Merge branch 'change-screen-deps'

* change-screen-deps:
  Add change level actions map to ChangeInfo
  Automatically refresh GWT UI on each page load
  Make parts of SubmitInfo and SubmitFailureDialog public
  Add no-arg constructor for CopyableLabel
  Fix visible length of CopyableLabel on Change-Id
  Support ListChangesOption in ChangeApi.detail() calls
  Add ChangeApi method to invoke rebase
  Add KeyDownHandler for escape to close popups
  Extract ReviewInput to top level class
  Add NativeMap.create() as a utility

Change-Id: Ic1cbc9fd51cde4a6b0fc748ce9488a9d2259f01b

Documentation/rest-api-changes.txt

@@ -2406,6 +2406,10 @@ Not set for merged changes.
 |`owner`              ||
 The owner of the change as an link:rest-api-accounts.html#account-info[
 AccountInfo] entity.
+|`actions`            |optional|
+Actions the caller might be able to perform on this revision. The
+information is a map of view name to link:#action-info[ActionInfo]
+entities.
 |`labels`             |optional|
 The labels of the change as a map that maps the label names to
 link:#label-info[LabelInfo] entries. +
@@ -2886,12 +2890,12 @@ The `RevisionInfo` entity contains information about a patch set.
 Information about how to fetch this patch set. The fetch information is
 provided as a map that maps the protocol name ("`git`", "`http`",
 "`ssh`") to link:#fetch-info[FetchInfo] entities.
-|`commit`      ||The commit of the patch set as
+|`commit`      |optional|The commit of the patch set as
 link:#commit-info[CommitInfo] entity.
-|`files`       ||
+|`files`       |optional|
 The files of the patch set as a map that maps the file names to
 link:#file-info[FileInfo] entities.
-|`actions`     ||
+|`actions`     |optional|
 Actions the caller might be able to perform on this revision. The
 information is a map of view name to link:#action-info[ActionInfo]
 entities.

gerrit-gwtexpui/src/main/java/com/google/gwtexpui/clippy/client/CopyableLabel.java

@@ -71,6 +71,10 @@ public class CopyableLabel extends Composite implements HasText {
   private TextBox textBox;
   private Element swf;
 
+  public CopyableLabel() {
+    this("");
+  }
+
   /**
    * Create a new label
    *
@@ -117,7 +121,6 @@ public class CopyableLabel extends Composite implements HasText {
   public void setPreviewText(final String text) {
     if (textLabel != null) {
       textLabel.setText(text);
-      visibleLen = text.length();
     }
   }
 

gerrit-gwtexpui/src/main/java/com/google/gwtexpui/globalkey/client/GlobalKey.java

@@ -15,6 +15,8 @@
 package com.google.gwtexpui.globalkey.client;
 
 import com.google.gwt.event.dom.client.KeyCodes;
+import com.google.gwt.event.dom.client.KeyDownEvent;
+import com.google.gwt.event.dom.client.KeyDownHandler;
 import com.google.gwt.event.dom.client.KeyPressEvent;
 import com.google.gwt.event.dom.client.KeyPressHandler;
 import com.google.gwt.event.logical.shared.CloseEvent;
@@ -92,6 +94,14 @@ public class GlobalKey {
     active = new State(panel);
     active.add(new HidePopupPanelCommand(0, KeyCodes.KEY_ESCAPE, panel));
     panel.addCloseHandler(restoreGlobal);
+    panel.addDomHandler(new KeyDownHandler() {
+      @Override
+      public void onKeyDown(KeyDownEvent event) {
+        if (event.getNativeKeyCode() == KeyCodes.KEY_ESCAPE) {
+          panel.hide();
+        }
+      }
+    }, KeyDownEvent.getType());
   }
 
   public static HandlerRegistration addApplication(final Widget widget,

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeApi.java

@@ -16,10 +16,13 @@ package com.google.gerrit.client.changes;
 
 import com.google.gerrit.client.rpc.NativeString;
 import com.google.gerrit.client.rpc.RestApi;
+import com.google.gerrit.common.changes.ListChangesOption;
 import com.google.gerrit.reviewdb.client.PatchSet;
 import com.google.gwt.core.client.JavaScriptObject;
 import com.google.gwt.user.client.rpc.AsyncCallback;
 
+import java.util.EnumSet;
+
 /**
  * A collection of static methods which work on the Gerrit REST API for specific
  * changes.
@@ -62,7 +65,20 @@ public class ChangeApi {
   }
 
   public static void detail(int id, AsyncCallback<ChangeInfo> cb) {
-    call(id, "detail").get(cb);
+    detail(id).get(cb);
+  }
+
+  public static void detail(int id, EnumSet<ListChangesOption> options,
+      AsyncCallback<ChangeInfo> cb) {
+    RestApi call = detail(id);
+    if (!options.isEmpty()) {
+      ChangeList.addOptions(call, options);
+    }
+    call.get(cb);
+  }
+
+  private static RestApi detail(int id) {
+    return call(id, "detail");
   }
 
   public static RestApi revision(int id, String revision) {
@@ -100,6 +116,12 @@ public class ChangeApi {
     call(id, commit, "submit").post(in, cb);
   }
 
+  /** Rebase a revision onto the branch tip. */
+  public static void rebase(int id, String commit, AsyncCallback<ChangeInfo> cb) {
+    JavaScriptObject in = JavaScriptObject.createObject();
+    call(id, commit, "rebase").post(in, cb);
+  }
+
   private static class Input extends JavaScriptObject {
     final native void topic(String t) /*-{ if(t)this.topic=t; }-*/;
     final native void message(String m) /*-{ if(m)this.message=m; }-*/;

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ChangeList.java

@@ -66,7 +66,7 @@ public class ChangeList extends JsArray<ChangeInfo> {
     call.get(callback);
   }
 
-  static void addOptions(RestApi call, EnumSet<ListChangesOption> s) {
+  public static void addOptions(RestApi call, EnumSet<ListChangesOption> s) {
     call.addParameterRaw("O", Integer.toHexString(ListChangesOption.toBits(s)));
   }
 

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/PublishCommentScreen.java

@@ -36,7 +36,6 @@ import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Patch;
 import com.google.gerrit.reviewdb.client.PatchLineComment;
 import com.google.gerrit.reviewdb.client.PatchSet;
-import com.google.gwt.core.client.JavaScriptObject;
 import com.google.gwt.core.client.JsArrayString;
 import com.google.gwt.event.dom.client.ClickEvent;
 import com.google.gwt.event.dom.client.ClickHandler;
@@ -402,7 +401,6 @@ public class PublishCommentScreen extends AccountScreen implements
   private void onSend2(final boolean submit) {
     ReviewInput data = ReviewInput.create();
     data.message(ChangeApi.emptyToNull(message.getText().trim()));
-    data.init();
     for (final ValueRadioButton b : approvalButtons) {
       if (b.getValue()) {
         data.label(b.label.name(), b.parseValue());
@@ -432,23 +430,6 @@ public class PublishCommentScreen extends AccountScreen implements
         });
   }
 
-  private static class ReviewInput extends JavaScriptObject {
-    static ReviewInput create() {
-      return (ReviewInput) createObject();
-    }
-
-    final native void message(String m) /*-{ if(m)this.message=m; }-*/;
-    final native void label(String n, short v) /*-{ this.labels[n]=v; }-*/;
-    final native void init() /*-{
-      this.labels = {};
-      this.strict_labels = true;
-      this.drafts = 'PUBLISH';
-    }-*/;
-
-    protected ReviewInput() {
-    }
-  }
-
   private void submit() {
     ChangeApi.submit(patchSetId.getParentKey().get(), revision,
       new GerritCallback<SubmitInfo>() {

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/ReviewInput.java

@@ -0,0 +1,37 @@
+// Copyright (C) 2013 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.client.changes;
+
+import com.google.gwt.core.client.JavaScriptObject;
+
+public class ReviewInput extends JavaScriptObject {
+  public static ReviewInput create() {
+    ReviewInput r = createObject().cast();
+    r.init();
+    return r;
+  }
+
+  public final native void message(String m) /*-{ if(m)this.message=m; }-*/;
+  public final native void label(String n, short v) /*-{ this.labels[n]=v; }-*/;
+
+  private final native void init() /*-{
+    this.labels = {};
+    this.strict_labels = true;
+    this.drafts = 'PUBLISH';
+  }-*/;
+
+  protected ReviewInput() {
+  }
+}

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/SubmitFailureDialog.java

@@ -18,13 +18,13 @@ import com.google.gerrit.client.ErrorDialog;
 import com.google.gwtexpui.safehtml.client.SafeHtmlBuilder;
 import com.google.gwtjsonrpc.client.RemoteJsonException;
 
-class SubmitFailureDialog extends ErrorDialog {
+public class SubmitFailureDialog extends ErrorDialog {
-  static boolean isConflict(Throwable err) {
+  public static boolean isConflict(Throwable err) {
     return err instanceof RemoteJsonException
         && 409 == ((RemoteJsonException) err).getCode();
   }
 
-  SubmitFailureDialog(String msg) {
+  public SubmitFailureDialog(String msg) {
     super(new SafeHtmlBuilder().append(msg.trim()).wikify());
     setText(Util.C.submitFailed());
   }

gerrit-gwtui/src/main/java/com/google/gerrit/client/changes/SubmitInfo.java

@@ -17,7 +17,7 @@ package com.google.gerrit.client.changes;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gwt.core.client.JavaScriptObject;
 
-class SubmitInfo extends JavaScriptObject {
+public class SubmitInfo extends JavaScriptObject {
   final Change.Status status() {
     return Change.Status.valueOf(statusRaw());
   }

gerrit-gwtui/src/main/java/com/google/gerrit/client/rpc/NativeMap.java

@@ -22,6 +22,10 @@ import java.util.Set;
 
 /** A map of native JSON objects, keyed by a string. */
 public class NativeMap<T extends JavaScriptObject> extends JavaScriptObject {
+  public static <T extends JavaScriptObject> NativeMap<T> create() {
+    return createObject().cast();
+  }
+
   /**
    * Loop through the result map's entries and copy the key strings into the
    * "name" property of the corresponding child object. This only runs on the

gerrit-pgm/src/main/java/com/google/gerrit/pgm/http/jetty/JettyServer.java

@@ -77,6 +77,12 @@ import java.util.zip.ZipFile;
 
 import javax.servlet.DispatcherType;
 import javax.servlet.Filter;
+import javax.servlet.FilterChain;
+import javax.servlet.FilterConfig;
+import javax.servlet.ServletException;
+import javax.servlet.ServletRequest;
+import javax.servlet.ServletResponse;
+import javax.servlet.http.HttpServletRequest;
 
 @Singleton
 public class JettyServer {
@@ -343,7 +349,7 @@ public class JettyServer {
     // need to unpack them into yet another temporary directory prior to
     // serving to clients.
     //
-    app.setBaseResource(getBaseResource());
+    app.setBaseResource(getBaseResource(app));
 
     // HTTP front-end filter to be used as surrogate of Apache HTTP
     // reverse-proxy filtering.
@@ -397,13 +403,14 @@ public class JettyServer {
     return app;
   }
 
-  private Resource getBaseResource() throws IOException {
+  private Resource getBaseResource(ServletContextHandler app)
+      throws IOException {
     if (baseResource == null) {
       try {
         baseResource = unpackWar(GerritLauncher.getDistributionArchive());
       } catch (FileNotFoundException err) {
         if (err.getMessage() == GerritLauncher.NOT_ARCHIVED) {
-          baseResource = useDeveloperBuild();
+          baseResource = useDeveloperBuild(app);
         } else {
           throw err;
         }
@@ -412,7 +419,13 @@ public class JettyServer {
     return baseResource;
   }
 
-  private Resource unpackWar(File srcwar) throws IOException {
+  private static Resource unpackWar(File srcwar) throws IOException {
+    File dstwar = makeWarTempDir();
+    unpack(srcwar, dstwar);
+    return Resource.newResource(dstwar.toURI());
+  }
+
+  private static File makeWarTempDir() throws IOException {
     // Obtain our local temporary directory, but it comes back as a file
     // so we have to switch it to be a directory post creation.
     //
@@ -425,11 +438,13 @@ public class JettyServer {
     // a security feature. Try to resolve out any symlinks in the path.
     //
     try {
-      dstwar = dstwar.getCanonicalFile();
+      return dstwar.getCanonicalFile();
     } catch (IOException e) {
-      dstwar = dstwar.getAbsoluteFile();
+      return dstwar.getAbsoluteFile();
     }
+  }
 
+  private static void unpack(File srcwar, File dstwar) throws IOException {
     final ZipFile zf = new ZipFile(srcwar);
     try {
       final Enumeration<? extends ZipEntry> e = zf.entries();
@@ -466,11 +481,9 @@ public class JettyServer {
     } finally {
       zf.close();
     }
-
-    return Resource.newResource(dstwar.toURI());
   }
 
-  private void mkdir(final File dir) throws IOException {
+  private static void mkdir(File dir) throws IOException {
     if (!dir.isDirectory()) {
       mkdir(dir.getParentFile());
       if (!dir.mkdir())
@@ -479,7 +492,8 @@ public class JettyServer {
     }
   }
 
-  private Resource useDeveloperBuild() throws IOException {
+  private Resource useDeveloperBuild(ServletContextHandler app)
+      throws IOException {
     // Find ourselves in the CLASSPATH. We should be a loose class file.
     //
     URL u = getClass().getResource(getClass().getSimpleName() + ".class");
@@ -510,12 +524,44 @@ public class JettyServer {
     dir = dir.getParentFile(); // pop classes
 
     if ("buck-out".equals(dir.getName())) {
+      final File dstwar = makeWarTempDir();
       String pkg = "gerrit-gwtui";
       String target = targetForBrowser(System.getProperty("gerrit.browser"));
-      File gen = new File(dir, "gen");
+      final File gen = new File(dir, "gen");
       String out = new File(new File(gen, pkg), target).getAbsolutePath();
-      build(dir.getParentFile(), gen, "//" + pkg + ":" + target);
+      final File zip = new File(out + ".zip");
-      return unpackWar(new File(out + ".zip"));
+      final File root = dir.getParentFile();
+      final String name = "//" + pkg + ":" + target;
+
+      File ui = new File(dstwar, "gerrit_ui");
+      File p = new File(ui, "permutations");
+      mkdir(ui);
+      p.createNewFile();
+      p.deleteOnExit();
+
+      app.addFilter(new FilterHolder(new Filter() {
+        private long last;
+
+        @Override
+        public void doFilter(ServletRequest request, ServletResponse res,
+            FilterChain chain) throws IOException, ServletException {
+          HttpServletRequest req = (HttpServletRequest) request;
+          build(root, gen, name);
+          if (last != zip.lastModified()) {
+            last = zip.lastModified();
+            unpack(zip, dstwar);
+          }
+          chain.doFilter(req, res);
+        }
+
+        @Override
+        public void init(FilterConfig config) {
+        }
+        @Override
+        public void destroy() {
+        }
+      }), "/", EnumSet.of(DispatcherType.REQUEST));
+      return Resource.newResource(dstwar.toURI());
     } else if ("target".equals(dir.getName())) {
       return useMavenDeveloperBuild(dir);
     } else {

gerrit-server/src/main/java/com/google/gerrit/server/change/Abandon.java

@@ -21,6 +21,7 @@ import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.DefaultInput;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gerrit.extensions.webui.UiCommand;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.ChangeMessage;
 import com.google.gerrit.reviewdb.server.ReviewDb;
@@ -41,8 +42,11 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.Collections;
+import java.util.EnumSet;
+import java.util.Set;
 
-public class Abandon implements RestModifyView<ChangeResource, Input> {
+public class Abandon implements RestModifyView<ChangeResource, Input>,
+    UiCommand<ChangeResource> {
   private static final Logger log = LoggerFactory.getLogger(Abandon.class);
 
   private final ChangeHooks hooks;
@@ -128,6 +132,37 @@ public class Abandon implements RestModifyView<ChangeResource, Input> {
     return json.format(change);
   }
 
+  @Override
+  public Set<Place> getPlaces() {
+    return EnumSet.of(Place.PATCHSET_ACTION_PANEL);
+  }
+
+  @Override
+  public String getLabel(ChangeResource resource) {
+    return "Abandon";
+  }
+
+  @Override
+  public String getTitle(ChangeResource resource) {
+    return null;
+  }
+
+  @Override
+  public boolean isVisible(ChangeResource resource) {
+    return isEnabled(resource);
+  }
+
+  @Override
+  public boolean isEnabled(ChangeResource resource) {
+    return resource.getChange().getStatus().isOpen()
+        && resource.getControl().canAbandon();
+  }
+
+  @Override
+  public String getConfirmationMessage(ChangeResource resource) {
+    return null;
+  }
+
   private ChangeMessage newMessage(Input input, IdentifiedUser caller,
       Change change) throws OrmException {
     StringBuilder msg = new StringBuilder();

gerrit-server/src/main/java/com/google/gerrit/server/change/ChangeJson.java

@@ -47,6 +47,8 @@ import com.google.gerrit.common.data.Permission;
 import com.google.gerrit.common.data.PermissionRange;
 import com.google.gerrit.common.data.SubmitRecord;
 import com.google.gerrit.common.data.UiCommandDetail;
+import com.google.gerrit.extensions.registration.DynamicMap;
+import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.extensions.restapi.Url;
 import com.google.gerrit.extensions.webui.UiCommand;
 import com.google.gerrit.reviewdb.client.Account;
@@ -129,6 +131,7 @@ public class ChangeJson {
   private final AccountInfo.Loader.Factory accountLoaderFactory;
   private final Provider<String> urlProvider;
   private final Urls urls;
+  private final DynamicMap<RestView<ChangeResource>> changes;
   private final Revisions revisions;
 
   private ChangeControl.Factory changeControlUserFactory;
@@ -150,6 +153,7 @@ public class ChangeJson {
       AccountInfo.Loader.Factory ailf,
       @CanonicalWebUrl Provider<String> curl,
       Urls urls,
+      DynamicMap<RestView<ChangeResource>> changes,
       Revisions revisions) {
     this.db = db;
     this.labelNormalizer = ln;
@@ -162,6 +166,7 @@ public class ChangeJson {
     this.accountLoaderFactory = ailf;
     this.urlProvider = curl;
     this.urls = urls;
+    this.changes = changes;
     this.revisions = revisions;
 
     options = EnumSet.noneOf(ListChangesOption.class);
@@ -286,6 +291,15 @@ public class ChangeJson {
       }
     }
 
+    if (has(CURRENT_ACTIONS) && user instanceof IdentifiedUser) {
+      out.actions = Maps.newTreeMap();
+      for (UiCommandDetail c : UiCommands.from(
+          changes,
+          new ChangeResource(control(cd)),
+          EnumSet.of(UiCommand.Place.PATCHSET_ACTION_PANEL))) {
+        out.actions.put(c.id, new ActionInfo(c));
+      }
+    }
     lastControl = null;
     return out;
   }
@@ -870,6 +884,7 @@ public class ChangeJson {
 
     AccountInfo owner;
 
+    Map<String, ActionInfo> actions;
     Map<String, LabelInfo> labels;
     Map<String, Collection<String>> permitted_labels;
     Collection<AccountInfo> removable_reviewers;

gerrit-server/src/main/java/com/google/gerrit/server/change/PutTopic.java

@@ -19,9 +19,10 @@ import com.google.gerrit.common.ChangeHooks;
 import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.DefaultInput;
-import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
+import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gerrit.extensions.webui.UiCommand;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.ChangeMessage;
 import com.google.gerrit.reviewdb.server.ReviewDb;
@@ -35,8 +36,11 @@ import com.google.inject.Inject;
 import com.google.inject.Provider;
 
 import java.util.Collections;
+import java.util.EnumSet;
+import java.util.Set;
 
-class PutTopic implements RestModifyView<ChangeResource, Input> {
+class PutTopic implements RestModifyView<ChangeResource, Input>,
+    UiCommand<ChangeResource> {
   private final Provider<ReviewDb> dbProvider;
   private final ChangeIndexer indexer;
   private final ChangeHooks hooks;
@@ -113,4 +117,34 @@ class PutTopic implements RestModifyView<ChangeResource, Input> {
         ? Response.none()
         : newTopicName;
   }
+
+  @Override
+  public Set<Place> getPlaces() {
+    return EnumSet.of(Place.PATCHSET_ACTION_PANEL);
+  }
+
+  @Override
+  public String getLabel(ChangeResource resource) {
+    return "Edit Topic";
+  }
+
+  @Override
+  public String getTitle(ChangeResource resource) {
+    return null;
+  }
+
+  @Override
+  public boolean isVisible(ChangeResource resource) {
+    return isEnabled(resource);
+  }
+
+  @Override
+  public boolean isEnabled(ChangeResource resource) {
+    return resource.getControl().canEditTopicName();
+  }
+
+  @Override
+  public String getConfirmationMessage(ChangeResource resource) {
+    return null;
+  }
 }

gerrit-server/src/main/java/com/google/gerrit/server/change/Restore.java

@@ -20,6 +20,7 @@ import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.DefaultInput;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gerrit.extensions.webui.UiCommand;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Change.Status;
 import com.google.gerrit.reviewdb.client.ChangeMessage;
@@ -41,8 +42,11 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import java.util.Collections;
+import java.util.EnumSet;
+import java.util.Set;
 
-public class Restore implements RestModifyView<ChangeResource, Input> {
+public class Restore implements RestModifyView<ChangeResource, Input>,
+    UiCommand<ChangeResource> {
   private static final Logger log = LoggerFactory.getLogger(Restore.class);
 
   private final ChangeHooks hooks;
@@ -127,6 +131,37 @@ public class Restore implements RestModifyView<ChangeResource, Input> {
     return json.format(change);
   }
 
+  @Override
+  public Set<Place> getPlaces() {
+    return EnumSet.of(Place.PATCHSET_ACTION_PANEL);
+  }
+
+  @Override
+  public String getLabel(ChangeResource resource) {
+    return "Restore";
+  }
+
+  @Override
+  public String getTitle(ChangeResource resource) {
+    return null;
+  }
+
+  @Override
+  public boolean isVisible(ChangeResource resource) {
+    return isEnabled(resource);
+  }
+
+  @Override
+  public boolean isEnabled(ChangeResource resource) {
+    return resource.getChange().getStatus() == Change.Status.ABANDONED
+        && resource.getControl().canRestore();
+  }
+
+  @Override
+  public String getConfirmationMessage(ChangeResource resource) {
+    return null;
+  }
+
   private ChangeMessage newMessage(Input input, IdentifiedUser caller,
       Change change) throws OrmException {
     StringBuilder msg = new StringBuilder();

gerrit-server/src/main/java/com/google/gerrit/server/change/Revert.java

@@ -20,6 +20,7 @@ import com.google.gerrit.extensions.restapi.AuthException;
 import com.google.gerrit.extensions.restapi.BadRequestException;
 import com.google.gerrit.extensions.restapi.ResourceConflictException;
 import com.google.gerrit.extensions.restapi.RestModifyView;
+import com.google.gerrit.extensions.webui.UiCommand;
 import com.google.gerrit.reviewdb.client.Change;
 import com.google.gerrit.reviewdb.client.Change.Status;
 import com.google.gerrit.reviewdb.server.ReviewDb;
@@ -40,7 +41,11 @@ import com.google.inject.Provider;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Repository;
 
-public class Revert implements RestModifyView<ChangeResource, Input> {
+import java.util.EnumSet;
+import java.util.Set;
+
+public class Revert implements RestModifyView<ChangeResource, Input>,
+    UiCommand<ChangeResource> {
   private final ChangeHooks hooks;
   private final RevertedSender.Factory revertedSenderFactory;
   private final CommitValidators.Factory commitValidatorsFactory;
@@ -107,6 +112,37 @@ public class Revert implements RestModifyView<ChangeResource, Input> {
     }
   }
 
+  @Override
+  public Set<Place> getPlaces() {
+    return EnumSet.of(Place.PATCHSET_ACTION_PANEL);
+  }
+
+  @Override
+  public String getLabel(ChangeResource resource) {
+    return "Revert";
+  }
+
+  @Override
+  public String getTitle(ChangeResource resource) {
+    return null;
+  }
+
+  @Override
+  public boolean isVisible(ChangeResource resource) {
+    return isEnabled(resource);
+  }
+
+  @Override
+  public boolean isEnabled(ChangeResource resource) {
+    return resource.getChange().getStatus() == Change.Status.MERGED
+        && resource.getControl().getRefControl().canUpload();
+  }
+
+  @Override
+  public String getConfirmationMessage(ChangeResource resource) {
+    return null;
+  }
+
   private static String status(Change change) {
     return change != null ? change.getStatus().name().toLowerCase() : "deleted";
    }

gerrit-server/src/main/java/com/google/gerrit/server/extensions/webui/UiCommands.java

@@ -22,7 +22,7 @@ import com.google.common.collect.Lists;
 import com.google.common.collect.Sets;
 import com.google.gerrit.common.data.UiCommandDetail;
 import com.google.gerrit.extensions.registration.DynamicMap;
-import com.google.gerrit.extensions.restapi.ChildCollection;
+import com.google.gerrit.extensions.restapi.RestCollection;
 import com.google.gerrit.extensions.restapi.RestResource;
 import com.google.gerrit.extensions.restapi.RestView;
 import com.google.gerrit.extensions.webui.UiCommand;
@@ -71,7 +71,7 @@ public class UiCommands {
   }
 
   public static <R extends RestResource> Iterable<UiCommandDetail> from(
-      ChildCollection<?, R> collection,
+      RestCollection<?, R> collection,
       R resource,
       EnumSet<UiCommand.Place> places) {
     return from(collection.views(), resource, places);