAttribute = DEFAULT_TYPE_ATTRIBUTE;
    this.exceptionHandler = DEFAULT_HANDLER;
    this.predicate = alwaysTrue();
    this.extensionPointId = extensionPointId;
    this.factory = new ExtensionCreatorFactory<T>();
    this.loop = new ContributionElementLoop( registry );
    this.extensionType = extensionType;
  }

  @Override
  public void setTypeAttribute( String typeAttribute ) {
    this.typeAttribute = typeAttribute;
  }

  @Override
  public void setPredicate( Predicate<Extension> predicate ) {
    this.predicate = predicate;
  }

  @Override
  public void setConfigurator( ExecutableExtensionConfigurator<T> configurator ) {
    this.configurator = configurator;
  }

  @Override
  public void setExceptionHandler( ExtensionExceptionHandler exceptionHandler ) {
    this.exceptionHandler = exceptionHandler;
  }

  @Override
  public Collection<T> create() {
    Collection<T> result = new ArrayList<T>();
    loop.forEach( extensionPointId, predicate, element -> collectExtension( result, element ) );
    return result;
  }

  private void collectExtension( Collection<T> extensions, IConfigurationElement element ) {
    T extension = newCreator( element ).create();
    if( extension != null ) {
      extensions.add( extension );
    }
  }

  private ExtensionCreator<T> newCreator( IConfigurationElement element ) {
    return factory.create( element, extensionType, exceptionHandler, configurator, typeAttribute );
  }
}