CombinedClassDescriptionRepository.java

/*******************************************************************************
 * Copyright (c) 1998, 2015 Oracle and/or its affiliates. All rights reserved.
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
 * which accompanies this distribution.
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *     Oracle - initial API and implementation from Oracle TopLink
******************************************************************************/
package org.eclipse.persistence.tools.workbench.mappingsplugin.ui.meta;

import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;

import org.eclipse.persistence.tools.workbench.framework.ui.chooser.ClassDescriptionRepository;
import org.eclipse.persistence.tools.workbench.mappingsmodel.meta.MWClassRepository;
import org.eclipse.persistence.tools.workbench.mappingsmodel.spi.meta.ClassDescription;
import org.eclipse.persistence.tools.workbench.utility.filters.Filter;
import org.eclipse.persistence.tools.workbench.utility.iterators.FilteringIterator;


/**
 * The "combined" class description repository wraps the MW class repository
 * and returns a combination of the "external" types and the new
 * "internal" types.
 * The UI can use this in conjunction with ClassDescriptionAdapter.
 */
public class CombinedClassDescriptionRepository
    implements ClassDescriptionRepository
{
    protected MWClassRepository repository;
    protected Filter typeNameFilter;
    protected boolean returnsDuplicateClassNames;
    protected Set typeNames;


    // ********** constructors **********

    /**
     * Wrap the specified repository, filtering its combined types.
     * Duplicate types will be filtered out.
     */
    public CombinedClassDescriptionRepository(MWClassRepository repository, Filter typeNameFilter) {
        super();
        this.repository = repository;
        this.typeNameFilter = typeNameFilter;
        this.returnsDuplicateClassNames = false;
    }

    /**
     * Wrap the specified repository, returning all of its combined types.
     * Duplicate types will be filtered out.
     */
    public CombinedClassDescriptionRepository(MWClassRepository repository) {
        this(repository, Filter.NULL_INSTANCE);
    }


    // ********** ClassDescriptionRepository implementation **********

    /**
     * Refresh the repository's "external" types, the "internal" types do
     * not need to be refreshed.
     * @see org.eclipse.persistence.tools.workbench.framework.ui.chooser.ClassDescriptionRepository#refreshClassDescriptions()
     */
    public void refreshClassDescriptions() {
        this.typeNames = null;
        this.repository.refreshExternalClassDescriptions();
    }

    /**
     * Filter the repository's combined types.
     * @see org.eclipse.persistence.tools.workbench.framework.ui.chooser.ClassDescriptionRepository#classDescriptions()
     */
    public Iterator classDescriptions() {
        return this.filteredCombinedTypes(this.repository.combinedTypes());
    }


    // ********** public API **********

    /**
     * Set whether the repository will return duplicate class names.
     * The default is false. Set to true if you are going to refresh
     * the class and want to allow the user to select which version
     * of the class from the classpath to refresh.
     */
    public void setReturnsDuplicateClassNames(boolean returnsDuplicateClassNames) {
        this.returnsDuplicateClassNames = returnsDuplicateClassNames;
    }

    /**
     * Return whether the repository will return duplicate class names.
     * The default is false.
     */
    public boolean returnsDuplicateClassNames() {
        return this.returnsDuplicateClassNames;
    }


    // ********** filtering **********

    /**
     * Filter the original list using the client-supplied filter and an internal
     * filter for duplicates.
     */
    protected Iterator filteredCombinedTypes(Iterator combinedTypes) {
        return new FilteringIterator(combinedTypes) {
            protected boolean accept(Object o) {
                return CombinedClassDescriptionRepository.this.accept(((ClassDescription) o).getName());
            }
        };
    }

    protected boolean accept(String typeName) {
        return this.typeNameFilter.accept(typeName) && this.acceptDuplicate(typeName);
    }

    /**
     * check for duplicates, if appropriate
     */
    protected boolean acceptDuplicate(String typeName) {
        if (this.returnsDuplicateClassNames) {
            return true;
        }
        if (this.typeNames == null) {
            this.typeNames = new HashSet(10000);    // this will be big...
        }
        // @see java.util.Set#add(Object)
        return this.typeNames.add(typeName);
    }

}