Add a compare index with HEAD action

This new ActionCommand compares a staged selection against
the HEAD revision.

Change-Id: Ib74fd7d3e4fe0c309b16eb5e9d76511257663a24
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

5 files changed, 163 insertions, 0 deletions

diff --git a/org.eclipse.egit.ui/plugin.properties b/org.eclipse.egit.ui/plugin.properties
index b8c162e164..8d26dc315c 100644
--- a/org.eclipse.egit.ui/plugin.properties
+++ b/org.eclipse.egit.ui/plugin.properties
@@ -46,6 +46,7 @@ CommitAction_label=&Commit...
 CommitAction_tooltip=Commit change
 CompareWithIndexAction_label=Git &Index
 CompareWithHeadAction_label=&HEAD Revision
+CompareIndexWithHeadAction_label=Git Index With HEAD
 IgnoreAction_label=&Ignore
 ApplyPatchAction_label=Appl&y Patch...
 ShowResourceInHistoryAction_label=Show in Hist&ory
@@ -192,6 +193,7 @@ AddToIndexCommand.name = Add to Git Index
 BranchCommand.name = Branch
 CommitCommand.name = Commit
 CompareWithHeadCommand.name = Compare with HEAD Revision
+CompareIndexWithHeadCommand.name = Compare File in Git Index with HEAD Revision
 CompareWithHistoryCommand.name = Compare with History
 CompareWithIndexCommand.name = Compare with Git Index
 ReplaceWithIndexCommand.name = Replace with File in Git Index
diff --git a/org.eclipse.egit.ui/plugin.xml b/org.eclipse.egit.ui/plugin.xml
index e5bcc983fc..43cf475e84 100644
--- a/org.eclipse.egit.ui/plugin.xml
+++ b/org.eclipse.egit.ui/plugin.xml
@@ -129,6 +129,11 @@
                label="%CompareWithHeadAction_label"
                menubarPath="compareWithMenu/gitCompareWithGroup"/>
          <action
+               class="org.eclipse.egit.ui.internal.actions.CompareIndexWithHeadAction"
+               id="org.eclipse.egit.ui.internal.actions.CompareIndexWithHeadAction"
+               label="%CompareIndexWithHeadAction_label"
+               menubarPath="compareWithMenu/gitCompareWithGroup"/>
+         <action
                class="org.eclipse.egit.ui.internal.actions.IgnoreAction"
                definitionId="org.eclipse.egit.ui.team.Ignore"
                icon="$nl$/icons/obj16/ignore.gif"
@@ -3253,6 +3258,12 @@
       </command>
       <command
             categoryId="org.eclipse.egit.ui.commandCategory"
+            defaultHandler="org.eclipse.egit.ui.internal.actions.CompareIndexWithHeadActionHandler"
+            id="org.eclipse.egit.ui.team.CompareIndexWithHead"
+            name="%CompareIndexWithHeadCommand.name">
+      </command>
+      <command
+            categoryId="org.eclipse.egit.ui.commandCategory"
             defaultHandler="org.eclipse.egit.ui.internal.actions.CompareWithPreviousActionHandler"
             id="org.eclipse.egit.ui.team.CompareWithPrevious"
             name="%CompareWithPreviousCommand.name">
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ActionCommands.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ActionCommands.java
index 1f657ae803..fb92e85cfc 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ActionCommands.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/ActionCommands.java
@@ -29,6 +29,9 @@ public class ActionCommands {
 	/** "Compare with head" action command id */
 	public static final String COMPARE_WITH_HEAD_ACTION = "org.eclipse.egit.ui.team.CompareWithHead"; //$NON-NLS-1$
 
+	/** "Compare index with head" action command id */
+	public static final String COMPARE_INDEX_WITH_HEAD_ACTION = "org.eclipse.egit.ui.team.CompareIndexWithHead"; //$NON-NLS-1$
+
 	/** "Compare with index" action command id */
 	public static final String COMPARE_WITH_INDEX_ACTION = "org.eclipse.egit.ui.team.CompareWithIndex"; //$NON-NLS-1$
 
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareIndexWithHeadAction.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareIndexWithHeadAction.java
new file mode 100644
index 0000000000..1c1d211804
--- /dev/null
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareIndexWithHeadAction.java
@@ -0,0 +1,23 @@
+/*******************************************************************************
+ * Copyright (C) 2011, Bernard Leach <leachbj@bouncycastle.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.ui.internal.actions;
+
+/**
+ * Compares the index content of a file with the version of the file in
+ * the HEAD commit.
+ */
+public class CompareIndexWithHeadAction extends RepositoryAction {
+
+	/**
+	 *
+	 */
+	public CompareIndexWithHeadAction() {
+		super(ActionCommands.COMPARE_INDEX_WITH_HEAD_ACTION, new CompareIndexWithHeadActionHandler());
+	}
+}
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareIndexWithHeadActionHandler.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareIndexWithHeadActionHandler.java
new file mode 100644
index 0000000000..dddbee3ca3
--- /dev/null
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/actions/CompareIndexWithHeadActionHandler.java
@@ -0,0 +1,124 @@
+/*******************************************************************************
+ * Copyright (C) 2011, Bernard Leach <leachbj@bouncycastle.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.ui.internal.actions;
+
+import java.io.IOException;
+import java.util.Collections;
+
+import org.eclipse.compare.ITypedElement;
+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.core.runtime.IAdaptable;
+import org.eclipse.egit.core.project.RepositoryMapping;
+import org.eclipse.egit.ui.Activator;
+import org.eclipse.egit.ui.UIText;
+import org.eclipse.egit.ui.internal.CompareUtils;
+import org.eclipse.egit.ui.internal.GitCompareFileRevisionEditorInput;
+import org.eclipse.jface.viewers.IStructuredSelection;
+import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.IndexDiff;
+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.FileTreeIterator;
+import org.eclipse.jgit.treewalk.filter.PathFilterGroup;
+import org.eclipse.osgi.util.NLS;
+import org.eclipse.ui.IWorkbenchPage;
+import org.eclipse.ui.handlers.HandlerUtil;
+
+/**
+ * Compares the index content of a file with the version of the file in
+ * the HEAD commit.
+ */
+public class CompareIndexWithHeadActionHandler extends RepositoryActionHandler {
+	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);
+		final IFile baseFile = (IFile) resources[0];
+		final String gitPath = RepositoryMapping.getMapping(
+				baseFile.getProject()).getRepoRelativePath(baseFile);
+		final ITypedElement base = CompareUtils.getFileCachedRevisionTypedElement(gitPath, repository);
+
+		ITypedElement next;
+		try {
+			Ref head = repository.getRef(Constants.HEAD);
+			RevWalk rw = new RevWalk(repository);
+			RevCommit commit = rw.parseCommit(head.getObjectId());
+
+			next = CompareUtils.getFileRevisionTypedElement(gitPath,
+					commit, repository);
+		} catch (IOException e) {
+			Activator.handleError(e.getMessage(), e, true);
+			return null;
+		}
+
+		final GitCompareFileRevisionEditorInput in = new GitCompareFileRevisionEditorInput(
+				base, next, null);
+
+		IWorkbenchPage workBenchPage = HandlerUtil.getActiveWorkbenchWindowChecked(event).getActivePage();
+		CompareUtils.openInCompare(workBenchPage, in);
+
+		return null;
+	}
+
+	@Override
+	public boolean isEnabled() {
+		IStructuredSelection selection = getSelection();
+		if (selection.size() != 1)
+			return false;
+
+		IResource resource = (IResource) getAdapter(selection.getFirstElement(), IResource.class);
+		if (resource == null)
+			return false;
+
+		Repository repository = getRepository();
+		if (repository == null)
+			return false;
+
+		return isStaged(repository, resource);
+	}
+
+	private Object getAdapter(Object adaptable, Class c) {
+		if (c.isInstance(adaptable))
+			return adaptable;
+		if (adaptable instanceof IAdaptable) {
+			IAdaptable a = (IAdaptable) adaptable;
+			Object adapter = a.getAdapter(c);
+			if (c.isInstance(adapter))
+				return adapter;
+		}
+		return null;
+	}
+
+	private boolean isStaged(Repository repository,
+			IResource resource) {
+		String resRelPath = RepositoryMapping.getMapping(resource).getRepoRelativePath(resource);
+
+		try {
+			FileTreeIterator fileTreeIterator = new FileTreeIterator(repository);
+			IndexDiff indexDiff = new IndexDiff(repository, Constants.HEAD,
+					fileTreeIterator);
+			indexDiff.setFilter(PathFilterGroup.createFromStrings(Collections.singletonList(resRelPath)));
+			indexDiff.diff();
+
+			return indexDiff.getAdded().contains(resRelPath) || indexDiff.getChanged().contains(resRelPath)
+					|| indexDiff.getRemoved().contains(resRelPath);
+		} catch (IOException e) {
+			Activator.error(NLS.bind(UIText.GitHistoryPage_errorLookingUpPath,
+					resource.getFullPath().toString()), e);
+			return false;
+		}
+	}
+}