Compare/ReplaceWithPrevious support for multiple resources (in mappings)

The CompareWithPrevious and ReplaceWithPrevious actions now also support
scenarios where the current selection consists of a single object but
maps to multiple files (commonly via ResourceMappings).

The previous commit is the next-to-last commit which touched any of the
resources.

Bug: 496916
Change-Id: I1a208bd9949711e602309cac702a5a158b0eab4b
Signed-off-by: Stefan Dirix <sdirix@eclipsesource.com>
Signed-off-by: Philip Langer <planger@eclipsesource.com>
Also-by: Laurent Delaigue <laurent.delaigue@obeo.fr>
Also-by: Mathieu Cartaud <mathieu.cartaud@obeo.fr>

4 files changed, 143 insertions, 60 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/CommonUtils.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/CommonUtils.java
index bc738fce5e..0078fd799e 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/CommonUtils.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/CommonUtils.java
@@ -6,6 +6,7 @@
  * Copyright (C) 2014, IBM Corporation (Markus Keller <markus_keller@ch.ibm.com>)
  * Copyright (C) 2015, IBM Corporation (Dani Megert <daniel_megert@ch.ibm.com>)
  * Copyright (C) 2015, Thomas Wolf <thomas.wolf@paranor.ch>
+ * Copyright (C) 2016, Stefan Dirix <sdirix@eclipsesource.com>
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -18,6 +19,7 @@ import java.nio.file.Path;
 import java.util.Comparator;
 import java.util.Iterator;
 import java.util.LinkedList;
+import java.util.List;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -29,6 +31,7 @@ import org.eclipse.core.resources.IResource;
 import org.eclipse.jface.util.Policy;
 import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jgit.lib.Ref;
+import org.eclipse.jgit.util.StringUtils;
 import org.eclipse.ui.ISources;
 import org.eclipse.ui.PlatformUI;
 import org.eclipse.ui.commands.ICommandService;
@@ -263,4 +266,24 @@ public class CommonUtils {
 		}
 		return -1;
 	}
+
+	/**
+	 * Creates a comma separated list of all non-null resource names. The last
+	 * element is separated with an ampersand.
+	 *
+	 * @param resources
+	 *            the collection of {@link IResource}s.
+	 * @return A comma separated list the resource names. The last element is
+	 *         separated with an ampersand.
+	 */
+	public static String getResourceNames(Iterable<IResource> resources) {
+		final List<String> names = new LinkedList<>();
+		for (IResource resource : resources) {
+			if (resource.getName() != null) {
+				names.add(resource.getName());
+			}
+		}
+
+		return StringUtils.join(names, ", ", " & "); //$NON-NLS-1$ //$NON-NLS-2$
+	}
 }
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareWithPreviousActionHandler.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareWithPreviousActionHandler.java
index 56f0033f4b..78c744382a 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareWithPreviousActionHandler.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareWithPreviousActionHandler.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- *  Copyright (c) 2011, 2013 GitHub Inc. and others.
+ *  Copyright (c) 2011, 2016 GitHub Inc. 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
@@ -9,12 +9,14 @@
  *    Kevin Sawicki (GitHub Inc.) - initial API and implementation
  *    François Rey - gracefully ignore linked resources
  *    Laurent Goubet <laurent.goubet@obeo.fr>
+ *    Stefan Dirix <sdirix@eclipsesource.com>
  *******************************************************************************/
 package org.eclipse.egit.ui.internal.actions;
 
 import java.io.IOException;
 import java.text.MessageFormat;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicReference;
 
@@ -22,10 +24,12 @@ import org.eclipse.core.commands.ExecutionEvent;
 import org.eclipse.core.commands.ExecutionException;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.egit.ui.Activator;
+import org.eclipse.egit.ui.internal.CommonUtils;
 import org.eclipse.egit.ui.internal.CompareUtils;
 import org.eclipse.egit.ui.internal.UIText;
 import org.eclipse.egit.ui.internal.dialogs.CommitSelectDialog;
 import org.eclipse.jface.dialogs.MessageDialog;
+import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.window.Window;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.Repository;
@@ -48,23 +52,24 @@ public class CompareWithPreviousActionHandler extends RepositoryActionHandler {
 		if (repository == null) {
 			return null;
 		}
-
 		final IResource[] resources = getSelectedResources(event);
-		if (resources.length != 1) {
-			return null;
-		}
-		try {
-			IWorkbenchPage workBenchPage = HandlerUtil
-					.getActiveWorkbenchWindowChecked(event).getActivePage();
-			final PreviousCommit previous = getPreviousRevision(event,
-					resources[0]);
-			if (previous != null) {
-				CompareUtils.compare(resources, repository, Constants.HEAD,
-						previous.commit.getName(), true, workBenchPage);
+		if (resources != null && resources.length > 0) {
+			try {
+				IWorkbenchPage workBenchPage = HandlerUtil
+						.getActiveWorkbenchWindowChecked(event).getActivePage();
+				final RevCommit previous = getPreviousRevision(event,
+						resources);
+				if (previous != null) {
+					CompareUtils.compare(resources, repository, Constants.HEAD,
+							previous.getName(), true, workBenchPage);
+				} else {
+					showNotFoundDialog(event, resources);
+				}
+			} catch (Exception e) {
+				Activator.handleError(
+						UIText.CompareWithRefAction_errorOnSynchronize, e,
+						true);
 			}
-		} catch (Exception e) {
-			Activator.handleError(
-					UIText.CompareWithRefAction_errorOnSynchronize, e, true);
 		}
 
 		return null;
@@ -72,25 +77,26 @@ public class CompareWithPreviousActionHandler extends RepositoryActionHandler {
 
 	@Override
 	public boolean isEnabled() {
-		IResource[] selectedResources = getSelectedResources();
-		return super.isEnabled() && selectedResources.length == 1 &&
-				selectionMapsToSingleRepository();
+		IStructuredSelection selection = getSelection();
+		return super.isEnabled() && selection.size() == 1
+				&& selectionMapsToSingleRepository();
 	}
 
-	private PreviousCommit getPreviousRevision(final ExecutionEvent event,
-			final IResource resource) throws IOException {
+	private RevCommit getPreviousRevision(final ExecutionEvent event,
+			final IResource[] resources) throws IOException {
+		final List<RevCommit> previousList = findPreviousCommits(
+				Arrays.asList(resources));
 
-		final List<PreviousCommit> previousList = findPreviousCommits();
+		final AtomicReference<RevCommit> previous = new AtomicReference<>();
 
-		final AtomicReference<PreviousCommit> previous = new AtomicReference<>();
-		if (previousList.size() == 0)
-			showNotFoundDialog(event, resource);
-		else if (previousList.size() == 1)
+		if (previousList.size() == 0) {
+			return null;
+		} else if (previousList.size() == 1)
 			previous.set(previousList.get(0));
 		else {
 			final List<RevCommit> commits = new ArrayList<>();
-			for (PreviousCommit pc : previousList)
-				commits.add(pc.commit);
+			for (RevCommit pc : previousList)
+				commits.add(pc);
 			HandlerUtil.getActiveShell(event).getDisplay()
 					.syncExec(new Runnable() {
 						@Override
@@ -98,9 +104,8 @@ public class CompareWithPreviousActionHandler extends RepositoryActionHandler {
 							CommitSelectDialog dlg = new CommitSelectDialog(
 									HandlerUtil.getActiveShell(event), commits);
 							if (dlg.open() == Window.OK)
-								for (PreviousCommit pc : previousList)
-									if (pc.commit.equals(dlg
-											.getSelectedCommit())) {
+								for (RevCommit pc : previousList)
+									if (pc.equals(dlg.getSelectedCommit())) {
 										previous.set(pc);
 										break;
 									}
@@ -112,10 +117,14 @@ public class CompareWithPreviousActionHandler extends RepositoryActionHandler {
 	}
 
 	private void showNotFoundDialog(final ExecutionEvent event,
-			IResource resource) {
+			IResource[] resources) {
+
+		final String resourceNames = CommonUtils
+				.getResourceNames(Arrays.asList(resources));
+
 		final String message = MessageFormat
 				.format(UIText.CompareWithPreviousActionHandler_MessageRevisionNotFound,
-						resource.getName());
+						resourceNames);
 		PlatformUI.getWorkbench().getDisplay().asyncExec(new Runnable() {
 
 			@Override
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ReplaceWithPreviousActionHandler.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ReplaceWithPreviousActionHandler.java
index d4585b6fa2..54eb63a098 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ReplaceWithPreviousActionHandler.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ReplaceWithPreviousActionHandler.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (C) 2012, Mathias Kinzler <mathias.kinzler@sap.com>
+ * Copyright (C) 2012, 2016 Mathias Kinzler <mathias.kinzler@sap.com>
  * and other copyright owners as documented in the project's IP log.
  *
  * All rights reserved. This program and the accompanying materials
@@ -11,16 +11,18 @@ package org.eclipse.egit.ui.internal.actions;
 
 import java.io.IOException;
 import java.text.MessageFormat;
-import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 import org.eclipse.core.commands.ExecutionEvent;
 import org.eclipse.core.commands.ExecutionException;
 import org.eclipse.core.resources.IResource;
 import org.eclipse.core.runtime.OperationCanceledException;
+import org.eclipse.egit.ui.internal.CommonUtils;
 import org.eclipse.egit.ui.internal.UIText;
 import org.eclipse.egit.ui.internal.dialogs.CommitSelectDialog;
 import org.eclipse.jface.dialogs.MessageDialog;
+import org.eclipse.jface.viewers.IStructuredSelection;
 import org.eclipse.jface.window.Window;
 import org.eclipse.jgit.revwalk.RevCommit;
 
@@ -34,33 +36,31 @@ public class ReplaceWithPreviousActionHandler extends
 	protected String gatherRevision(ExecutionEvent event)
 			throws ExecutionException {
 		IResource[] resources = getSelectedResources(event);
-		if (resources.length != 1)
-			throw new ExecutionException(
-					"Unexpected number of selected Resources"); //$NON-NLS-1$
 		try {
-			List<PreviousCommit> pcs = findPreviousCommits();
-			List<RevCommit> previousCommits = new ArrayList<>();
-			for (PreviousCommit pc: pcs)
-				previousCommits.add(pc.commit);
-			int parentCount = previousCommits.size();
+			List<RevCommit> pcs = findPreviousCommits(Arrays.asList(resources));
+
+			int parentCount = pcs.size();
 			if (parentCount == 0) {
+				final String resourceNames = CommonUtils
+						.getResourceNames(Arrays.asList(resources));
+
 				MessageDialog
 						.openError(
 								getShell(event),
 								UIText.ReplaceWithPreviousActionHandler_NoParentCommitDialogTitle,
 								MessageFormat
 										.format(UIText.ReplaceWithPreviousActionHandler_NoParentCommitDialogMessage,
-												resources[0].getName()));
+												resourceNames));
 				throw new OperationCanceledException();
 			} else if (parentCount > 1) {
 				CommitSelectDialog dlg = new CommitSelectDialog(
-						getShell(event), previousCommits);
+						getShell(event), pcs);
 				if (dlg.open() == Window.OK)
 					return dlg.getSelectedCommit().getName();
 				else
 					throw new OperationCanceledException();
 			} else
-				return previousCommits.get(0).getName();
+				return pcs.get(0).getName();
 		} catch (IOException e) {
 			throw new ExecutionException(e.getMessage(), e);
 		}
@@ -68,8 +68,8 @@ public class ReplaceWithPreviousActionHandler extends
 
 	@Override
 	public boolean isEnabled() {
-		IResource[] selectedResources = getSelectedResources();
-		return super.isEnabled() && selectedResources.length == 1 &&
-				selectionMapsToSingleRepository();
+		IStructuredSelection selection = getSelection();
+		return super.isEnabled() && selection.size() == 1
+				&& selectionMapsToSingleRepository();
 	}
 }
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/RepositoryActionHandler.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/RepositoryActionHandler.java
index 8b26f23980..cf026ec08b 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/RepositoryActionHandler.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/RepositoryActionHandler.java
@@ -8,6 +8,7 @@
  * Copyright (C) 2012, 2013 François Rey <eclipse.org_@_francois_._rey_._name>
  * Copyright (C) 2013 Laurent Goubet <laurent.goubet@obeo.fr>
  * Copyright (C) 2015, IBM Corporation (Dani Megert <daniel_megert@ch.ibm.com>)
+ * Copyright (C) 2016, Stefan Dirix <sdirix@eclipsesource.com>
  *
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
@@ -19,6 +20,7 @@ package org.eclipse.egit.ui.internal.actions;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Iterator;
 import java.util.LinkedHashSet;
@@ -51,6 +53,8 @@ import org.eclipse.jgit.revwalk.FollowFilter;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevSort;
 import org.eclipse.jgit.revwalk.RevWalk;
+import org.eclipse.jgit.treewalk.filter.OrTreeFilter;
+import org.eclipse.jgit.treewalk.filter.TreeFilter;
 import org.eclipse.swt.widgets.Shell;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.IWorkbenchPart;
@@ -454,20 +458,18 @@ abstract class RepositoryActionHandler extends AbstractHandler {
 			return path;
 	}
 
-	protected List<PreviousCommit> findPreviousCommits() throws IOException {
-		List<PreviousCommit> result = new ArrayList<>();
+	protected RevCommit getHeadCommit(IResource resource) throws IOException {
 		Repository repository = getRepository();
-		IResource resource = getSelectedResources()[0];
 		if (resource == null) {
-			return result;
+			return null;
 		}
 		RepositoryMapping mapping = RepositoryMapping.getMapping(resource);
 		if (mapping == null) {
-			return result;
+			return null;
 		}
 		String path = mapping.getRepoRelativePath(resource);
 		if (path == null) {
-			return result;
+			return null;
 		}
 		try (RevWalk rw = new RevWalk(repository)) {
 			rw.sort(RevSort.COMMIT_TIME_DESC, true);
@@ -479,7 +481,59 @@ abstract class RepositoryActionHandler extends AbstractHandler {
 				rw.setTreeFilter(filter);
 			}
 
-			Ref head = repository.exactRef(Constants.HEAD);
+			Ref head = repository.findRef(Constants.HEAD);
+			if (head == null) {
+				return null;
+			}
+			RevCommit headCommit = rw.parseCommit(head.getObjectId());
+			rw.close();
+			return headCommit;
+		}
+	}
+
+	/**
+	 * Returns the previous commit of the given resources.
+	 *
+	 * @param resources
+	 *            The {@link IResource} for which the previous commit shall be
+	 *            determined.
+	 * @return The second to last commit which touched any of the given
+	 *         resources.
+	 * @throws IOException
+	 *             When the commit can not be parsed.
+	 */
+	protected List<RevCommit> findPreviousCommits(
+			Collection<IResource> resources) throws IOException {
+		List<RevCommit> result = new ArrayList<>();
+		Repository repository = getRepository();
+		RepositoryMapping mapping = RepositoryMapping.getMapping(resources
+				.iterator().next()
+				.getProject());
+		if (mapping == null) {
+			return result;
+		}
+		try (RevWalk rw = new RevWalk(repository)) {
+			rw.sort(RevSort.COMMIT_TIME_DESC, true);
+			rw.sort(RevSort.BOUNDARY, true);
+
+			List<TreeFilter> filters = new ArrayList<>();
+			DiffConfig diffConfig = repository.getConfig().get(DiffConfig.KEY);
+			for (IResource resource : resources) {
+				String path = mapping.getRepoRelativePath(resource);
+
+				if (path != null && path.length() > 0) {
+					filters.add(FollowFilter.create(path, diffConfig));
+				}
+			}
+
+			if (filters.size() >= 2) {
+				TreeFilter filter = OrTreeFilter.create(filters);
+				rw.setTreeFilter(filter);
+			} else if (filters.size() == 1) {
+				rw.setTreeFilter(filters.get(0));
+			}
+
+			Ref head = repository.findRef(Constants.HEAD);
 			if (head == null) {
 				return result;
 			}
@@ -495,10 +549,7 @@ abstract class RepositoryActionHandler extends AbstractHandler {
 			RevCommit previousCommit = rw.next();
 			while (previousCommit != null && result.size() < directParents.size()) {
 				if (directParents.contains(previousCommit)) {
-					String previousPath = getPreviousPath(repository,
-							rw.getObjectReader(), headCommit, previousCommit,
-							path);
-					result.add(new PreviousCommit(previousCommit, previousPath));
+					result.add(previousCommit);
 				}
 				previousCommit = rw.next();
 			}