/*******************************************************************************
 * 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.net.URI;
import org.eclipse.core.runtime.*;

/**
 * Folders may be leaf or non-leaf resources and may contain files and/or other folders.
 * A folder resource is stored as a directory in the local file system.
 * <p>
 * Folders, like other resource types, may exist in the workspace but
 * not be local; non-local folder resources serve as place-holders for
 * folders whose properties have not yet been fetched from a repository.
 * </p>
 * <p>
 * Folders 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 IFolder extends IContainer, IAdaptable {

	/**
	 * Creates a new folder resource as a member of this handle's parent resource.
	 * <p>
	 * This is a convenience method, fully equivalent to:
	 * <pre>
	 *   create((force ? FORCE : IResource.NONE), local, monitor);
	 * </pre>
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that the folder has been added to its parent.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 * 
	 * @param force a flag controlling how to deal with resources that
	 *    are not in sync with the local file system
	 * @param local a flag controlling whether or not the folder will be local
	 *    after the creation
	 * @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 already exists in the workspace.</li>
	 * <li> The workspace contains a resource of a different type 
	 *      at the same path as this resource.</li>
	 * <li> The parent of this resource does not exist.</li>
	 * <li> The parent of this resource is a project that is not open.</li>
	 * <li> The parent contains a resource of a different type 
	 *      at the same path as this resource.</li>
	 * <li> The name of this resource is not valid (according to 
	 *    <code>IWorkspace.validateName</code>).</li>
	 * <li> The corresponding location in the local file system is occupied
	 *    by a file (as opposed to a directory).</li>
	 * <li> The corresponding location in the local file system is occupied
	 *    by a folder and <code>force </code> is <code>false</code>.</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 IFolder#create(int,boolean,IProgressMonitor)
	 */
	public void create(boolean force, boolean local, IProgressMonitor monitor) throws CoreException;

	/**
	 * Creates a new folder resource as a member of this handle's parent resource.
	 * <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 create a directory in the local file system if there isn't one already. 
	 * This option ensures there is no unintended data loss; it is the recommended
	 * setting. However, if <code>FORCE</code> is specified, this method will 
	 * be deemed a success even if there already is a corresponding directory.
	 * </p>
	 * <p>
	 * The {@link IResource#DERIVED} update flag indicates that this resource
	 * should immediately be set as a derived resource.  Specifying this flag
	 * is equivalent to atomically calling {@link IResource#setDerived(boolean)}
	 * with a value of <code>true</code> immediately after creating the resource.
	 * </p>
	 * <p>
	 * The {@link IResource#TEAM_PRIVATE} update flag indicates that this resource
	 * should immediately be set as a team private resource.  Specifying this flag
	 * is equivalent to atomically calling {@link IResource#setTeamPrivateMember(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>
	 * <p>
	 * This method synchronizes this resource with the local file system.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that the folder has been added to its parent.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 * 
	 * @param updateFlags bit-wise or of update flag constants
	 *   ({@link IResource#FORCE}, {@link IResource#DERIVED}, and {@link IResource#TEAM_PRIVATE})
	 * @param local a flag controlling whether or not the folder will be local
	 *    after the creation
	 * @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 already exists in the workspace.</li>
	 * <li> The workspace contains a resource of a different type 
	 *      at the same path as this resource.</li>
	 * <li> The parent of this resource does not exist.</li>
	 * <li> The parent of this resource is a project that is not open.</li>
	 * <li> The parent contains a resource of a different type 
	 *      at the same path as this resource.</li>
	 * <li> The name of this resource is not valid (according to 
	 *    <code>IWorkspace.validateName</code>).</li>
	 * <li> The corresponding location in the local file system is occupied
	 *    by a file (as opposed to a directory).</li>
	 * <li> The corresponding location in the local file system is occupied
	 *    by a folder 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>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 * @see IResourceRuleFactory#createRule(IResource)
	 * @since 2.0
	 */
	public void create(int updateFlags, boolean local, IProgressMonitor monitor) throws CoreException;

	/**
	 * Creates a new folder resource as a member of this handle's parent resource.
	 * The folder's contents will be located in the directory specified by the given
	 * file system path.  The given path must be either an absolute file system
	 * path, or a relative path whose first segment is the name of a workspace path
	 * variable.
	 * <p>
	 * The <code>ALLOW_MISSING_LOCAL</code> update flag controls how this 
	 * method deals with cases where the local file system directory to be linked does
	 * not exist, or is relative to a workspace path variable that is not defined.
	 * If <code>ALLOW_MISSING_LOCAL</code> is specified, the operation will succeed
	 * even if the local directory is missing, or the path is relative to an
	 * undefined variable. If <code>ALLOW_MISSING_LOCAL</code> is not specified, the
	 * operation will fail in the case where the local file system directory does
	 * not exist or the path is relative to an undefined variable.
	 * </p>
	 * <p>
	 * The {@link IResource#REPLACE} update flag controls how this 
	 * method deals with cases where a resource of the same name as the 
	 * prospective link already exists. If {@link IResource#REPLACE}
	 * is specified, then any existing resource with the same name is removed
	 * from the workspace to make way for creation of the link.  This does <b>not</b>
	 * cause the underlying file system contents of that resource to be deleted.
	 * If {@link IResource#REPLACE} is not specified, this method will
	 * fail if an existing resource exists of the same name.
	 * </p>
	 * <p>
	 * The {@link IResource#BACKGROUND_REFRESH} update flag controls how
	 * this method synchronizes the new resource with the filesystem. If this flag is 
	 * specified, resources on disk will be synchronized in the background after the 
	 * method returns. Child resources of the link may not be available until 
	 * this background refresh completes. If this flag is not specified, resources are 
	 * synchronized in the foreground before this method returns.
	 * </p>
	 * <p>
	 * Update flags other than {@link IResource#ALLOW_MISSING_LOCAL} or
	 * {@link IResource#REPLACE} or {@link IResource#BACKGROUND_REFRESH} are ignored.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that the folder has been added to its parent.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 * 
	 * @param localLocation a file system path where the folder should be linked
	 * @param updateFlags bit-wise or of update flag constants
	 *   (only ALLOW_MISSING_LOCAL is relevant here) 
	 * @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 already exists in the workspace.</li>
	 * <li> The workspace contains a resource of a different type 
	 *      at the same path as this resource.</li>
	 * <li> The parent of this resource does not exist.</li>
	 * <li> The parent of this resource is not an open project</li>
	 * <li> The name of this resource is not valid (according to 
	 *    <code>IWorkspace.validateName</code>).</li>
	 * <li> The corresponding location in the local file system does not exist, or
	 * is relative to an undefined variable, and <code>ALLOW_MISSING_LOCAL</code> is
	 * not specified.</li>
	 * <li> The corresponding location in the local file system is occupied
	 *    by a file (as opposed to a directory).</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification.  See <code>IResourceChangeEvent</code> for more details.</li>
	 * <li>The team provider for the project which contains this folder does not permit
	 *       linked resources.</li>
	 * <li>This folder's project contains a nature which does not permit linked resources.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 * @see IResource#isLinked()
	 * @see IResource#ALLOW_MISSING_LOCAL
	 * @since 2.1
	 */
	public void createLink(IPath localLocation, int updateFlags, IProgressMonitor monitor) throws CoreException;

	/**
	 * Creates a new folder resource as a member of this handle's parent resource.
	 * The folder's contents will be located in the directory specified by the given
	 * file system URI.  The given URI must be either absolute, or a relative URI 
	 * whose first path segment is the name of a workspace path variable.
	 * <p>
	 * The <code>ALLOW_MISSING_LOCAL</code> update flag controls how this 
	 * method deals with cases where the local file system directory to be linked does
	 * not exist, or is relative to a workspace path variable that is not defined.
	 * If <code>ALLOW_MISSING_LOCAL</code> is specified, the operation will succeed
	 * even if the local directory is missing, or the path is relative to an
	 * undefined variable. If <code>ALLOW_MISSING_LOCAL</code> is not specified, the
	 * operation will fail in the case where the local file system directory does
	 * not exist or the path is relative to an undefined variable.
	 * </p>
	 * <p>
	 * The {@link IResource#REPLACE} update flag controls how this 
	 * method deals with cases where a resource of the same name as the 
	 * prospective link already exists. If {@link IResource#REPLACE}
	 * is specified, then any existing resource with the same name is removed
	 * from the workspace to make way for creation of the link.  This does <b>not</b>
	 * cause the underlying file system contents of that resource to be deleted.
	 * If {@link IResource#REPLACE} is not specified, this method will
	 * fail if an existing resource exists of the same name.
	 * </p>
	 * <p>
	 * The {@link IResource#BACKGROUND_REFRESH} update flag controls how
	 * this method synchronizes the new resource with the filesystem. If this flag is 
	 * specified, resources on disk will be synchronized in the background after the 
	 * method returns. Child resources of the link may not be available until 
	 * this background refresh completes. If this flag is not specified, resources are 
	 * synchronized in the foreground before this method returns.
	 * </p>
	 * <p>
	 * Update flags other than {@link IResource#ALLOW_MISSING_LOCAL} or
	 * {@link IResource#REPLACE} or {@link IResource#BACKGROUND_REFRESH} are ignored.
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that the folder has been added to its parent.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 * 
	 * @param location a file system path where the folder should be linked
	 * @param updateFlags bit-wise or of update flag constants
	 *   (only ALLOW_MISSING_LOCAL is relevant here) 
	 * @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 already exists in the workspace.</li>
	 * <li> The workspace contains a resource of a different type 
	 *      at the same path as this resource.</li>
	 * <li> The parent of this resource does not exist.</li>
	 * <li> The parent of this resource is not an open project</li>
	 * <li> The name of this resource is not valid (according to 
	 *    <code>IWorkspace.validateName</code>).</li>
	 * <li> The corresponding location in the local file system does not exist, or
	 * is relative to an undefined variable, and <code>ALLOW_MISSING_LOCAL</code> is
	 * not specified.</li>
	 * <li> The corresponding location in the local file system is occupied
	 *    by a file (as opposed to a directory).</li>
	 * <li> Resource changes are disallowed during certain types of resource change 
	 *       event notification.  See <code>IResourceChangeEvent</code> for more details.</li>
	 * <li>The team provider for the project which contains this folder does not permit
	 *       linked resources.</li>
	 * <li>This folder's project contains a nature which does not permit linked resources.</li>
	 * </ul>
	 * @exception OperationCanceledException if the operation is canceled. 
	 * Cancelation can occur even if no progress monitor is provided.
	 * @see IResource#isLinked()
	 * @see IResource#ALLOW_MISSING_LOCAL
	 * @since 3.2
	 */
	public void createLink(URI location, int updateFlags, IProgressMonitor monitor) throws CoreException;

	/**
	 * Deletes this resource from the workspace.
	 * <p>
	 * This is a convenience method, fully equivalent to:
	 * <pre>
	 *   delete((keepHistory ? KEEP_HISTORY : IResource.NONE) | (force ? FORCE : IResource.NONE), monitor);
	 * </pre>
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that this folder has been removed from its parent.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 * 
	 * @param force a flag controlling whether resources that are not
	 *    in sync with the local file system will be tolerated
	 * @param keepHistory a flag controlling whether files under this folder
	 *    should be stored in the workspace's local history
	 * @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 could not be deleted for some reason.</li>
	 * <li> This resource is out of sync with the local file system
	 *      and <code>force</code> is <code>false</code>.</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 IResourceRuleFactory#deleteRule(IResource)
	 * @see IResource#delete(int,IProgressMonitor)
	 */
	public void delete(boolean force, boolean keepHistory, IProgressMonitor monitor) throws CoreException;

	/**
	 * Returns a handle to the file with the given name in this folder.
	 * <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 folder.
	 * <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);

	/**
	 * Moves this resource so that it is located at the given path.  
	 * <p>
	 * This is a convenience method, fully equivalent to:
	 * <pre>
	 *   move(destination, (keepHistory ? KEEP_HISTORY : IResource.NONE) | (force ? FORCE : IResource.NONE), monitor);
	 * </pre>
	 * </p>
	 * <p>
	 * This method changes resources; these changes will be reported
	 * in a subsequent resource change event, including an indication 
	 * that this folder has been removed from its parent and a new folder
	 * has been added to the parent of the destination.
	 * </p>
	 * <p>
	 * This method is long-running; progress and cancellation are provided
	 * by the given progress monitor. 
	 * </p>
	 * 
	 * @param destination the destination path 
	 * @param force a flag controlling whether resources that are not
	 *    in sync with the local file system will be tolerated
	 * @param keepHistory a flag controlling whether files under this folder
	 *    should be stored in the workspace's local history
	 * @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 does not exist.</li>
	 * <li> This resource or one of its descendents is not local.</li>
	 * <li> The resource corresponding to the parent destination path does not exist.</li>
	 * <li> The resource corresponding to the parent destination path is a closed 
	 *      project.</li>
	 * <li> A resource at destination path does exist.</li>
	 * <li> A resource of a different type exists at the destination path.</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 IResourceRuleFactory#moveRule(IResource, IResource)
	 * @see IResource#move(IPath,int,IProgressMonitor)
	 */
	public void move(IPath destination, boolean force, boolean keepHistory, IProgressMonitor monitor) throws CoreException;
}
