History: show whitespace in the diff viewer

Give the diff viewer in the history view a little context menu, shown
only when there is actually some content. The context menu contains
copy, select all, and show whitespace. The latter enables the user to
switch on and off showing whitespace, and it makes the viewer respect
the global editor preference for showing whitespace.

Bug: 462509
Change-Id: Iad75ffb10d539f9913a85a6d1382bb6ef307511b
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

2 files changed, 40 insertions, 0 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/ShowWhitespaceAction.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/ShowWhitespaceAction.java
index dbdd042af9..6ce0acdfc3 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/ShowWhitespaceAction.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/dialogs/ShowWhitespaceAction.java
@@ -33,6 +33,16 @@ public class ShowWhitespaceAction extends TextEditorPropertyAction {
 	 *
 	 * @param viewer
 	 *            to operate on
+	 */
+	public ShowWhitespaceAction(ITextViewer viewer) {
+		this(viewer, false);
+	}
+
+	/**
+	 * Creates a new {@link ShowWhitespaceAction}.
+	 *
+	 * @param viewer
+	 *            to operate on
 	 * @param initiallyOff
 	 *            whether to show whitespace initially
 	 */
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java
index ee1deea7d2..8b99e743b5 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java
@@ -45,6 +45,7 @@ import org.eclipse.egit.ui.Activator;
 import org.eclipse.egit.ui.JobFamilies;
 import org.eclipse.egit.ui.UIPreferences;
 import org.eclipse.egit.ui.UIUtils;
+import org.eclipse.egit.ui.internal.ActionUtils;
 import org.eclipse.egit.ui.internal.CompareUtils;
 import org.eclipse.egit.ui.internal.UIIcons;
 import org.eclipse.egit.ui.internal.UIText;
@@ -55,6 +56,7 @@ import org.eclipse.egit.ui.internal.commit.FocusTracker;
 import org.eclipse.egit.ui.internal.components.RepositoryMenuUtil.RepositoryToolbarAction;
 import org.eclipse.egit.ui.internal.dialogs.HyperlinkSourceViewer;
 import org.eclipse.egit.ui.internal.dialogs.HyperlinkTokenScanner;
+import org.eclipse.egit.ui.internal.dialogs.ShowWhitespaceAction;
 import org.eclipse.egit.ui.internal.fetch.FetchHeadChangedEvent;
 import org.eclipse.egit.ui.internal.history.FindToolbar.StatusListener;
 import org.eclipse.egit.ui.internal.repository.tree.AdditionalRefNode;
@@ -90,6 +92,7 @@ import org.eclipse.jface.text.Document;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.ITextListener;
+import org.eclipse.jface.text.ITextOperationTarget;
 import org.eclipse.jface.text.TextAttribute;
 import org.eclipse.jface.text.TextEvent;
 import org.eclipse.jface.text.hyperlink.IHyperlinkDetector;
@@ -1290,6 +1293,33 @@ public class GitHistoryPage extends HistoryPage implements RefsChangedListener,
 		diffViewer.getControl().setLayoutData(
 				GridDataFactory.fillDefaults().grab(true, false).create());
 
+		ActionUtils.UpdateableAction selectAll = ActionUtils.createGlobalAction(
+				ActionFactory.SELECT_ALL,
+				() -> diffViewer.doOperation(ITextOperationTarget.SELECT_ALL),
+				() -> diffViewer
+						.canDoOperation(ITextOperationTarget.SELECT_ALL));
+		ActionUtils.UpdateableAction copy = ActionUtils.createGlobalAction(
+				ActionFactory.COPY,
+				() -> diffViewer.doOperation(ITextOperationTarget.COPY),
+				() -> diffViewer.canDoOperation(ITextOperationTarget.COPY));
+		ActionUtils.setGlobalActions(diffViewer.getControl(), copy, selectAll);
+		ShowWhitespaceAction showWhitespaceAction = new ShowWhitespaceAction(
+				diffViewer);
+		diffViewer.addSelectionChangedListener(e -> copy.update());
+		MenuManager contextMenu = new MenuManager();
+		contextMenu.setRemoveAllWhenShown(true);
+		contextMenu.addMenuListener(manager -> {
+			if (diffViewer.getDocument().getLength() > 0) {
+				manager.add(copy);
+				manager.add(selectAll);
+				manager.add(new Separator());
+				manager.add(showWhitespaceAction);
+			}
+		});
+		StyledText diffWidget = diffViewer.getTextWidget();
+		diffWidget.setMenu(contextMenu.createContextMenu(diffWidget));
+		diffWidget.addDisposeListener(e -> showWhitespaceAction.dispose());
+
 		setWrap(store
 				.getBoolean(UIPreferences.RESOURCEHISTORY_SHOW_COMMENT_WRAP));