ChangeScreen: Highlight selected outdated patch set

Gives a visual hint when the currently viewed patch set is not the
latest one.

An example use-case is when change A depends on some previous patch set
of change B. Clicking change B in the Related Changes tab opens the
dependent patch set, but usually the latest PS is what interests the
user.

The color used for this indication is the same as the marker color for
not current patch sets in Related Changes.

Change-Id: If7d1e673172a44ba1c5ef9aea332d8fc54b1125c

Documentation/user-review-ui.txt

@@ -391,6 +391,10 @@ operations are only available on the current patch set.
 
 image::images/user-review-ui-change-screen-patch-sets.png[width=800, link="images/user-review-ui-change-screen-patch-sets.png"]
 
+Another indication is a highlighted drop-down label.
+
+image::images/user-review-ui-change-screen-not-current.png[width=800, link="images/user-review-ui-change-screen-not-current.png"]
+
 [[patch-set-drop-down]]
 The patch set drop-down list shows the list of patch sets and allows to
 switch between them. The patch sets are sorted in descending order so

gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.java

@@ -126,6 +126,7 @@ public class ChangeScreen extends Screen {
     String pushCertStatus();
     String replyBox();
     String selected();
+    String notCurrentPatchSet();
   }
 
   static ChangeScreen get(NativeEvent in) {
@@ -416,6 +417,14 @@ public class ChangeScreen extends Screen {
     }
   }
 
+  private void updatePatchSetsTextStyle(boolean isPatchSetCurrent) {
+    if (isPatchSetCurrent) {
+      patchSetsText.removeClassName(style.notCurrentPatchSet());
+    } else {
+      patchSetsText.addClassName(style.notCurrentPatchSet());
+    }
+  }
+
   private void initRevisionsAction(ChangeInfo info, String revision,
       NativeMap<ActionInfo> actions) {
     int currentPatchSet;
@@ -429,16 +438,22 @@ public class ChangeScreen extends Screen {
     }
 
     String currentlyViewedPatchSet;
-    if (info.revision(revision).id().equals("edit")) {
+    boolean isPatchSetCurrent = true;
+    String revisionId = info.revision(revision).id();
+    if (revisionId.equals("edit")) {
       currentlyViewedPatchSet =
           Resources.M.editPatchSet(RevisionInfo.findEditParent(info.revisions()
               .values()));
       currentPatchSet = info.revisions().values().length() - 1;
     } else {
-      currentlyViewedPatchSet = info.revision(revision).id();
+      currentlyViewedPatchSet = revisionId;
+      if (!currentlyViewedPatchSet.equals(Integer.toString(currentPatchSet))) {
+        isPatchSetCurrent = false;
+      }
     }
     patchSetsText.setInnerText(Resources.M.patchSets(
         currentlyViewedPatchSet, currentPatchSet));
+    updatePatchSetsTextStyle(isPatchSetCurrent);
     patchSetsAction = new PatchSetsAction(
         info.legacyId(), revision, edit,
         style, headerLine, patchSets);

gerrit-gwtui/src/main/java/com/google/gerrit/client/change/ChangeScreen.ui.xml

@@ -338,6 +338,10 @@ limitations under the License.
     .pushCertStatus {
       padding-left: 5px;
     }
+
+    .notCurrentPatchSet {
+      background-color: #FFA62F;
+    }
   </ui:style>
 
   <g:HTMLPanel styleName='{style.cs2}'>