org.eclipse.egit.bc.BeyondCompareWithHeadActionHandler.java Source code

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Here is the source code for org.eclipse.egit.bc.BeyondCompareWithHeadActionHandler.java

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/*******************************************************************************
 * Copyright (C) 2009, Stefan Lay <stefan.lay@sap.com>
 * Copyright (C) 2012, Robin Stocker <robin@nibor.org>
 *
 * 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
 *******************************************************************************/
package org.eclipse.egit.bc;

import java.io.IOException;

import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IResource;
import org.eclipse.egit.core.project.RepositoryMapping;
import org.eclipse.egit.ui.internal.dialogs.CompareTreeView;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jgit.errors.IncorrectObjectTypeException;
import org.eclipse.jgit.errors.MissingObjectException;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.Ref;
import org.eclipse.jgit.lib.Repository;
import org.eclipse.jgit.revwalk.RevCommit;
import org.eclipse.jgit.revwalk.RevWalk;
import org.eclipse.jgit.treewalk.filter.AndTreeFilter;
import org.eclipse.jgit.treewalk.filter.PathFilter;
import org.eclipse.jgit.treewalk.filter.TreeFilter;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.handlers.HandlerUtil;

/**
 * Compares the working tree content of a file with the version of the file in
 * the HEAD commit.
 */
public class BeyondCompareWithHeadActionHandler extends BeyondCompareRepositoryActionHandler {

    public Object execute(ExecutionEvent event) throws ExecutionException {
        final Repository repository = getRepository(true, event);
        // assert all resources map to the same repository
        if (repository == null)
            return null;
        final IResource[] resources = getSelectedResources(event);

        if (resources.length == 1 && resources[0] instanceof IFile) {
            final IFile baseFile = (IFile) resources[0];

            try {
                RepositoryMapping mapping = RepositoryMapping.getMapping(baseFile.getProject());
                String repoRelativeBasePath = mapping.getRepoRelativePath(baseFile);
                Repository localRepo = mapping.getRepository();
                RevCommit commit = getHeadRevision(repository, repoRelativeBasePath);

                String rightFilePath = BeyondCompareUtil.getCompareFilePath(repoRelativeBasePath, commit,
                        localRepo);
                String leftFilePath = baseFile.getLocation().toFile().getAbsolutePath();
                BeyondCompareUtil.execBeyondCompare(leftFilePath, rightFilePath);
            } catch (Exception e) {
                Activator.handleError(UIText.CompareWithHeadActionHandler_onError, e, true);
            }
            return null;

        } else {
            CompareTreeView view;
            try {
                view = (CompareTreeView) PlatformUI.getWorkbench().getActiveWorkbenchWindow().getActivePage()
                        .showView(CompareTreeView.ID);
                try {
                    Ref head = repository.getRef(Constants.HEAD);
                    if (head == null || head.getObjectId() == null) {
                        // Initial commit case
                        Shell shell = HandlerUtil.getActiveShell(event);
                        MessageDialog.openInformation(shell, UIText.CompareWithHeadActionHandler_NoHeadTitle,
                                UIText.CompareWithHeadActionHandler_NoHeadMessage);
                    } else
                        view.setInput(resources, Repository.shortenRefName(head.getTarget().getName()));
                } catch (IOException e) {
                    Activator.handleError(e.getMessage(), e, true);
                    return null;
                }
            } catch (PartInitException e) {
                Activator.handleError(e.getMessage(), e, true);
                return null;
            }
            return null;
        }
    }

    @Override
    public boolean isEnabled() {
        return getRepository() != null;
    }

    private static RevCommit getHeadRevision(Repository repository, String repoRelativePath)
            throws MissingObjectException, IncorrectObjectTypeException, IOException {
        Ref head = repository.getRef(Constants.HEAD);
        if (head == null || head.getObjectId() == null)
            // Initial import, not yet a HEAD commit
            return null;

        RevCommit latestFileCommit;
        RevWalk rw = new RevWalk(repository);
        try {
            RevCommit headCommit = rw.parseCommit(head.getObjectId());
            rw.markStart(headCommit);
            rw.setTreeFilter(AndTreeFilter.create(PathFilter.create(repoRelativePath), TreeFilter.ANY_DIFF));
            latestFileCommit = rw.next();
            // Fall back to HEAD
            if (latestFileCommit == null)
                latestFileCommit = headCommit;
        } finally {
            rw.release();
        }

        return latestFileCommit;

    }

}