http://www.eclipse.org/platform: Core Resource Management (Eclipse Foundation) 
Copyright (c) 2004, 2015 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    James Blackburn (Broadcom Corp.) - ongoing development
    Lars Vogel  - Bug 473427

/*******************************************************************************
 * Copyright (c) 2004, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     James Blackburn (Broadcom Corp.) - ongoing development
 *     Lars Vogel <Lars.Vogel@vogella.com> - Bug 473427
 *******************************************************************************/
package org.eclipse.core.resources.mapping;

import java.util.ArrayList;
import org.eclipse.core.internal.resources.mapping.ModelProviderManager;
import org.eclipse.core.resources.*;
import org.eclipse.core.runtime.*;


A resource mapping supports the transformation of an application model
object into its underlying file system resources. It provides the
bridge between a logical element and the physical resource(s) into which it
is stored but does not provide more comprehensive model access or
manipulations.

 Mappings provide two means of model traversal. The accept method can be used to visit the resources that constitute the model object. Alternatively, a set or traversals can be obtained by calling getTraversals. A traversal contains a set of resources and a depth. This allows clients (such a repository providers) to do optimal traversals of the resources w.r.t. the operation that is being performed on the model object. 



This class may be subclassed by clients.



See Also:
Since:3.2
/**
 * A resource mapping supports the transformation of an application model
 * object into its underlying file system resources. It provides the
 * bridge between a logical element and the physical resource(s) into which it
 * is stored but does not provide more comprehensive model access or
 * manipulations.
 * <p>
 * Mappings provide two means of model traversal. The {@link #accept} method
 * can be used to visit the resources that constitute the model object. Alternatively,
 * a set or traversals can be obtained by calling {@link #getTraversals}. A traversal
 * contains a set of resources and a depth. This allows clients (such a repository providers)
 * to do optimal traversals of the resources w.r.t. the operation that is being performed
 * on the model object.
 * </p>
 * <p>
 * This class may be subclassed by clients.
 * </p>

 * @see IResource
 * @see ResourceTraversal
 * @since 3.2
 */
public abstract class ResourceMapping extends PlatformObject {

	
Accepts the given visitor for all existing resources in this mapping. The visitor's IResourceVisitor.visit method is called for each accessible resource in this mapping. 
Params:
  • context – the traversal context
  • visitor – the visitor
  • monitor – a progress monitor, or null if progress
   reporting is not desired
Throws:
  • CoreException – if this method fails. Reasons include:

      

    •  The visitor failed with this exception.
      • 

    •  The traversals for this mapping could not be obtained.
      • 

/**
	 * Accepts the given visitor for all existing resources in this mapping.
	 * The visitor's {@link IResourceVisitor#visit} method is called for each
	 * accessible resource in this mapping.
	 *
	 * @param context the traversal context
	 * @param visitor the visitor
	 * @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> The visitor failed with this exception.</li>
	 * <li> The traversals for this mapping could not be obtained.</li>
	 * </ul>
	 */
	public void accept(ResourceMappingContext context, IResourceVisitor visitor, IProgressMonitor monitor) throws CoreException {
		ResourceTraversal[] traversals = getTraversals(context, monitor);
		for (ResourceTraversal traversal : traversals)
			traversal.accept(visitor);
	}

	
Return whether this resource mapping contains all the resources
of the given mapping.


This method always returns false when the given resource
mapping's model provider id does not match that the of the receiver.



Params:
  • mapping – the given resource mapping
Returns:true if this mapping contains all the resources
of the given mapping, and false otherwise.
/**
	 * Return whether this resource mapping contains all the resources
	 * of the given mapping.
	 * <p>
	 * This method always returns <code>false</code> when the given resource
	 * mapping's model provider id does not match that the of the receiver.
	 * </p>
	 *
	 * @param mapping the given resource mapping
	 * @return <code>true</code> if this mapping contains all the resources
	 * of the given mapping, and <code>false</code> otherwise.
	 */
	public boolean contains(ResourceMapping mapping) {
		return false;
	}

	
Override equals to compare the model objects of the
mapping in order to determine equality.

Params:
  • obj – the object to compare
Returns:true if the receiver is equal to the
given object, and false otherwise.
/**
	 * Override equals to compare the model objects of the
	 * mapping in order to determine equality.
	 * @param obj the object to compare
	 * @return <code>true</code> if the receiver is equal to the
	 * given object, and <code>false</code> otherwise.
	 */
	@Override
	public boolean equals(Object obj) {
		if (obj == this)
			return true;
		if (obj instanceof ResourceMapping) {
			ResourceMapping other = (ResourceMapping) obj;
			return other.getModelObject().equals(getModelObject());
		}
		return false;
	}

	
Returns all markers of the specified type on the resources in this mapping.
If includeSubtypes is false, only markers
whose type exactly matches the given type are returned.  Returns an empty
array if there are no matching markers.

Params:
  • type – the type of marker to consider, or null to indicate all types
  • includeSubtypes – whether or not to consider sub-types of the given type
  • monitor – a progress monitor, or null if progress
   reporting is not desired
Throws:
Returns:an array of markers
/**
	 * Returns all markers of the specified type on the resources in this mapping.
	 * If <code>includeSubtypes</code> is <code>false</code>, only markers
	 * whose type exactly matches the given type are returned.  Returns an empty
	 * array if there are no matching markers.
	 *
	 * @param type the type of marker to consider, or <code>null</code> to indicate all types
	 * @param includeSubtypes whether or not to consider sub-types of the given type
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @return an array of markers
	 * @exception CoreException if this method fails.
	 */
	public IMarker[] findMarkers(String type, boolean includeSubtypes, IProgressMonitor monitor) throws CoreException {
		final ResourceTraversal[] traversals = getTraversals(ResourceMappingContext.LOCAL_CONTEXT, monitor);
		ArrayList<IMarker> result = new ArrayList<>();
		for (ResourceTraversal traversal : traversals)
			traversal.doFindMarkers(result, type, includeSubtypes);
		return result.toArray(new IMarker[result.size()]);
	}

	
Returns the application model element associated with this
resource mapping.

Returns:the application model element associated with this
resource mapping.
/**
	 * Returns the application model element associated with this
	 * resource mapping.
	 *
	 * @return the application model element associated with this
	 * resource mapping.
	 */
	public abstract Object getModelObject();

	
Return the model provider for the model object
of this resource mapping. The model provider is obtained
using the id returned from getModelProviderId().

Returns:the model provider
/**
	 * Return the model provider for the model object
	 * of this resource mapping. The model provider is obtained
	 * using the id returned from <code>getModelProviderId()</code>.
	 * @return the model provider
	 */
	public final ModelProvider getModelProvider() {
		try {
			return ModelProviderManager.getDefault().getModelProvider(getModelProviderId());
		} catch (CoreException e) {
			throw new IllegalStateException(e.getMessage());
		}
	}

	
Returns the id of the model provider that generated this resource
mapping.

Returns:the model provider id
/**
	 * Returns the id of the model provider that generated this resource
	 * mapping.
	 *
	 * @return the model provider id
	 */
	public abstract String getModelProviderId();

	
Returns the projects that contain the resources that constitute this
application model.

Returns:the projects
/**
	 * Returns the projects that contain the resources that constitute this
	 * application model.
	 *
	 * @return the projects
	 */
	public abstract IProject[] getProjects();

	
Returns one or more traversals that can be used to access all the
physical resources that constitute the logical resource. A traversal is
simply a set of resources and the depth to which they are to be
traversed. This method returns an array of traversals in order to provide
flexibility in describing the traversals that constitute a model element.


Subclasses should, when possible, include
all resources that are or may be members of the model element.
For instance, a model element should return the same list of
resources regardless of the existence of the files on the file system.
For example, if a logical resource called "form" maps to "/p1/form.xml"
and "/p1/form.java" then whether form.xml or form.java existed, they
should be returned by this method.


In some cases, it may not be possible for a model element to know all the
resources that may constitute the element without accessing the state of
the model element in another location (e.g. a repository). This method is
provided with a context which, when provided, gives access to
the members of corresponding remote containers and the contents of
corresponding remote files. This gives the model element the opportunity
to deduce what additional resources should be included in the traversal.



Params:
  • context – gives access to the state of
           remote resources that correspond to local resources for the
           purpose of determining traversals that adequately cover the
           model element resources given the state of the model element
           in another location. This parameter may be null, in
           which case the implementor can assume that only the local
           resources are of interest to the client.
  • monitor – a progress monitor, or null if progress
   reporting is not desired
Throws:
Returns:a set of traversals that cover the resources that constitute the
        model element
/**
	 * Returns one or more traversals that can be used to access all the
	 * physical resources that constitute the logical resource. A traversal is
	 * simply a set of resources and the depth to which they are to be
	 * traversed. This method returns an array of traversals in order to provide
	 * flexibility in describing the traversals that constitute a model element.
	 * <p>
	 * Subclasses should, when possible, include
	 * all resources that are or may be members of the model element.
	 * For instance, a model element should return the same list of
	 * resources regardless of the existence of the files on the file system.
	 * For example, if a logical resource called "form" maps to "/p1/form.xml"
	 * and "/p1/form.java" then whether form.xml or form.java existed, they
	 * should be returned by this method.
	 *</p><p>
	 * In some cases, it may not be possible for a model element to know all the
	 * resources that may constitute the element without accessing the state of
	 * the model element in another location (e.g. a repository). This method is
	 * provided with a context which, when provided, gives access to
	 * the members of corresponding remote containers and the contents of
	 * corresponding remote files. This gives the model element the opportunity
	 * to deduce what additional resources should be included in the traversal.
	 * </p>
	 *
	 * @param context gives access to the state of
	 *            remote resources that correspond to local resources for the
	 *            purpose of determining traversals that adequately cover the
	 *            model element resources given the state of the model element
	 *            in another location. This parameter may be <code>null</code>, in
	 *            which case the implementor can assume that only the local
	 *            resources are of interest to the client.
	 * @param monitor a progress monitor, or <code>null</code> if progress
	 *    reporting is not desired
	 * @return a set of traversals that cover the resources that constitute the
	 *         model element
	 * @exception CoreException if the traversals could not be obtained.
	 */
	public abstract ResourceTraversal[] getTraversals(ResourceMappingContext context, IProgressMonitor monitor) throws CoreException;

	
Override hashCode to use the model object.

/**
	 * Override hashCode to use the model object.
	 */
	@Override
	public int hashCode() {
		return getModelObject().hashCode();
	}
}