Add editor page for viewing diffs introduced by a commit

This page will be added to the commit viewer to see the
line by line differences of a commit.

Change-Id: Ic79104b1fa5f4aa07cb821378c785dcd474def6b
Signed-off-by: Kevin Sawicki <kevin@github.com>
Signed-off-by: Chris Aniszczyk <caniszczyk@gmail.com>

3 files changed, 215 insertions, 0 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
index 211afe4a91..37ebc687af 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
@@ -2497,6 +2497,15 @@ public class UIText extends NLS {
 	public static String DialogsPreferencePage_ShowInitialConfigCheckbox;
 
 	/** */
+	public static String DiffEditorPage_TaskGeneratingDiff;
+
+	/** */
+	public static String DiffEditorPage_TaskUpdatingViewer;
+
+	/** */
+	public static String DiffEditorPage_Title;
+
+	/** */
 	public static String DiscardChangesAction_confirmActionTitle;
 
 	/** */
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffEditorPage.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffEditorPage.java
new file mode 100644
index 0000000000..88b8b9ce87
--- /dev/null
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffEditorPage.java
@@ -0,0 +1,203 @@
+/*******************************************************************************
+ *  Copyright (c) 2011 GitHub Inc.
+ *  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
+ *
+ *  Contributors:
+ *    Kevin Sawicki (GitHub Inc.) - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.egit.ui.internal.commit;
+
+import java.io.IOException;
+
+import org.eclipse.core.runtime.IProgressMonitor;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.eclipse.core.runtime.jobs.Job;
+import org.eclipse.egit.ui.UIText;
+import org.eclipse.egit.ui.internal.history.FileDiff;
+import org.eclipse.jface.action.Action;
+import org.eclipse.jface.action.MenuManager;
+import org.eclipse.jface.action.Separator;
+import org.eclipse.jface.layout.GridDataFactory;
+import org.eclipse.jface.layout.GridLayoutFactory;
+import org.eclipse.jface.text.Document;
+import org.eclipse.jface.text.IDocument;
+import org.eclipse.jface.text.ITextOperationTarget;
+import org.eclipse.jface.text.ITextViewer;
+import org.eclipse.jface.text.source.CompositeRuler;
+import org.eclipse.jface.viewers.ISelectionChangedListener;
+import org.eclipse.jface.viewers.SelectionChangedEvent;
+import org.eclipse.jgit.lib.Repository;
+import org.eclipse.swt.SWT;
+import org.eclipse.swt.widgets.Composite;
+import org.eclipse.swt.widgets.Menu;
+import org.eclipse.ui.IEditorSite;
+import org.eclipse.ui.IWorkbenchCommandConstants;
+import org.eclipse.ui.forms.IManagedForm;
+import org.eclipse.ui.forms.editor.FormEditor;
+import org.eclipse.ui.forms.editor.FormPage;
+import org.eclipse.ui.progress.UIJob;
+import org.eclipse.ui.texteditor.AbstractTextEditor;
+import org.eclipse.ui.texteditor.IUpdate;
+
+/**
+ * Diff editor page class for displaying a {@link DiffViewer}.
+ */
+public class DiffEditorPage extends FormPage {
+
+	private static class TextViewerAction extends Action implements IUpdate {
+
+		private int code = -1;
+
+		private ITextOperationTarget target;
+
+		public TextViewerAction(ITextViewer viewer, int operationCode) {
+			code = operationCode;
+			target = viewer.getTextOperationTarget();
+			update();
+		}
+
+		public void update() {
+			if (code == ITextOperationTarget.REDO)
+				return;
+
+			boolean wasEnabled = isEnabled();
+			boolean isEnabled = target.canDoOperation(code);
+			setEnabled(isEnabled);
+
+			if (wasEnabled != isEnabled)
+				firePropertyChange(ENABLED, wasEnabled ? Boolean.TRUE
+						: Boolean.FALSE, isEnabled ? Boolean.TRUE
+						: Boolean.FALSE);
+		}
+
+		public void run() {
+			if (code != -1)
+				target.doOperation(code);
+		}
+	}
+
+	private DiffViewer viewer;
+
+	private DiffStyleRangeFormatter formatter;
+
+	/**
+	 * @param editor
+	 * @param id
+	 * @param title
+	 */
+	public DiffEditorPage(FormEditor editor, String id, String title) {
+		super(editor, id, title);
+	}
+
+	/**
+	 * @param editor
+	 */
+	public DiffEditorPage(FormEditor editor) {
+		this(editor, "diffPage", UIText.DiffEditorPage_Title); //$NON-NLS-1$
+	}
+
+	private void formatDiff() {
+		final IDocument document = new Document();
+		formatter = new DiffStyleRangeFormatter(document);
+		viewer.setFormatter(formatter);
+
+		Job job = new Job(UIText.DiffEditorPage_TaskGeneratingDiff) {
+
+			protected IStatus run(IProgressMonitor monitor) {
+				RepositoryCommit commit = (RepositoryCommit) getEditor()
+						.getAdapter(RepositoryCommit.class);
+				FileDiff diffs[] = commit.getDiffs();
+				monitor.beginTask("", diffs.length); //$NON-NLS-1$
+				Repository repository = commit.getRepository();
+				for (FileDiff diff : diffs) {
+					if (monitor.isCanceled())
+						break;
+					monitor.setTaskName(diff.getPath());
+					if (diff.getBlobs().length == 2)
+						try {
+							formatter.write(repository, diff);
+						} catch (IOException ignore) {
+							// Ignored
+						}
+					monitor.worked(1);
+				}
+				monitor.done();
+				new UIJob(UIText.DiffEditorPage_TaskUpdatingViewer) {
+
+					public IStatus runInUIThread(IProgressMonitor uiMonitor) {
+						if (!viewer.getControl().isDisposed()) {
+							viewer.setDocument(document);
+							viewer.refreshStyleRanges();
+						}
+						return Status.OK_STATUS;
+					}
+				}.schedule();
+				return Status.OK_STATUS;
+			}
+		};
+		job.schedule();
+	}
+
+	/**
+	 * Add editor actions to menu manager
+	 *
+	 * @param manager
+	 */
+	protected void addEditorActions(MenuManager manager) {
+		final TextViewerAction copyAction = new TextViewerAction(viewer,
+				ITextOperationTarget.COPY);
+		copyAction.setText(UIText.SpellCheckingMessageArea_copy);
+		copyAction.setActionDefinitionId(IWorkbenchCommandConstants.EDIT_COPY);
+
+		final TextViewerAction selectAllAction = new TextViewerAction(viewer,
+				ITextOperationTarget.SELECT_ALL);
+		selectAllAction.setText(UIText.SpellCheckingMessageArea_selectAll);
+		selectAllAction
+				.setActionDefinitionId(IWorkbenchCommandConstants.EDIT_SELECT_ALL);
+
+		manager.add(copyAction);
+		manager.add(selectAllAction);
+		manager.add(new Separator());
+
+		viewer.addSelectionChangedListener(new ISelectionChangedListener() {
+
+			public void selectionChanged(SelectionChangedEvent event) {
+				copyAction.update();
+				selectAllAction.update();
+			}
+		});
+	}
+
+	/**
+	 * @see org.eclipse.ui.forms.editor.FormPage#createFormContent(org.eclipse.ui.forms.IManagedForm)
+	 */
+	protected void createFormContent(IManagedForm managedForm) {
+		Composite body = managedForm.getForm().getBody();
+		GridLayoutFactory.fillDefaults().numColumns(1).applyTo(body);
+
+		viewer = new DiffViewer(body, new CompositeRuler(), SWT.V_SCROLL
+				| SWT.H_SCROLL);
+		viewer.setEditable(false);
+		GridDataFactory.fillDefaults().grab(true, true)
+				.applyTo(viewer.getControl());
+
+		MenuManager manager = new MenuManager();
+		addEditorActions(manager);
+		Menu menu = manager.createContextMenu(viewer.getTextWidget());
+		IEditorSite site = getEditorSite();
+		site.setSelectionProvider(viewer);
+		site.registerContextMenu(
+				AbstractTextEditor.COMMON_EDITOR_CONTEXT_MENU_ID, manager,
+				viewer, true);
+		site.registerContextMenu(
+				AbstractTextEditor.DEFAULT_EDITOR_CONTEXT_MENU_ID, manager,
+				viewer, true);
+		viewer.getTextWidget().setMenu(menu);
+
+		formatDiff();
+	}
+}
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
index e1e1c9ba6a..77a854315b 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
@@ -854,6 +854,9 @@ DialogsPreferencePage_HomeDirWarning=&Home directory warning (Windows only)
 DialogsPreferencePage_RebaseCheckbox=&Rebase confirmation
 DialogsPreferencePage_ShowDialog=Prompt
 DialogsPreferencePage_ShowInitialConfigCheckbox=&Initial configuration
+DiffEditorPage_TaskGeneratingDiff=Generating diff
+DiffEditorPage_TaskUpdatingViewer=Updating diff viewer
+DiffEditorPage_Title=Diff
 DiscardChangesAction_confirmActionTitle=Discard Local Changes
 DiscardChangesAction_confirmActionMessage=This will discard all local changes for the selected resources. Untracked files will be ignored. Are you sure you want to do this?
 DiscardChangesAction_discardChanges=Discard Changes