Copyright (c) 2003, 2018 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2003, 2018 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.debug.core.sourcelookup.containers;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.MultiStatus;
import org.eclipse.debug.core.DebugPlugin;
import org.eclipse.debug.core.sourcelookup.ISourceContainer;
import org.eclipse.debug.internal.core.sourcelookup.SourceLookupMessages;

A source container of source containers.

Clients implementing composite source containers should subclass
this class.

Since:
3.0/**
 * A source container of source containers.
 * <p>
 * Clients implementing composite source containers should subclass
 * this class.
 * </p>
 * @since 3.0
 */
public abstract class CompositeSourceContainer extends AbstractSourceContainer {

	private ISourceContainer[] fContainers;

	@Override
	public boolean isComposite() {
		return true;
	}

	@Override
	public Object[] findSourceElements(String name) throws CoreException {
		return findSourceElements(name, getSourceContainers());
	}

	
Returns a collection of source elements in the given containers corresponding to
the given name. Returns an empty collection if no source elements are found.
This source container's source lookup director specifies if duplicate
source elements should be searched for, via isFindDuplicates().
When false the returned collection should contain at most one
source element. If this is a composite container, the containers contained
by this container are also searched.

The format of the given name is implementation specific but generally conforms
to the format of a file name. If a source container does not recognize the
name format provided, an empty collection should be returned. A source container
may or may not require names to be fully qualified (i.e. be qualified with directory
names).

Params:
name – the name of the source element to search for
containers – the containers to search
Throws:
CoreException – if an exception occurs while searching for source elements
Returns:
a collection of source elements corresponding to the given name/**
	 * Returns a collection of source elements in the given containers corresponding to
	 * the given name. Returns an empty collection if no source elements are found.
	 * This source container's source lookup director specifies if duplicate
	 * source elements should be searched for, via <code>isFindDuplicates()</code>.
	 * When <code>false</code> the returned collection should contain at most one
	 * source element. If this is a composite container, the containers contained
	 * by this container are also searched.
	 * <p>
	 * The format of the given name is implementation specific but generally conforms
	 * to the format of a file name. If a source container does not recognize the
	 * name format provided, an empty collection should be returned. A source container
	 * may or may not require names to be fully qualified (i.e. be qualified with directory
	 * names).
	 * </p>
	 * @param name the name of the source element to search for
	 * @param containers the containers to search
	 * @return a collection of source elements corresponding to the given name
	 * @exception CoreException if an exception occurs while searching for source elements
	 */
	protected Object[] findSourceElements(String name, ISourceContainer[] containers) throws CoreException {
		List<Object> results = null;
		CoreException single = null;
		MultiStatus multiStatus = null;
		if (isFindDuplicates()) {
			results = new ArrayList<>();
		}
		for (ISourceContainer container : containers) {
			try {
				Object[] objects = container.findSourceElements(name);
				if (objects.length > 0) {
					//it will only not be null when we care about duplicates
					//saves the computation in isFindDuplicates()
					if (results != null) {
						Collections.addAll(results, objects);
					} else {
						if (objects.length == 1) {
							return objects;
						}
						return new Object[]{objects[0]};
					}
				}
			} catch (CoreException e) {
				if (single == null) {
					single = e;
				} else if (multiStatus == null) {
					multiStatus = new MultiStatus(DebugPlugin.getUniqueIdentifier(), DebugPlugin.ERROR, new IStatus[]{single.getStatus()}, SourceLookupMessages.Source_Lookup_Error, null);
					multiStatus.add(e.getStatus());
				} else {
					multiStatus.add(e.getStatus());
				}
			}
		}
		if (results == null) {
			if (multiStatus != null) {
				throw new CoreException(multiStatus);
			} else if (single != null) {
				throw single;
			}
			return EMPTY;
		}
		return results.toArray();
	}

	
Creates the source containers in this composite container.
Subclasses should override this methods.
Throws:
CoreException – if unable to create the containers
Returns:
the array of ISourceContainers/**
	 * Creates the source containers in this composite container.
	 * Subclasses should override this methods.
	 * @return the array of {@link ISourceContainer}s
	 *
	 * @throws CoreException if unable to create the containers
	 */
	protected abstract ISourceContainer[] createSourceContainers() throws CoreException;

	@Override
	public synchronized ISourceContainer[] getSourceContainers() throws CoreException {
		if (fContainers == null) {
			fContainers = createSourceContainers();
			for (ISourceContainer container : fContainers) {
				container.init(getDirector());
			}
		}
		return fContainers;
	}

	@Override
	public void dispose() {
		super.dispose();
		if (fContainers != null) {
			for (ISourceContainer container : fContainers) {
				container.dispose();
			}
		}
		fContainers = null;
	}
}