Fix QuickOutline command in DiffEditor

1. To make the command and its key binding show up in the key bindings
   preference page, the command needs to have a category.
2. To make the texts displayed in that preference page make sense, the
   command must have a sensible description.
3. The command name should just be "Quick Outline" similar to the other
   commands from Java, Mylyn, or PDE.
4. The context "org.eclipse.egit.ui.DiffViewer" for the keybinding must
   be a child of textEditorScope, otherwise there can be key conflicts.
   (For instance, lsp4e uses M1+O in the textEditorScope for "Go to
   Symbol in File". With our binding in the window-wide context, this
   conflicts. With our binding in a child of textEditorScope, it won't
   conflict but override.)
5. The DiffEditor must set the "org.eclipse.egit.ui.DiffViewer" context.

Bug: 563986
Change-Id: I08f549ddf038a2d1b9520cf75d99bc596241df16
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

3 files changed, 16 insertions, 6 deletions

diff --git a/org.eclipse.egit.ui/plugin.properties b/org.eclipse.egit.ui/plugin.properties
index 57acf34458..bebed97a19 100644
--- a/org.eclipse.egit.ui/plugin.properties
+++ b/org.eclipse.egit.ui/plugin.properties
@@ -395,7 +395,8 @@ BranchNameProviderExtension-point.name = BranchNameProvider
 ShowInSystemExplorerCommand.name = Show In System Explorer
 ShowUnifiedDiffCommand.name = Show Unified Diff
 DiffViewerContext = In Diff Viewer
-UnifiedDiffQuickOutlineCommand.name = Show Quick Outline
+UnifiedDiffQuickOutlineCommand.name = Quick Outline
+UnifiedDiffQuickOutlineCommand.description = Show the quick outline for a unified diff
 
 FetchFromGerritCommand.name = Fetch From Gerrit
 FetchFromGerritCommand.label = Fetch from &Gerrit...
diff --git a/org.eclipse.egit.ui/plugin.xml b/org.eclipse.egit.ui/plugin.xml
index 097453aae6..8043b94b3d 100644
--- a/org.eclipse.egit.ui/plugin.xml
+++ b/org.eclipse.egit.ui/plugin.xml
@@ -1160,6 +1160,12 @@
             id="org.eclipse.egit.ui.team.Revert"
             name="%RevertCommand.name">
       </command>
+      <command
+            categoryId="org.eclipse.egit.ui.commandCategory"
+            id="org.eclipse.egit.ui.commit.DiffEditorQuickOutlineCommand"
+            name="%UnifiedDiffQuickOutlineCommand.name"
+            description="%UnifiedDiffQuickOutlineCommand.description">
+      </command>
    </extension>
    <extension
          point="org.eclipse.ui.handlers">
@@ -7241,10 +7247,6 @@
             id="org.eclipse.egit.ui.commit.UnifiedDiffCommand"
             name="%ShowUnifiedDiffCommand.name">
       </command>
-      <command
-            id="org.eclipse.egit.ui.commit.DiffEditorQuickOutlineCommand"
-            name="%UnifiedDiffQuickOutlineCommand.name">
-      </command>
    </extension>
    <extension
          name="%CommitViewerCommands.extension.name"
@@ -7292,7 +7294,7 @@
       <context
             id="org.eclipse.egit.ui.DiffViewer"
             name="%DiffViewerContext"
-            parentId="org.eclipse.ui.contexts.window">
+            parentId="org.eclipse.ui.textEditorScope">
       </context>
    </extension>
    <extension
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffEditor.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffEditor.java
index 58fa42be25..98201daf53 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffEditor.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/commit/DiffEditor.java
@@ -116,6 +116,8 @@ public class DiffEditor extends TextEditor
 	/** External ID used in plugin.xml for this stand-alone editor. */
 	public static final String EDITOR_ID = "org.eclipse.egit.ui.diffEditor"; //$NON-NLS-1$
 
+	private static final String CONTEXT_ID = "org.eclipse.egit.ui.DiffViewer"; //$NON-NLS-1$
+
 	private static final String ADD_ANNOTATION_TYPE = "org.eclipse.egit.ui.commitEditor.diffAdded"; //$NON-NLS-1$
 
 	private static final String REMOVE_ANNOTATION_TYPE = "org.eclipse.egit.ui.commitEditor.diffRemoved"; //$NON-NLS-1$
@@ -283,6 +285,11 @@ public class DiffEditor extends TextEditor
 	}
 
 	@Override
+	protected void initializeKeyBindingScopes() {
+		setKeyBindingScopes(new String[] { CONTEXT_ID });
+	}
+
+	@Override
 	protected IVerticalRulerColumn createLineNumberRulerColumn() {
 		lineNumberColumn = new OldNewLogicalLineNumberRulerColumn(
 				plainLineNumbers);