http://www.eclipse.org/platform: Team Support Core (Eclipse Foundation) 
Copyright (c) 2000, 2017 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation

/*******************************************************************************
 * Copyright (c) 2000, 2017 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.team.core.mapping;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.mapping.ModelProvider;
import org.eclipse.core.resources.mapping.ResourceMapping;
import org.eclipse.core.resources.mapping.ResourceTraversal;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.ISchedulingRule;
import org.eclipse.core.runtime.jobs.MultiRule;
import org.eclipse.team.core.diff.IDiff;
import org.eclipse.team.core.mapping.provider.MergeStatus;


Abstract implementation of IResourceMappingMerger. This merger delegates the merge of all resources covered by the mappings of the model provider returned from getModelProvider() back to the merge context. Subclasses should override the merge(IMergeContext, IProgressMonitor) method in order to change this behavior. 

Clients may subclass this class.

See Also:
Since:3.2
/**
 * Abstract implementation of {@link IResourceMappingMerger}. This merger
 * delegates the merge of all resources covered by the mappings of the
 * model provider returned from {@link #getModelProvider()} back to the
 * merge context. Subclasses should override the {@link #merge(IMergeContext, IProgressMonitor)}
 * method in order to change this behavior.
 *
 * <p>
 * Clients may subclass this class.
 *
 * @see IResourceMappingMerger
 *
 * @since 3.2
 */
public abstract class ResourceMappingMerger implements IResourceMappingMerger {

	@Override
	public IStatus validateMerge(IMergeContext mergeContext, IProgressMonitor monitor) {
		return Status.OK_STATUS;
	}

	
Return the model provider associated with this merger.

Returns:Return the model provider associated with this merger.
/**
	 * Return the model provider associated with this merger.
	 * @return Return the model provider associated with this merger.
	 */
	protected abstract ModelProvider getModelProvider();

	
Return the scheduling rule required to merge all the
changes in the context for the model provider of this merger.
By default, return a rule that covers all the projects for the mappings
that belong to the model provider of this merger.

Params:
  • context – the context that contains the changes to be merged
See Also:
Returns:the scheduling rule required by this merger to merge all
the changes in the given context belonging to the merger's
model provider.
/**
	 * Return the scheduling rule required to merge all the
	 * changes in the context for the model provider of this merger.
	 * By default, return a rule that covers all the projects for the mappings
	 * that belong to the model provider of this merger.
	 * @param context the context that contains the changes to be merged
	 * @return the scheduling rule required by this merger to merge all
	 * the changes in the given context belonging to the merger's
	 * model provider.
	 * @see org.eclipse.team.core.mapping.IResourceMappingMerger#getMergeRule(org.eclipse.team.core.mapping.IMergeContext)
	 */
	@Override
	public ISchedulingRule getMergeRule(IMergeContext context) {
		ResourceMapping[] mappings = context.getScope().getMappings(getModelProvider().getId());
		ISchedulingRule rule = null;
		for (ResourceMapping mapping : mappings) {
			IProject[] mappingProjects = mapping.getProjects();
			for (IProject project : mappingProjects) {
				if (rule == null) {
					rule = project;
				} else {
					rule = MultiRule.combine(rule, project);
				}
			}
		}
		return rule;
	}

	
A default implementation of merge that attempts to merge all the mappings
in the context.

Params:
  • mergeContext – the context
  • monitor – a progress monitor
Throws:
See Also:
Returns:a status indicating whether the merge was successful
/**
	 * A default implementation of merge that attempts to merge all the mappings
	 * in the context.
	 * @param mergeContext the context
	 * @param monitor a progress monitor
	 * @return a status indicating whether the merge was successful
	 * @throws CoreException if an error occurred
	 * @see org.eclipse.team.core.mapping.IResourceMappingMerger#merge(org.eclipse.team.core.mapping.IMergeContext, org.eclipse.core.runtime.IProgressMonitor)
	 */
	@Override
	public IStatus merge(IMergeContext mergeContext, IProgressMonitor monitor) throws CoreException {
		IDiff[] deltas = getSetToMerge(mergeContext);
		IStatus status = mergeContext.merge(deltas, false /* don't force */, monitor);
		return covertFilesToMappings(status, mergeContext);
	}

	private IDiff[] getSetToMerge(IMergeContext mergeContext) {
		ResourceMapping[] mappings = mergeContext.getScope().getMappings(getModelProvider().getDescriptor().getId());
		Set<IDiff> result = new HashSet<>();
		for (ResourceMapping mapping : mappings) {
			ResourceTraversal[] traversals = mergeContext.getScope().getTraversals(mapping);
			IDiff[] deltas = mergeContext.getDiffTree().getDiffs(traversals);
			Collections.addAll(result, deltas);
		}
		return result.toArray(new IDiff[result.size()]);
	}

	private IStatus covertFilesToMappings(IStatus status, IMergeContext mergeContext) {
		if (status.getCode() == IMergeStatus.CONFLICTS) {
			// In general, we can't say which mapping failed so return them all
			return new MergeStatus(status.getPlugin(), status.getMessage(), mergeContext.getScope().getMappings(getModelProvider().getDescriptor().getId()));
		}
		return status;
	}
}