bundles/org.eclipse.team.core/src/org/eclipse/team/core/RepositoryProvider.java - gerrit/platform/eclipse.platform.team - Git at Google

 /*******************************************************************************
  * Copyright (c) 2002 IBM Corporation and others.
  * All rights reserved.   This program and the accompanying materials
  * are made available under the terms of the Common Public License v0.5
  * which accompanies this distribution, and is available at
  * http://www.eclipse.org/legal/cpl-v05.html
  *
  * Contributors:
  * IBM - Initial API and implementation
  ******************************************************************************/
 package org.eclipse.team.core;

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

 import org.eclipse.core.resources.IFileModificationValidator;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IProjectDescription;
 import org.eclipse.core.resources.IProjectNature;
 import org.eclipse.core.resources.IProjectNatureDescriptor;
 import org.eclipse.core.resources.IWorkspace;
 import org.eclipse.core.resources.ResourcesPlugin;
 import org.eclipse.core.resources.team.IMoveDeleteHook;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IExtensionPoint;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.QualifiedName;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.team.internal.core.*;
 import org.eclipse.team.internal.core.Policy;
 import org.eclipse.team.internal.core.simpleAccess.SimpleAccessOperations;

 /**
  * A concrete subclass of <code>RepositoryProvider</code> is created for each
  * project that is associated with a repository provider. The lifecycle of these
  * instances is managed by the platform's 'nature' mechanism.
  * <p>
  * To create a repository provider and have it registered with the platform a client
  * must minimally:
  * <ol>
  * 	<li>extend <code>RepositoryProvider<code>
  * 	<li>define a nature extension in <code>plugin.xml</code> that is
  * 	part of the "org.eclipse.team.repository-provider" set. Having the repository nature
  * 	assigned to the team set allows cardinality restrictions to be inforced by the platform
  * 	(e.g. one repository provider can assigned to a project at a time). Here is an
  * 	example extension point definition:
  * 		<code>
  * 		<extension point="org.eclipse.core.resources.natures" id="myprovidernature" name="MyRepositoryType">
  *		 	<runtime>
  *		 		<run class="org.eclipse.myprovider.MyRepositoryProvider"/>
  *		 	</runtime>
  *		 	<one-of-nature id="org.eclipse.team.repository-provider"/>
  *		    </extension>
  *		    </p>
  *		    </code>
  * </ol></p>
  * <p>
  * Once a repository provider is registered as a nature and is in the team set, then you
  * can associate a repository provider with a project by assigning to the project the
  * nature id of the repository provider.
  * </p>
  * @see IProjectNature
  * @see RepositoryProviderType
  *
  * @since 2.0
  */
 public abstract class RepositoryProvider implements IProjectNature {

 	private final static String TEAM_SETID = "org.eclipse.team.repository-provider"; //$NON-NLS-1$

 	private final static QualifiedName PROVIDER_PROP_KEY =
 		new QualifiedName("org.eclipse.team.core", "repository");  //$NON-NLS-1$  //$NON-NLS-2$

 	private final static List AllProviderTypeIds = initializeAllProviderTypes();

 	// the project instance that this nature is assigned to
 	private IProject project;

 	/**
 	 * Instantiate a new RepositoryProvider with concrete class by given providerID
 	 * and associate it with project.
 	 * @throws TeamException
 	 * <ul>
 	 * <li>There is no provider by that ID.</li>
 	 * <li>The project is already associated with a repository provider.</li>
 	 * </ul>
 	 * @see unmap(IProject)
 	 */
 	public static void map(IProject project, String id) throws TeamException {
 		try {
 			RepositoryProvider existingProvider = null;

 			if(project.getPersistentProperty(PROVIDER_PROP_KEY) != null)
 				existingProvider = getProvider(project);	// get the real one, not the nature one

 			//if we already have a provider, and its the same ID, we're ok
 			//if the ID's differ, unmap the existing.
 			if(existingProvider != null) {
 				if(existingProvider.getID().equals(id))
 					return;	//nothing to do
 				else
 					unmap(project);
 			}

 			RepositoryProvider provider = mapNewProvider(project, id);
 			project.setPersistentProperty(PROVIDER_PROP_KEY, id);

 			try {
 				provider.configureProject();	//xxx not sure if needed since they control with wiz page and can configure all they want
 			} catch (CoreException e) {
 				project.setPersistentProperty(PROVIDER_PROP_KEY, null);
 				throw e;
 			}
 			//and mark it with the persistent ID for filtering and session persistence
 		} catch (CoreException e) {
 			throw TeamPlugin.wrapException(e);
 		}
 	}

 	/*
 	 * Instantiate the provider denoted by ID and store it in the session property.
 	 * Return the new provider instance.
 	 * @throws TeamException if the we can't instantiate the provider,
 	 * or if the set session property fails from core
 	 */
 	private static RepositoryProvider mapNewProvider(IProject project, String id) throws TeamException {
 		RepositoryProvider provider = newProvider(id); 	// instantiate via extension point

 		if(provider == null)
 			throw new TeamException(Policy.bind("RepositoryProvider.couldNotInstantiateProvider", project.getName(), id));

 		provider.setProject(project);
 		//store provider instance as session property
 		try {
 			project.setSessionProperty(PROVIDER_PROP_KEY, provider);
 		} catch (CoreException e) {
 			throw TeamPlugin.wrapException(e);
 		}
 		return provider;
 	}

 	/**
 	 * Disassoociates project with the repository provider its currently mapped to.
 	 * @throws TeamException The project isn't associated with any repository provider.
 	 */
 	public static void unmap(IProject project) throws TeamException {
 		try{
 			boolean hasProviderAssociated = project.getPersistentProperty(PROVIDER_PROP_KEY) != null;

 			//If you tried to remove a non-existance nature it would fail, so we need to as well with the persistent prop
 			if(! hasProviderAssociated)
 				throw new TeamException(Policy.bind("RepositoryProvider.No_Provider_Registered", project.getName())); //$NON-NLS-1$

 			//This will instantiate one if it didn't already exist,
 			//which is ok since we need to call deconfigure() on it for proper lifecycle
 			getProvider(project).deconfigure();

 			project.setSessionProperty(PROVIDER_PROP_KEY, null);
 			project.setPersistentProperty(PROVIDER_PROP_KEY, null);

 			//removing the nature would've caused project description delta, so trigger one
 			project.setDescription(project.getDescription(), null);
 		} catch (CoreException e) {
 			throw TeamPlugin.wrapException(e);
 		}
 	}

 	/*
 	 * Return the provider mapped to project, or null if none;
 	 */
 	private static RepositoryProvider lookupProviderProp(IProject project) throws CoreException {
 		return (RepositoryProvider) project.getSessionProperty(PROVIDER_PROP_KEY);
 	}


 	/**
 	 * Default constructor required for the resources plugin to instantiate this class from
 	 * the nature extension definition.
 	 */
 	public RepositoryProvider() {
 	}

 	/**
 	 * Configures the nature for the given project. This method is called after <code>setProject</code>
 	 * and before the nature is added to the project. If an exception is generated during configuration
 	 * of the project, the nature will not be assigned to the project.
 	 *
 	 * @throws CoreException if the configuration fails.
 	 */
 	abstract public void configureProject() throws CoreException;

 	/**
 	 * Configures the nature for the given project. This is called by the platform when a nature is assigned
 	 * to a project. It is not intended to be called by clients.
 	 *
 	 * @throws CoreException if this method fails. If the configuration fails the nature will not be added
 	 * to the project.
 	 *
 	 * @see IProjectNature#configure
 	 */
 	final public void configure() throws CoreException {
 		try {
 			configureProject();
 		} catch(CoreException e) {
 			try {
 				RepositoryProvider.unmap(getProject());
 			} catch(TeamException e2) {
 				throw new CoreException(new Status(IStatus.ERROR, TeamPlugin.ID, 0, Policy.bind("RepositoryProvider_Error_removing_nature_from_project___1") + getID(), e2)); //$NON-NLS-1$
 			}
 			throw e;
 		}
 	}

 	/**
 	 * Answer the id of this provider instance. The id should be the repository provider's
 	 * nature id.
 	 *
 	 * @return the nature id of this provider
 	 */
 	abstract public String getID();

 	/**
 	 * Returns an <code>IFileModificationValidator</code> for pre-checking operations
  	 * that modify the contents of files.
  	 * Returns <code>null</code> if the provider does not wish to participate in
  	 * file modification validation.
  	 *
 	 * @see org.eclipse.core.resources.IFileModificationValidator
 	 */

 	public IFileModificationValidator getFileModificationValidator() {
 		return null;
 	}

 	/**
 	 * Returns an <code>IMoveDeleteHook</code> for handling moves and deletes
 	 * that occur withing projects managed by the provider. This allows providers
 	 * to control how moves and deletes occur and includes the ability to prevent them.
 	 * <p>
 	 * Returning <code>null</code> signals that the default move and delete behavior is desired.
 	 *
 	 * @see org.eclipse.core.resources.IMoveDeleteHook
 	 */
 	public IMoveDeleteHook getMoveDeleteHook() {
 		return null;
 	}

 	/**
 	 * Returns a brief description of this provider. The exact details of the
 	 * representation are unspecified and subject to change, but the following
 	 * may be regarded as typical:
 	 *
 	 * "SampleProject:org.eclipse.team.cvs.provider"
 	 *
 	 * @return a string description of this provider
 	 */
 	public String toString() {
 		return Policy.bind("RepositoryProvider.toString", getProject().getName(), getID());   //$NON-NLS-1$
 	}

 	/**
 	 * Returns all known (registered) RepositoryProvider ids.
 	 *
 	 * @return an array of registered repository provider ids.
 	 */
 	final public static String[] getAllProviderTypeIds() {
 		IProjectNatureDescriptor[] desc = ResourcesPlugin.getWorkspace().getNatureDescriptors();
 		List teamSet = new ArrayList();

 		teamSet.addAll(AllProviderTypeIds);	// add in all the ones we know via extension point

 		//fall back to old method of nature ID to find any for backwards compatibility
 		for (int i = 0; i < desc.length; i++) {
 			String[] setIds = desc[i].getNatureSetIds();
 			for (int j = 0; j < setIds.length; j++) {
 				if(setIds[j].equals(TEAM_SETID)) {
 					teamSet.add(desc[i].getNatureId());
 				}
 			}
 		}
 		return (String[]) teamSet.toArray(new String[teamSet.size()]);
 	}

 	/**
 	 * Returns the provider for a given IProject or <code>null</code> if a provider is not associated with
 	 * the project or if the project is closed or does not exist. This method should be called if the caller
 	 * is looking for <b>any</b> repository provider. Otherwise call <code>getProvider(project, id)</code>
 	 * yo look for a specific repository provider type.
 	 * </p>
 	 * @param project the project to query for a provider
 	 * @return the repository provider associated with the project
 	 */
 	final public static RepositoryProvider getProvider(IProject project) {
 		try {
 			if(project.isAccessible()) {

 				//-----------------------------
 				//First check if we are using the persistent property to tag the project with provider

 				//
 				String id = project.getPersistentProperty(PROVIDER_PROP_KEY);
 				RepositoryProvider provider = lookupProviderProp(project);  //throws core, we will reuse the catching already here

 				//If we have the session but not the persistent, we have a problem
 				//because we somehow got only halfway through mapping before
 				if(id == null && provider != null) {
 					TeamPlugin.log(IStatus.ERROR, Policy.bind("RepositoryProvider.propertyMismatch", project.getName()), null);
 					project.setSessionProperty(PROVIDER_PROP_KEY, null); //clears it
 					return null;
 				}

 				if(provider != null)
 					return provider;

 				//check if it has the ID as a persistent property, if yes then instantiate provider
 				if(id != null)
 					return mapNewProvider(project, id);

 				//Couldn't find using new method, fall back to lookup using natures for backwards compatibility
 				//-----------------------------

 				IProjectDescription projectDesc = project.getDescription();
 				String[] natureIds = projectDesc.getNatureIds();
 				IWorkspace workspace = ResourcesPlugin.getWorkspace();
 				// for every nature id on this project, find it's natures sets and check if it is
 				// in the team set.
 				for (int i = 0; i < natureIds.length; i++) {
 					IProjectNatureDescriptor desc = workspace.getNatureDescriptor(natureIds[i]);
 					// The descriptor can be null if the nature doesn't exist
 					if (desc != null) {
 						String[] setIds = desc.getNatureSetIds();
 						for (int j = 0; j < setIds.length; j++) {
 							if(setIds[j].equals(TEAM_SETID)) {
 								return getProvider(project, natureIds[i]);
 							}
 						}
 					}
 				}
 			}
 		} catch(CoreException e) {
 			TeamPlugin.log(e.getStatus());
 		} catch(TeamException e) {
 			TeamPlugin.log(e.getStatus());
 		}
 		return null;
 	}

 	/**
 	 * Returns a provider of type with the given id if associated with the given project
 	 * or <code>null</code> if the project is not associated with a provider of that type
 	 * or the nature id is that of a non-team repository provider nature.
 	 *
 	 * @param project the project to query for a provider
 	 * @param id the repository provider id
 	 * @return the repository provider
 	 */
 	final public static RepositoryProvider getProvider(IProject project, String id) {
 		try {
 			if(project.isAccessible()) {
 				String existingID = project.getPersistentProperty(PROVIDER_PROP_KEY);

 				if(id.equals(existingID)) {
 					//if the IDs are the same then they were previously mapped
 					//see if we already instantiated one
 					RepositoryProvider provider = lookupProviderProp(project);  //throws core, we will reuse the catching already here
 					if(provider != null)
 						return provider;
 					//otherwise instantiate and map a new one
 					return mapNewProvider(project, id);
 				}

 				//couldn't find using new method, fall back to lookup using natures for backwards compatibility
 				//-----------------------------

 				// if the nature id given is not in the team set then return
 				// null.
 				IProjectNatureDescriptor desc = ResourcesPlugin.getWorkspace().getNatureDescriptor(id);
 				if(desc == null) //for backwards compat., may not have any nature by that ID
 					return null;

 				String[] setIds = desc.getNatureSetIds();
 				for (int i = 0; i < setIds.length; i++) {
 					if(setIds[i].equals(TEAM_SETID)) {
 						return (RepositoryProvider)project.getNature(id);
 					}
 				}
 			}
 		} catch(CoreException e) {
 			// would happen if provider nature id is not registered with the resources plugin
 			TeamPlugin.log(new Status(IStatus.WARNING, TeamPlugin.ID, 0, Policy.bind("RepositoryProviderTypeRepositoryProvider_not_registered_as_a_nature_id___3", id), e)); //$NON-NLS-1$
 		} catch(TeamException e) {
 			TeamPlugin.log(e.getStatus());
 		}
 		return null;
 	}

 	/*
 	 * Provisional.
  	 * Returns an object which implements a set of provider neutral operations for this
  	 * provider. Answers <code>null</code> if the provider does not wish to support these
  	 * operations.
  	 *
  	 * @return the repository operations or <code>null</code> if the provider does not
  	 * support provider neutral operations.
  	 */
 	public SimpleAccessOperations getSimpleAccess() {
  		return null;
  	}

 	/*
 	 * @see IProjectNature#getProject()
 	 */
 	public IProject getProject() {
 		return project;
 	}

 	/*
 	 * @see IProjectNature#setProject(IProject)
 	 */
 	public void setProject(IProject project) {
 		this.project = project;
 	}

 	private static List initializeAllProviderTypes() {
 		List allIDs = new ArrayList();

 		TeamPlugin plugin = TeamPlugin.getPlugin();
 		if (plugin != null) {
 			IExtensionPoint extension = plugin.getDescriptor().getExtensionPoint(TeamPlugin.REPOSITORY_EXTENSION);
 			if (extension != null) {
 				IExtension[] extensions =  extension.getExtensions();
 				for (int i = 0; i < extensions.length; i++) {
 					IConfigurationElement [] configElements = extensions[i].getConfigurationElements();
 					for (int j = 0; j < configElements.length; j++) {
 						String extensionId = configElements[j].getAttribute("id"); //$NON-NLS-1$
 						allIDs.add(extensionId);
 					}
 				}
 			}
 		}
 		return allIDs;
 	}

 	private static RepositoryProvider newProvider(String id) {
 		TeamPlugin plugin = TeamPlugin.getPlugin();
 		if (plugin != null) {
 			IExtensionPoint extension = plugin.getDescriptor().getExtensionPoint(TeamPlugin.REPOSITORY_EXTENSION);
 			if (extension != null) {
 				IExtension[] extensions =  extension.getExtensions();
 				for (int i = 0; i < extensions.length; i++) {
 					IConfigurationElement [] configElements = extensions[i].getConfigurationElements();
 					for (int j = 0; j < configElements.length; j++) {
 						String extensionId = configElements[j].getAttribute("id"); //$NON-NLS-1$
 						if (extensionId != null && extensionId.equals(id)) {
 							try {
 								return (RepositoryProvider) configElements[j].createExecutableExtension("class"); //$NON-NLS-1$
 							} catch (CoreException e) {
 								TeamPlugin.log(e.getStatus());
 								return null;
 							}
 						}
 					}
 				}
 			}
 		}
 		return null;
 	}

 	/*
 	 * Convert a project that are using natures to mark them as Team projects
 	 * to instead use persistent properties. Optionally remove the nature from the project.
 	 * Do nothing if the project has no Team nature.
 	 * Assume that the same ID is used for both the nature and the persistent property.
 	 */
 	public static void convertNatureToProperty(IProject project, boolean removeNature) throws TeamException {
 		RepositoryProvider provider = RepositoryProvider.getProvider(project);
 		if(provider == null)
 			return;

 		String providerId = provider.getID();

 		RepositoryProvider.map(project, providerId);
 		if(removeNature) {
 			Team.removeNatureFromProject(project, providerId, new NullProgressMonitor());
 		}
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2002 IBM Corporation and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Common Public License v0.5
	* which accompanies this distribution, and is available at
	* http://www.eclipse.org/legal/cpl-v05.html
	*
	* Contributors:
	* IBM - Initial API and implementation
	******************************************************************************/
	package org.eclipse.team.core;

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

	import org.eclipse.core.resources.IFileModificationValidator;
	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.resources.IProjectDescription;
	import org.eclipse.core.resources.IProjectNature;
	import org.eclipse.core.resources.IProjectNatureDescriptor;
	import org.eclipse.core.resources.IWorkspace;
	import org.eclipse.core.resources.ResourcesPlugin;
	import org.eclipse.core.resources.team.IMoveDeleteHook;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtension;
	import org.eclipse.core.runtime.IExtensionPoint;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.NullProgressMonitor;
	import org.eclipse.core.runtime.QualifiedName;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.team.internal.core.*;
	import org.eclipse.team.internal.core.Policy;
	import org.eclipse.team.internal.core.simpleAccess.SimpleAccessOperations;

	/**
	* A concrete subclass of <code>RepositoryProvider</code> is created for each
	* project that is associated with a repository provider. The lifecycle of these
	* instances is managed by the platform's 'nature' mechanism.
	* <p>
	* To create a repository provider and have it registered with the platform a client
	* must minimally:
	* <ol>
	* <li>extend <code>RepositoryProvider<code>
	* <li>define a nature extension in <code>plugin.xml</code> that is
	* part of the "org.eclipse.team.repository-provider" set. Having the repository nature
	* assigned to the team set allows cardinality restrictions to be inforced by the platform
	* (e.g. one repository provider can assigned to a project at a time). Here is an
	* example extension point definition:
	* <code>
	* <extension point="org.eclipse.core.resources.natures" id="myprovidernature" name="MyRepositoryType">
	* <runtime>
	* <run class="org.eclipse.myprovider.MyRepositoryProvider"/>
	* </runtime>
	* <one-of-nature id="org.eclipse.team.repository-provider"/>
	* </extension>
	* </p>
	* </code>
	* </ol></p>
	* <p>
	* Once a repository provider is registered as a nature and is in the team set, then you
	* can associate a repository provider with a project by assigning to the project the
	* nature id of the repository provider.
	* </p>
	* @see IProjectNature
	* @see RepositoryProviderType
	*
	* @since 2.0
	*/
	public abstract class RepositoryProvider implements IProjectNature {

	private final static String TEAM_SETID = "org.eclipse.team.repository-provider"; //$NON-NLS-1$

	private final static QualifiedName PROVIDER_PROP_KEY =
	new QualifiedName("org.eclipse.team.core", "repository"); //$NON-NLS-1$ //$NON-NLS-2$

	private final static List AllProviderTypeIds = initializeAllProviderTypes();

	// the project instance that this nature is assigned to
	private IProject project;

	/**
	* Instantiate a new RepositoryProvider with concrete class by given providerID
	* and associate it with project.
	* @throws TeamException
	* <ul>
	* <li>There is no provider by that ID.</li>
	* <li>The project is already associated with a repository provider.</li>
	* </ul>
	* @see unmap(IProject)
	*/
	public static void map(IProject project, String id) throws TeamException {
	try {
	RepositoryProvider existingProvider = null;

	if(project.getPersistentProperty(PROVIDER_PROP_KEY) != null)
	existingProvider = getProvider(project); // get the real one, not the nature one

	//if we already have a provider, and its the same ID, we're ok
	//if the ID's differ, unmap the existing.
	if(existingProvider != null) {
	if(existingProvider.getID().equals(id))
	return; //nothing to do
	else
	unmap(project);
	}

	RepositoryProvider provider = mapNewProvider(project, id);
	project.setPersistentProperty(PROVIDER_PROP_KEY, id);

	try {
	provider.configureProject(); //xxx not sure if needed since they control with wiz page and can configure all they want
	} catch (CoreException e) {
	project.setPersistentProperty(PROVIDER_PROP_KEY, null);
	throw e;
	}
	//and mark it with the persistent ID for filtering and session persistence
	} catch (CoreException e) {
	throw TeamPlugin.wrapException(e);
	}
	}

	/*
	* Instantiate the provider denoted by ID and store it in the session property.
	* Return the new provider instance.
	* @throws TeamException if the we can't instantiate the provider,
	* or if the set session property fails from core
	*/
	private static RepositoryProvider mapNewProvider(IProject project, String id) throws TeamException {
	RepositoryProvider provider = newProvider(id); // instantiate via extension point

	if(provider == null)
	throw new TeamException(Policy.bind("RepositoryProvider.couldNotInstantiateProvider", project.getName(), id));

	provider.setProject(project);
	//store provider instance as session property
	try {
	project.setSessionProperty(PROVIDER_PROP_KEY, provider);
	} catch (CoreException e) {
	throw TeamPlugin.wrapException(e);
	}
	return provider;
	}

	/**
	* Disassoociates project with the repository provider its currently mapped to.
	* @throws TeamException The project isn't associated with any repository provider.
	*/
	public static void unmap(IProject project) throws TeamException {
	try{
	boolean hasProviderAssociated = project.getPersistentProperty(PROVIDER_PROP_KEY) != null;

	//If you tried to remove a non-existance nature it would fail, so we need to as well with the persistent prop
	if(! hasProviderAssociated)
	throw new TeamException(Policy.bind("RepositoryProvider.No_Provider_Registered", project.getName())); //$NON-NLS-1$

	//This will instantiate one if it didn't already exist,
	//which is ok since we need to call deconfigure() on it for proper lifecycle
	getProvider(project).deconfigure();

	project.setSessionProperty(PROVIDER_PROP_KEY, null);
	project.setPersistentProperty(PROVIDER_PROP_KEY, null);

	//removing the nature would've caused project description delta, so trigger one
	project.setDescription(project.getDescription(), null);
	} catch (CoreException e) {
	throw TeamPlugin.wrapException(e);
	}
	}

	/*
	* Return the provider mapped to project, or null if none;
	*/
	private static RepositoryProvider lookupProviderProp(IProject project) throws CoreException {
	return (RepositoryProvider) project.getSessionProperty(PROVIDER_PROP_KEY);
	}


	/**
	* Default constructor required for the resources plugin to instantiate this class from
	* the nature extension definition.
	*/
	public RepositoryProvider() {
	}

	/**
	* Configures the nature for the given project. This method is called after <code>setProject</code>
	* and before the nature is added to the project. If an exception is generated during configuration
	* of the project, the nature will not be assigned to the project.
	*
	* @throws CoreException if the configuration fails.
	*/
	abstract public void configureProject() throws CoreException;

	/**
	* Configures the nature for the given project. This is called by the platform when a nature is assigned
	* to a project. It is not intended to be called by clients.
	*
	* @throws CoreException if this method fails. If the configuration fails the nature will not be added
	* to the project.
	*
	* @see IProjectNature#configure
	*/
	final public void configure() throws CoreException {
	try {
	configureProject();
	} catch(CoreException e) {
	try {
	RepositoryProvider.unmap(getProject());
	} catch(TeamException e2) {
	throw new CoreException(new Status(IStatus.ERROR, TeamPlugin.ID, 0, Policy.bind("RepositoryProvider_Error_removing_nature_from_project___1") + getID(), e2)); //$NON-NLS-1$
	}
	throw e;
	}
	}

	/**
	* Answer the id of this provider instance. The id should be the repository provider's
	* nature id.
	*
	* @return the nature id of this provider
	*/
	abstract public String getID();

	/**
	* Returns an <code>IFileModificationValidator</code> for pre-checking operations
	* that modify the contents of files.
	* Returns <code>null</code> if the provider does not wish to participate in
	* file modification validation.
	*
	* @see org.eclipse.core.resources.IFileModificationValidator
	*/

	public IFileModificationValidator getFileModificationValidator() {
	return null;
	}

	/**
	* Returns an <code>IMoveDeleteHook</code> for handling moves and deletes
	* that occur withing projects managed by the provider. This allows providers
	* to control how moves and deletes occur and includes the ability to prevent them.
	* <p>
	* Returning <code>null</code> signals that the default move and delete behavior is desired.
	*
	* @see org.eclipse.core.resources.IMoveDeleteHook
	*/
	public IMoveDeleteHook getMoveDeleteHook() {
	return null;
	}

	/**
	* Returns a brief description of this provider. The exact details of the
	* representation are unspecified and subject to change, but the following
	* may be regarded as typical:
	*
	* "SampleProject:org.eclipse.team.cvs.provider"
	*
	* @return a string description of this provider
	*/
	public String toString() {
	return Policy.bind("RepositoryProvider.toString", getProject().getName(), getID()); //$NON-NLS-1$
	}

	/**
	* Returns all known (registered) RepositoryProvider ids.
	*
	* @return an array of registered repository provider ids.
	*/
	final public static String[] getAllProviderTypeIds() {
	IProjectNatureDescriptor[] desc = ResourcesPlugin.getWorkspace().getNatureDescriptors();
	List teamSet = new ArrayList();

	teamSet.addAll(AllProviderTypeIds); // add in all the ones we know via extension point

	//fall back to old method of nature ID to find any for backwards compatibility
	for (int i = 0; i < desc.length; i++) {
	String[] setIds = desc[i].getNatureSetIds();
	for (int j = 0; j < setIds.length; j++) {
	if(setIds[j].equals(TEAM_SETID)) {
	teamSet.add(desc[i].getNatureId());
	}
	}
	}
	return (String[]) teamSet.toArray(new String[teamSet.size()]);
	}

	/**
	* Returns the provider for a given IProject or <code>null</code> if a provider is not associated with
	* the project or if the project is closed or does not exist. This method should be called if the caller
	* is looking for <b>any</b> repository provider. Otherwise call <code>getProvider(project, id)</code>
	* yo look for a specific repository provider type.
	* </p>
	* @param project the project to query for a provider
	* @return the repository provider associated with the project
	*/
	final public static RepositoryProvider getProvider(IProject project) {
	try {
	if(project.isAccessible()) {

	//-----------------------------
	//First check if we are using the persistent property to tag the project with provider

	//
	String id = project.getPersistentProperty(PROVIDER_PROP_KEY);
	RepositoryProvider provider = lookupProviderProp(project); //throws core, we will reuse the catching already here

	//If we have the session but not the persistent, we have a problem
	//because we somehow got only halfway through mapping before
	if(id == null && provider != null) {
	TeamPlugin.log(IStatus.ERROR, Policy.bind("RepositoryProvider.propertyMismatch", project.getName()), null);
	project.setSessionProperty(PROVIDER_PROP_KEY, null); //clears it
	return null;
	}

	if(provider != null)
	return provider;

	//check if it has the ID as a persistent property, if yes then instantiate provider
	if(id != null)
	return mapNewProvider(project, id);

	//Couldn't find using new method, fall back to lookup using natures for backwards compatibility
	//-----------------------------

	IProjectDescription projectDesc = project.getDescription();
	String[] natureIds = projectDesc.getNatureIds();
	IWorkspace workspace = ResourcesPlugin.getWorkspace();
	// for every nature id on this project, find it's natures sets and check if it is
	// in the team set.
	for (int i = 0; i < natureIds.length; i++) {
	IProjectNatureDescriptor desc = workspace.getNatureDescriptor(natureIds[i]);
	// The descriptor can be null if the nature doesn't exist
	if (desc != null) {
	String[] setIds = desc.getNatureSetIds();
	for (int j = 0; j < setIds.length; j++) {
	if(setIds[j].equals(TEAM_SETID)) {
	return getProvider(project, natureIds[i]);
	}
	}
	}
	}
	}
	} catch(CoreException e) {
	TeamPlugin.log(e.getStatus());
	} catch(TeamException e) {
	TeamPlugin.log(e.getStatus());
	}
	return null;
	}

	/**
	* Returns a provider of type with the given id if associated with the given project
	* or <code>null</code> if the project is not associated with a provider of that type
	* or the nature id is that of a non-team repository provider nature.
	*
	* @param project the project to query for a provider
	* @param id the repository provider id
	* @return the repository provider
	*/
	final public static RepositoryProvider getProvider(IProject project, String id) {
	try {
	if(project.isAccessible()) {
	String existingID = project.getPersistentProperty(PROVIDER_PROP_KEY);

	if(id.equals(existingID)) {
	//if the IDs are the same then they were previously mapped
	//see if we already instantiated one
	RepositoryProvider provider = lookupProviderProp(project); //throws core, we will reuse the catching already here
	if(provider != null)
	return provider;
	//otherwise instantiate and map a new one
	return mapNewProvider(project, id);
	}

	//couldn't find using new method, fall back to lookup using natures for backwards compatibility
	//-----------------------------

	// if the nature id given is not in the team set then return
	// null.
	IProjectNatureDescriptor desc = ResourcesPlugin.getWorkspace().getNatureDescriptor(id);
	if(desc == null) //for backwards compat., may not have any nature by that ID
	return null;

	String[] setIds = desc.getNatureSetIds();
	for (int i = 0; i < setIds.length; i++) {
	if(setIds[i].equals(TEAM_SETID)) {
	return (RepositoryProvider)project.getNature(id);
	}
	}
	}
	} catch(CoreException e) {
	// would happen if provider nature id is not registered with the resources plugin
	TeamPlugin.log(new Status(IStatus.WARNING, TeamPlugin.ID, 0, Policy.bind("RepositoryProviderTypeRepositoryProvider_not_registered_as_a_nature_id___3", id), e)); //$NON-NLS-1$
	} catch(TeamException e) {
	TeamPlugin.log(e.getStatus());
	}
	return null;
	}

	/*
	* Provisional.
	* Returns an object which implements a set of provider neutral operations for this
	* provider. Answers <code>null</code> if the provider does not wish to support these
	* operations.
	*
	* @return the repository operations or <code>null</code> if the provider does not
	* support provider neutral operations.
	*/
	public SimpleAccessOperations getSimpleAccess() {
	return null;
	}

	/*
	* @see IProjectNature#getProject()
	*/
	public IProject getProject() {
	return project;
	}

	/*
	* @see IProjectNature#setProject(IProject)
	*/
	public void setProject(IProject project) {
	this.project = project;
	}

	private static List initializeAllProviderTypes() {
	List allIDs = new ArrayList();

	TeamPlugin plugin = TeamPlugin.getPlugin();
	if (plugin != null) {
	IExtensionPoint extension = plugin.getDescriptor().getExtensionPoint(TeamPlugin.REPOSITORY_EXTENSION);
	if (extension != null) {
	IExtension[] extensions = extension.getExtensions();
	for (int i = 0; i < extensions.length; i++) {
	IConfigurationElement [] configElements = extensions[i].getConfigurationElements();
	for (int j = 0; j < configElements.length; j++) {
	String extensionId = configElements[j].getAttribute("id"); //$NON-NLS-1$
	allIDs.add(extensionId);
	}
	}
	}
	}
	return allIDs;
	}

	private static RepositoryProvider newProvider(String id) {
	TeamPlugin plugin = TeamPlugin.getPlugin();
	if (plugin != null) {
	IExtensionPoint extension = plugin.getDescriptor().getExtensionPoint(TeamPlugin.REPOSITORY_EXTENSION);
	if (extension != null) {
	IExtension[] extensions = extension.getExtensions();
	for (int i = 0; i < extensions.length; i++) {
	IConfigurationElement [] configElements = extensions[i].getConfigurationElements();
	for (int j = 0; j < configElements.length; j++) {
	String extensionId = configElements[j].getAttribute("id"); //$NON-NLS-1$
	if (extensionId != null && extensionId.equals(id)) {
	try {
	return (RepositoryProvider) configElements[j].createExecutableExtension("class"); //$NON-NLS-1$
	} catch (CoreException e) {
	TeamPlugin.log(e.getStatus());
	return null;
	}
	}
	}
	}
	}
	}
	return null;
	}

	/*
	* Convert a project that are using natures to mark them as Team projects
	* to instead use persistent properties. Optionally remove the nature from the project.
	* Do nothing if the project has no Team nature.
	* Assume that the same ID is used for both the nature and the persistent property.
	*/
	public static void convertNatureToProperty(IProject project, boolean removeNature) throws TeamException {
	RepositoryProvider provider = RepositoryProvider.getProvider(project);
	if(provider == null)
	return;

	String providerId = provider.getID();

	RepositoryProvider.map(project, providerId);
	if(removeNature) {
	Team.removeNatureFromProject(project, providerId, new NullProgressMonitor());
	}
	}
	}