/*******************************************************************************
 * Copyright (c) 2000, 2008 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.core.resources;

import java.util.Map;
import org.eclipse.core.runtime.*;
import org.eclipse.core.runtime.content.IContentTypeMatcher;

/**
 * A project is a type of resource which groups resources
 * into buildable, reusable units.  
 * <p>
 * Features of projects include:
 * <ul>
 * <li>A project collects together a set of files and folders.</li>
 * <li>A project's location controls where the project's resources are 
 *		stored in the local file system.</li>
 * <li>A project's build spec controls how building is done on the project.</li>
 * <li>A project can carry session and persistent properties.</li>
 * <li>A project can be open or closed; a closed project is
 * 		passive and has a minimal in-memory footprint.</li>
 * <li>A project can carry references to other projects.</li>
 * <li>A project can have one or more project natures.</li>
 * </ul>
 * </p>
 * <p>
 * Projects implement the <code>IAdaptable</code> interface;
 * extensions are managed by the platform's adapter manager.
 * </p>
 *
 * @see Platform#getAdapterManager()
 * @noimplement This interface is not intended to be implemented by clients.
 */
public interface IProject extends IContainer, IAdaptable {
	/**
	 * Invokes the <code>build</code> method of the specified builder 
	 * for this project. Does nothing if this project is closed.  If this project
	 * has multiple builders on its build spec matching the given name, only
	 * the first matching builder will be run.
	 * <p>
	 * The builder name is declared in the extension that plugs in
	 * to the standard <code>org.eclipse.core.resources.builders</code> 
	 * extension point.  The arguments are builder specific.
	 * </p>
	 * <p>
	 * This method may change resources; these changes will be reported
	 * in a subsequent resource change event.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor.
	 * </p>
	 *
	 * @param kind the kind of build being requested. Valid values are:
	 *	<ul>
	 * <li>{@link IncrementalProjectBuilder#FULL_BUILD}- indicates a full build.</li>
	 * <li>{@link IncrementalProjectBuilder#INCREMENTAL_BUILD}- indicates a incremental build.</li>
	 * <li>{@link IncrementalProjectBuilder#CLEAN_BUILD}- indicates a clean request.  Clean does
	 * not actually build anything, but rather discards all problems and build states.</li>
	 *	</ul>
	 * @param builderName the name of the builder
	 * @param args a table of builder-specific arguments keyed by argument name
	 *		(key type: <code>String</code>, value type: <code>String</code>);
	 *		<code>null</code> is equivalent to an empty map
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *		reporting is not desired
	 * @exception CoreException if the build fails.
	 *		The status contained in the exception may be a generic {@link IResourceStatus#BUILD_FAILED}
	 *		code, but it could also be any other status code; it might
	 *		also be a {@link MultiStatus}.
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 * 
	 * @see IProjectDescription
	 * @see IncrementalProjectBuilder#build(int, Map, IProgressMonitor)
	 * @see IncrementalProjectBuilder#FULL_BUILD
	 * @see IncrementalProjectBuilder#INCREMENTAL_BUILD
	 * @see IncrementalProjectBuilder#CLEAN_BUILD
	 * @see IResourceRuleFactory#buildRule()
	 */
	public void build(int kind, String builderName, Map args, IProgressMonitor monitor) throws CoreException;

	/** 
	 * Builds this project. Does nothing if the project is closed.
	 * <p>
	 * Building a project involves executing the commands found
	 * in this project's build spec.
	 * </p>
	 * <p>
	 * This method may change resources; these changes will be reported
	 * in a subsequent resource change event.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor.
	 * </p>
	 *
	 * @param kind the kind of build being requested. Valid values are:
	 *		<ul>
	 *		<li> <code>IncrementalProjectBuilder.FULL_BUILD</code> - indicates a full build.</li>
	 *		<li> <code>IncrementalProjectBuilder.INCREMENTAL_BUILD</code> - indicates an incremental build.</li>
	 * 		<li><code>CLEAN_BUILD</code>- indicates a clean request. Clean does
	 * 		not actually build anything, but rather discards all problems and build states.
	 *		</ul>
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *		reporting is not desired
	 * @exception CoreException if the build fails.
	 *		The status contained in the exception may be a generic <code>BUILD_FAILED</code>
	 *		code, but it could also be any other status code; it might
	 *		also be a multi-status.
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 *
	 * @see IProjectDescription
	 * @see IncrementalProjectBuilder#FULL_BUILD
	 * @see IncrementalProjectBuilder#INCREMENTAL_BUILD
	 * @see IResourceRuleFactory#buildRule()
	 */
	public void build(int kind, IProgressMonitor monitor) throws CoreException;

	/**
	 * Closes this project.  The project need not be open.  Closing
	 * a closed project does nothing.
	 * <p>
	 * Closing a project involves ensuring that all important project-related
	 * state is safely stored on disk, and then discarding the in-memory
	 * representation of its resources and other volatile state, 
	 * including session properties.
	 * After this method, the project continues to exist in the workspace
	 * but its member resources (and their members, etc.) do not.  
	 * A closed project can later be re-opened.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event that includes
	 * an indication that this project has been closed and its members
	 * have been removed.  
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor.
	 * </p>
	 *
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *		reporting is not desired
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This resource does not exist.</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 * @see #open(IProgressMonitor)
	 * @see #isOpen()
	 * @see IResourceRuleFactory#modifyRule(IResource)
	 */
	public void close(IProgressMonitor monitor) throws CoreException;

	/**
	 * Creates a new project resource in the workspace using the given project
	 * description. Upon successful completion, the project will exist but be closed.
	 * <p>
	 * Newly created projects have no session or persistent properties. 
	 * </p>
	 * <p>
	 * If the project content area given in the project description does not 
	 * contain a project description file, a project description file is written
	 * in the project content area with the natures, build spec, comment, and 
	 * referenced projects as specified in the given project description.
	 * If there is an existing project description file, it is not overwritten.  In either
	 * case, this method does not cause natures to be configured.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that the project has been added to the workspace.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 *
	 * @param description the project description
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project already exists in the workspace.</li>
	 * <li> The name of this resource is not valid (according to 
	 *    <code>IWorkspace.validateName</code>).</li>
	 * <li> The project location is not valid (according to
	 *      <code>IWorkspace.validateProjectLocation</code>).</li>
	 * <li> The project description file could not be created in the project 
	 *      content area.</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 *
	 * @see IWorkspace#validateProjectLocation(IProject, IPath)
	 * @see IResourceRuleFactory#createRule(IResource)
	 */
	public void create(IProjectDescription description, IProgressMonitor monitor) throws CoreException;

	/**
	 * Creates a new project resource in the workspace with files in the default
	 * location in the local file system. Upon successful completion, the project
	 * will exist but be closed.
	 * <p>
	 * Newly created projects have no session or persistent properties. 
	 * </p>
	 * <p>
	 * If the project content area does not contain a project description file,
	 * an initial project description file is written in the project content area
	 * with the following information:
	 * <ul>
	 * <li>no references to other projects</li>
	 * <li>no natures</li>
	 * <li>an empty build spec</li>
	 * <li>an empty comment</li>
	 * </ul>
	 * If there is an existing project description file, it is not overwritten.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that this project has been added to the workspace.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 * 
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project already exists in the workspace.</li>
	 * <li> The name of this resource is not valid (according to 
	 *    <code>IWorkspace.validateName</code>).</li>
	 * <li> The project location is not valid (according to
	 *      <code>IWorkspace.validateProjectLocation</code>).</li>
	 * <li> The project description file could not be created in the project 
	 *      content area.</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 *
	 * @see IWorkspace#validateProjectLocation(IProject, IPath)
	 * @see IResourceRuleFactory#createRule(IResource)
	 */
	public void create(IProgressMonitor monitor) throws CoreException;

	/**
	 * Creates a new project resource in the workspace using the given project
	 * description. Upon successful completion, the project will exist but be closed.
	 * <p>
	 * Newly created projects have no session or persistent properties. 
	 * </p>
	 * <p>
	 * If the project content area given in the project description does not 
	 * contain a project description file, a project description file is written
	 * in the project content area with the natures, build spec, comment, and 
	 * referenced projects as specified in the given project description.
	 * If there is an existing project description file, it is not overwritten.  In either
	 * case, this method does not cause natures to be configured.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that the project has been added to the workspace.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 * <p>
	 * The {@link IResource#HIDDEN} update flag indicates that this resource
	 * should immediately be set as a hidden resource.  Specifying this flag
	 * is equivalent to atomically calling {@link IResource#setHidden(boolean)}
	 * with a value of <code>true</code> immediately after creating the resource.
	 * </p>
	 * <p>
	 * Update flags other than those listed above are ignored.
	 * </p>
	 *
	 * @param description the project description
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project already exists in the workspace.</li>
	 * <li> The name of this resource is not valid (according to 
	 *    <code>IWorkspace.validateName</code>).</li>
	 * <li> The project location is not valid (according to
	 *      <code>IWorkspace.validateProjectLocation</code>).</li>
	 * <li> The project description file could not be created in the project 
	 *      content area.</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 *
	 * @see IWorkspace#validateProjectLocation(IProject, IPath)
	 * @see IResourceRuleFactory#createRule(IResource)
	 * 
	 * @since 3.4
	 */
	public void create(IProjectDescription description, int updateFlags, IProgressMonitor monitor) throws CoreException;

	/**
	 * Deletes this project from the workspace.
	 * No action is taken if this project does not exist.
	 * <p>
	 * This is a convenience method, fully equivalent to:
	 * <pre>
	 *   delete(
	 *     (deleteContent ? IResource.ALWAYS_DELETE_PROJECT_CONTENT : IResource.NEVER_DELETE_PROJECT_CONTENT )
	 *        | (force ? FORCE : IResource.NONE),
	 *     monitor);
	 * </pre>
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor.
	 * </p>
	 *
	 * @param deleteContent a flag controlling how whether content is
	 *    aggressively deleted
	 * @param force a flag controlling whether resources that are not
	 *    in sync with the local file system will be tolerated
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project could not be deleted.</li>
	 * <li> This project's contents could not be deleted.</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 * @see IResource#delete(int, IProgressMonitor)
	 * @see #open(IProgressMonitor)
	 * @see #close(IProgressMonitor)
	 * @see IResource#delete(int,IProgressMonitor)
	 * @see IResourceRuleFactory#deleteRule(IResource)
	 */
	public void delete(boolean deleteContent, boolean force, IProgressMonitor monitor) throws CoreException;
	
	/**
	 * Returns this project's content type matcher. This content type matcher takes 
	 * project specific preferences and nature-content type associations into 
	 * account.
	 * 
	 * @return the content type matcher for this project
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project does not exist.</li>
	 * <li> This project is not open.</li>
	 * </ul>
	 * @see IContentTypeMatcher
	 * @since 3.1
	 */
	public IContentTypeMatcher getContentTypeMatcher() throws CoreException;

	/**
	 * Returns the description for this project.
	 * The returned value is a copy and cannot be used to modify 
	 * this project.  The returned value is suitable for use in creating, 
	 * copying and moving other projects.
	 *
	 * @return the description for this project
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project does not exist.</li>
	 * <li> This project is not open.</li>
	 * </ul>
	 * @see #create(IProgressMonitor)
	 * @see #create(IProjectDescription, IProgressMonitor)
	 * @see IResource#copy(IProjectDescription, int, IProgressMonitor)
	 * @see #move(IProjectDescription, boolean, IProgressMonitor) 
	 */
	public IProjectDescription getDescription() throws CoreException;

	/**
	 * Returns a handle to the file with the given name in this project.
	 * <p> 
	 * This is a resource handle operation; neither the resource nor
	 * the result need exist in the workspace.
	 * The validation check on the resource name/path is not done
	 * when the resource handle is constructed; rather, it is done
	 * automatically as the resource is created.
	 * </p>
	 *
	 * @param name the string name of the member file
	 * @return the (handle of the) member file
	 * @see #getFolder(String)
	 */
	public IFile getFile(String name);

	/**
	 * Returns a handle to the folder with the given name in this project.
	 * <p> 
	 * This is a resource handle operation; neither the container
	 * nor the result need exist in the workspace.
	 * The validation check on the resource name/path is not done
	 * when the resource handle is constructed; rather, it is done
	 * automatically as the resource is created.
	 * </p>
	 *
	 * @param name the string name of the member folder
	 * @return the (handle of the) member folder
	 * @see #getFile(String)
	 */
	public IFolder getFolder(String name);

	/** 
	 * Returns the specified project nature for this project or <code>null</code> if
	 * the project nature has not been added to this project.
	 * Clients may downcast to a more concrete type for more nature-specific methods.
	 * The documentation for a project nature specifies any such additional protocol.
	 * <p>
	 * This may cause the plug-in that provides the given nature to be activated.
	 * </p>
	 *
	 * @param natureId the fully qualified nature extension identifier, formed
	 * by combining the nature extension id with the id of the declaring plug-in.
	 * (e.g. <code>"com.example.acmeplugin.coolnature"</code>)
	 * @return the project nature object
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project does not exist.</li>
	 * <li> This project is not open.</li>
	 * <li> The project nature extension could not be found.</li>
	 * </ul>
	 */
	public IProjectNature getNature(String natureId) throws CoreException;

	/**
	 * Returns the location in the local file system of the project-specific
	 * working data area for use by the given plug-in or <code>null</code>
	 * if the project does not exist.
	 * <p>
	 * The content, structure, and management of this area is 
	 * the responsibility of the plug-in.  This area is deleted when the
	 * project is deleted.
	 * </p><p>
	 * This project needs to exist but does not need to be open.
	 * </p>
	 * @param plugin the plug-in
	 * @return a local file system path
	 * @deprecated Use <code>IProject.getWorkingLocation(plugin.getUniqueIdentifier())</code>.
	 */
	public IPath getPluginWorkingLocation(IPluginDescriptor plugin);

	/**
	 * Returns the location in the local file system of the project-specific
	 * working data area for use by the bundle/plug-in with the given identifier, 
	 * or <code>null</code> if the project does not exist.
	 * <p>
	 * The content, structure, and management of this area is 
	 * the responsibility of the bundle/plug-in.  This area is deleted when the
	 * project is deleted.
	 * </p><p>
	 * This project needs to exist but does not need to be open.
	 * </p>
	 * @param id the bundle or plug-in's identifier
	 * @return a local file system path
	 * @since 3.0
	 */
	public IPath getWorkingLocation(String id);

	/**
	 * Returns the projects referenced by this project. This includes
	 * both the static and dynamic references of this project.
	 * The returned projects need not exist in the workspace.
	 * The result will not contain duplicates. Returns an empty
	 * array if there are no referenced projects.
	 *
	 * @return a list of projects
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project does not exist.</li>
	 * <li> This project is not open.</li>
	 * </ul>
	 * @see IProjectDescription#getReferencedProjects()
	 * @see IProjectDescription#getDynamicReferences()
	 */
	public IProject[] getReferencedProjects() throws CoreException;

	/**
	 * Returns the list of all open projects which reference
	 * this project. This project may or may not exist. Returns
	 * an empty array if there are no referencing projects.
	 *
	 * @return a list of open projects referencing this project
	 */
	public IProject[] getReferencingProjects();

	/** 
	 * Returns whether the project nature specified by the given
	 * nature extension id has been added to this project. 
	 *
	 * @param natureId the nature extension identifier
	 * @return <code>true</code> if the project has the given nature 
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project does not exist.</li>
	 * <li> This project is not open.</li>
	 * </ul>
	 */
	public boolean hasNature(String natureId) throws CoreException;

	/**
	 * Returns true if the project nature specified by the given
	 * nature extension id is enabled for this project, and false otherwise.
	 * <p>
	 * <ul>Reasons for a nature not to be enabled include:
	 * <li> The nature is not available in the install.</li>
	 * <li> The nature has not been added to this project.</li>
	 * <li> The nature has a prerequisite that is not enabled
	 * 	for this project.</li>
	 * <li> The nature specifies "one-of-nature" membership in
	 * 	a set, and there is another nature on this project belonging
	 * 	to that set.</li>
	 * <li> The prerequisites for the nature form a cycle.</li>
	 * </ul>
	 * </p>
	 * @param natureId the nature extension identifier
	 * @return <code>true</code> if the given nature is enabled for this project
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project does not exist.</li>
	 * <li> This project is not open.</li>
	 * </ul>
	 * @since 2.0
	 * @see IWorkspace#validateNatureSet(String[])
	 */
	public boolean isNatureEnabled(String natureId) throws CoreException;

	/**
	 * Returns whether this project is open.
	 * <p>
	 * A project must be opened before it can be manipulated.
	 * A closed project is passive and has a minimal memory
	 * footprint; a closed project has no members.
	 * </p>
	 *
	 * @return <code>true</code> if this project is open, <code>false</code> if
	 *		this project is closed or does not exist
	 * @see #open(IProgressMonitor)
	 * @see #close(IProgressMonitor)
	 */
	public boolean isOpen();

	/**
	 * Renames this project so that it is located at the name in 
	 * the given description.  
	 * <p>
	 * This is a convenience method, fully equivalent to:
	 * <pre>
	 *   move(description, (force ? FORCE : IResource.NONE), monitor);
	 * </pre>
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event that will include 
	 * an indication that the resource has been removed from its parent
	 * and that a corresponding resource has been added to its new parent.
	 * Additional information provided with resource delta shows that these
	 * additions and removals are related.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 *
	 * @param description the description for the destination project
	 * @param force a flag controlling whether resources that are not
	 *    in sync with the local file system will be tolerated
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @exception CoreException if this resource could not be moved. Reasons include:
	 * <ul>
	 * <li> This resource is not accessible.</li>
	 * <li> This resource or one of its descendents is not local.</li>
	 * <li> This resource or one of its descendents is out of sync with the local file system
	 *      and <code>force</code> is <code>false</code>.</li>
	 * <li> The workspace and the local file system are out of sync
	 *      at the destination resource or one of its descendents.</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 * @see IResourceDelta#getFlags()
	 * @see IResource#move(IProjectDescription,int,IProgressMonitor)
	 * @see IResourceRuleFactory#moveRule(IResource, IResource)
	 */
	public void move(IProjectDescription description, boolean force, IProgressMonitor monitor) throws CoreException;

	/**
	 * Opens this project.  No action is taken if the project is already open.
	 * <p>
	 * Opening a project constructs an in-memory representation 
	 * of its resources from information stored on disk.
	 * </p>
	 * <p>
	 * The <code>BACKGROUND_REFRESH</code> update flag controls how
	 * this method behaves when a project is opened for the first time on a location
	 * that has existing resources on disk.  If this flag is specified, resources on disk
	 * will be added to the project in the background after this method returns.
	 * Child resources of the project may not be available until this background
	 * refresh completes. If this flag is not specified, resources on disk are added 
	 * to the project in the foreground before this method returns.
	 * </p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event that includes
	 * an indication that the project has been opened and its resources
	 * have been added to the tree.  If the <code>BACKGROUND_REFRESH</code>
	 * update flag is specified, multiple resource change events may occur as
	 * resources on disk are discovered and added to the tree.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor.
	 * </p>
	 *
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 * @see #close(IProgressMonitor)
	 * @see IResource#BACKGROUND_REFRESH
	 * @see IResourceRuleFactory#modifyRule(IResource)
	 * @since 3.1
	 */
	public void open(int updateFlags, IProgressMonitor monitor) throws CoreException;
	
	/**
	 * Opens this project.  No action is taken if the project is already open.
	 * <p>
	 * This is a convenience method, fully equivalent to 
	 * <code>open(IResource.NONE, monitor)</code>.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event that includes
	 * an indication that the project has been opened and its resources
	 * have been added to the tree.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor.
	 * </p>
	 *
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 * @see #close(IProgressMonitor)
	 * @see IResourceRuleFactory#modifyRule(IResource)
	 */
	public void open(IProgressMonitor monitor) throws CoreException;

	/**
	 * Changes this project resource to match the given project
	 * description. This project should exist and be open.
	 * <p>
	 * This is a convenience method, fully equivalent to:
	 * <pre>
	 *   setDescription(description, KEEP_HISTORY, monitor);
	 * </pre>
	 * </p>
	 * <p>
	 * This method requires the {@link IWorkspaceRoot} scheduling rule.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that the project's content has changed.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 *
	 * @param description the project description
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project does not exist in the workspace.</li>
	 * <li> This project is not open.</li>
	 * <li> The location in the local file system corresponding to the project
	 *   description file is occupied by a directory.</li>
	 * <li> The workspace is out of sync with the project description file 
	 *   in the local file system .</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * <li> The file modification validator disallowed the change.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 *
	 * @see #getDescription()
	 * @see IProjectNature#configure()
	 * @see IProjectNature#deconfigure()
	 * @see #setDescription(IProjectDescription,int,IProgressMonitor)
	 */
	public void setDescription(IProjectDescription description, IProgressMonitor monitor) throws CoreException;

	/**
	 * Changes this project resource to match the given project
	 * description. This project should exist and be open.
	 * <p>
	 * The given project description is used to change the project's
	 * natures, build spec, comment, and referenced projects.
	 * The name and location of a project cannot be changed using this method; 
	 * these settings in the project description are ignored.  To change a project's
	 * name or location, use {@link IResource#move(IProjectDescription, int, IProgressMonitor)}.
	 * The project's session and persistent properties are not affected.
	 * </p>
	 * <p>
	 * If the new description includes nature ids of natures that the project
	 * did not have before, these natures will be configured in automatically, 
	 * which involves instantiating the project nature and calling 
	 * {@link IProjectNature#configure()} on it. An internal reference to the
	 * nature object is retained, and will be returned on subsequent calls to
	 * <code>getNature</code> for the specified nature id. Similarly, any natures
	 * the project had which are no longer required will be automatically 
	 * de-configured by calling {@link IProjectNature#deconfigure}
	 * on the nature object and letting go of the internal reference to it.
	 * </p>
	 * <p>
	 * The <code>FORCE</code> update flag controls how this method deals with
	 * cases where the workspace is not completely in sync with the local file 
	 * system. If <code>FORCE</code> is not specified, the method will only attempt
	 * to overwrite the project's description file in the local file system 
	 * provided it is in sync with the workspace. This option ensures there is no 
	 * unintended data loss; it is the recommended setting.
	 * However, if <code>FORCE</code> is specified, an attempt will be made
	 * to write the project description file in the local file system, overwriting
	 * any existing one if need be.
	 * </p>
	 * <p>
	 * The <code>KEEP_HISTORY</code> update flag controls whether or not a copy of
	 * current contents of the project description file should be captured in the
	 * workspace's local history. The local history mechanism serves as a safety net
	 * to help the user recover from mistakes that might otherwise result in data
	 * loss. Specifying <code>KEEP_HISTORY</code> is recommended. Note that local
	 * history is maintained with each individual project, and gets discarded when
	 * a project is deleted from the workspace.
	 * </p>
	 * <p>
	 * The <code>AVOID_NATURE_CONFIG</code> update flag controls whether or 
	 * not added and removed natures should be configured or de-configured. If this
	 * flag is not specified, then added natures will be configured and removed natures
	 * will be de-configured. If this flag is specified, natures can still be added or
	 * removed, but they will not be configured or de-configured.
	 * </p>
	 * <p>
	 * The scheduling rule required for this operation depends on the 
	 * <code>AVOID_NATURE_CONFIG</code> flag. If the flag is specified the 
	 * {@link IResourceRuleFactory#modifyRule} is required; If the flag is not specified, 
	 * the {@link IWorkspaceRoot} scheduling rule is required. 
	 * </p>
	 * <p>
	 * Update flags other than <code>FORCE</code>, <code>KEEP_HISTORY</code>,
	 * and <code>AVOID_NATURE_CONFIG</code> are ignored.
	 * </p>
	 * <p>
	 * Prior to modifying the project description file, the file modification
	 * validator (if provided by the Team plug-in), will be given a chance to 
	 * perform any last minute preparations.  Validation is performed by calling
	 * <code>IFileModificationValidator.validateSave</code> on the project 
	 * description file. If the validation fails, then this operation will fail.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that the project's content has changed.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 *
	 * @param description the project description
	 * @param updateFlags bit-wise or of update flag constants
	 *   (<code>FORCE</code>, <code>KEEP_HISTORY</code> and
	 * <code>AVOID_NATURE_CONFIG</code>)
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @exception CoreException if this method fails. Reasons include:
	 * <ul>
	 * <li> This project does not exist in the workspace.</li>
	 * <li> This project is not open.</li>
	 * <li> The location in the local file system corresponding to the project
	 *   description file is occupied by a directory.</li>
	 * <li> The workspace is not in sync with the project
	 *   description file in the local file system and <code>FORCE</code> is not
	 *   specified.</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *   event notification. See <code>IResourceChangeEvent</code> for more details.</li>
	 * <li> The file modification validator disallowed the change.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 *
	 * @see #getDescription()
	 * @see IProjectNature#configure()
	 * @see IProjectNature#deconfigure()
	 * @see IResource#FORCE
	 * @see IResource#KEEP_HISTORY
	 * @see IResource#AVOID_NATURE_CONFIG
	 * @see IResourceRuleFactory#modifyRule(IResource)
	 * @since 2.0
	 */
	public void setDescription(IProjectDescription description, int updateFlags, IProgressMonitor monitor) throws CoreException;
}
