diff --git a/BUCK b/BUCK
index b28f661..081ad6f 100644
--- a/BUCK
+++ b/BUCK
@@ -20,6 +20,8 @@
 java_test(
   name = 'cookbook_tests',
   srcs = glob(['src/test/java/**/*.java']),
+  labels = ['cookbook-plugin'],
+  source_under_test = [':cookbook-plugin__plugin'],
   deps = [
     ':cookbook-plugin__plugin',
     '//lib:junit',
diff --git a/lib/gerrit/BUCK b/lib/gerrit/BUCK
index 3d891ea..ee02ebb 100644
--- a/lib/gerrit/BUCK
+++ b/lib/gerrit/BUCK
@@ -1,7 +1,7 @@
 include_defs('//bucklets/maven_jar.bucklet')
 
-VER = '2.11'
-REPO = MAVEN_CENTRAL
+VER = '2.12-SNAPSHOT'
+REPO = MAVEN_LOCAL
 
 maven_jar(
   name = 'plugin-api',
diff --git a/pom.xml b/pom.xml
index 5280bc9..b7ff1cc 100644
--- a/pom.xml
+++ b/pom.xml
@@ -22,7 +22,7 @@
   <groupId>com.googlesource.gerrit.plugins</groupId>
   <artifactId>cookbook-plugin</artifactId>
   <packaging>jar</packaging>
-  <version>2.11</version>
+  <version>2.12-SNAPSHOT</version>
   <properties>
     <Gerrit-ApiType>plugin</Gerrit-ApiType>
     <Gerrit-ApiVersion>${project.version}</Gerrit-ApiVersion>
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/CommitValidator.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/CommitValidator.java
new file mode 100644
index 0000000..9bc6f5d
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/CommitValidator.java
@@ -0,0 +1,38 @@
+// Copyright (C) 2015 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.googlesource.gerrit.plugins.cookbook;
+
+import com.google.common.collect.ImmutableList;
+import com.google.gerrit.server.events.CommitReceivedEvent;
+import com.google.gerrit.server.git.validators.CommitValidationException;
+import com.google.gerrit.server.git.validators.CommitValidationListener;
+import com.google.gerrit.server.git.validators.CommitValidationMessage;
+
+import java.util.List;
+
+public class CommitValidator implements CommitValidationListener {
+  @Override
+  public List<CommitValidationMessage> onCommitReceived(
+      CommitReceivedEvent receiveEvent) throws CommitValidationException {
+    if ("plugins/cookbook".equals(receiveEvent.project.getName()) &&
+        !receiveEvent.commit.getShortMessage().startsWith("Cookbook: ")) {
+      CommitValidationMessage m = new CommitValidationMessage(
+          "Subject should begin with 'Cookbook: '", true);
+      throw new CommitValidationException(
+          "Invalid commit message", ImmutableList.of(m));
+    }
+    return ImmutableList.of();
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/Greetings.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/Greetings.java
index 58a9017..f53b066 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/cookbook/Greetings.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/Greetings.java
@@ -17,17 +17,12 @@
 import com.google.gerrit.extensions.restapi.Response;
 import com.google.gerrit.extensions.restapi.RestReadView;
 import com.google.gerrit.server.change.RevisionResource;
-import com.google.inject.Inject;
 
 import java.util.ArrayList;
 import java.util.Collection;
 
 class Greetings implements RestReadView<RevisionResource> {
 
-  @Inject
-  Greetings() {
-  }
-
   @Override
   public Response<Collection<GreetInfo>> apply(RevisionResource rev) {
     Collection<GreetInfo> l = new ArrayList<>(3);
@@ -40,7 +35,7 @@
     return Response.ok(l);
   }
 
-  class GreetInfo {
+  static class GreetInfo {
     String message;
     String country;
     String href;
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/Module.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/Module.java
index 2d09990..e2689b9 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/cookbook/Module.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/Module.java
@@ -29,6 +29,7 @@
 import com.google.gerrit.extensions.webui.ProjectWebLink;
 import com.google.gerrit.extensions.webui.TopMenu;
 import com.google.gerrit.server.config.ProjectConfigEntry;
+import com.google.gerrit.server.git.validators.CommitValidationListener;
 import com.google.gerrit.server.git.validators.MergeValidationListener;
 import com.google.gerrit.server.git.validators.UploadValidationListener;
 import com.google.gerrit.server.plugins.ServerPluginProvider;
@@ -64,6 +65,8 @@
         .to(MergeUserValidator.class);
     DynamicSet.bind(binder(), HashtagValidationListener.class)
         .to(HashtagValidator.class);
+    DynamicSet.bind(binder(), CommitValidationListener.class)
+        .to(CommitValidator.class);
     DynamicSet.bind(binder(), NewProjectCreatedListener.class)
         .to(ProjectCreatedListener.class);
     configurePluginParameters();
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/BuildsDropDownPanel.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/BuildsDropDownPanel.java
new file mode 100644
index 0000000..86b7034
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/BuildsDropDownPanel.java
@@ -0,0 +1,74 @@
+// Copyright (C) 2015 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.googlesource.gerrit.plugins.cookbook.client;
+
+import com.google.gerrit.plugin.client.extension.Panel;
+import com.google.gwt.user.client.ui.FlowPanel;
+import com.google.gwt.user.client.ui.Grid;
+import com.google.gwt.user.client.ui.HTMLTable.CellFormatter;
+import com.google.gwt.user.client.ui.HorizontalPanel;
+import com.google.gwt.user.client.ui.Image;
+import com.google.gwt.user.client.ui.InlineHyperlink;
+import com.google.gwt.user.client.ui.InlineLabel;
+
+/**
+ * Extension for change screen that displays a status in the header bar.
+ */
+public class BuildsDropDownPanel extends FlowPanel {
+  static class Factory implements Panel.EntryPoint {
+    @Override
+    public void onLoad(Panel panel) {
+      panel.setWidget(new BuildsDropDownPanel());
+    }
+  }
+
+  BuildsDropDownPanel() {
+    Grid g = new Grid(3, 4);
+    g.addStyleName("infoBlock");
+    CellFormatter fmt = g.getCellFormatter();
+
+    g.setText(0, 0, "State");
+    fmt.addStyleName(0, 0, "header");
+    g.setText(0, 1, "PS");
+    fmt.addStyleName(0, 1, "header");
+    g.setText(0, 2, "Date");
+    fmt.addStyleName(0, 2, "header");
+    g.setText(0, 3, "Log");
+    fmt.addStyleName(0, 3, "header");
+
+    HorizontalPanel p = new HorizontalPanel();
+    p.add(new Image(CookBookPlugin.RESOURCES.greenCheck()));
+    p.add(new InlineLabel("OK"));
+    g.setWidget(1, 0, p);
+    g.setWidget(1, 1, new InlineLabel("2"));
+    g.setWidget(1, 2, new InlineLabel("2015-07-09 11:06:13"));
+    g.setWidget(1, 3, new InlineHyperlink("Build Log", "TODO"));
+
+    p = new HorizontalPanel();
+    p.add(new Image(CookBookPlugin.RESOURCES.redNot()));
+    p.add(new InlineLabel("FAILED"));
+    g.setWidget(2, 0, p);
+    g.setWidget(2, 1, new InlineLabel("1"));
+    g.setWidget(2, 2, new InlineLabel("2015-07-09 09:17:28"));
+    g.setWidget(2, 3, new InlineHyperlink("Build Log", "TODO"));
+
+    fmt.addStyleName(0, 0, "topmost");
+    fmt.addStyleName(0, 1, "topmost");
+    fmt.addStyleName(0, 2, "topmost");
+    fmt.addStyleName(0, 3, "topmost");
+
+    add(new PopDownButton("Builds", g));
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/ChangeScreenStatusExtension.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/ChangeScreenStatusExtension.java
new file mode 100644
index 0000000..e0ceeed
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/ChangeScreenStatusExtension.java
@@ -0,0 +1,39 @@
+// Copyright (C) 2015 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.googlesource.gerrit.plugins.cookbook.client;
+
+import com.google.gerrit.plugin.client.extension.Panel;
+import com.google.gwt.dom.client.Style.Unit;
+import com.google.gwt.user.client.ui.FlowPanel;
+import com.google.gwt.user.client.ui.Image;
+import com.google.gwt.user.client.ui.InlineLabel;
+
+/**
+ * Extension for change screen that displays a status in the header bar.
+ */
+public class ChangeScreenStatusExtension extends FlowPanel {
+  static class Factory implements Panel.EntryPoint {
+    @Override
+    public void onLoad(Panel panel) {
+      panel.setWidget(new ChangeScreenStatusExtension());
+    }
+  }
+
+  ChangeScreenStatusExtension() {
+    getElement().getStyle().setPadding(5, Unit.PX);
+    add(new Image(CookBookPlugin.RESOURCES.greenCheck()));
+    add(new InlineLabel("OK"));
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookChangeScreenExtension.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookChangeScreenExtension.java
new file mode 100644
index 0000000..faf4c0e
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookChangeScreenExtension.java
@@ -0,0 +1,54 @@
+// Copyright (C) 2015 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.googlesource.gerrit.plugins.cookbook.client;
+
+import com.google.gerrit.client.GerritUiExtensionPoint;
+import com.google.gerrit.client.info.ChangeInfo;
+import com.google.gerrit.plugin.client.extension.Panel;
+import com.google.gwt.user.client.ui.Grid;
+import com.google.gwt.user.client.ui.VerticalPanel;
+import com.google.gwt.user.client.ui.HTMLTable.CellFormatter;
+import com.google.gwtexpui.clippy.client.CopyableLabel;
+
+/**
+ * Extension for change screen that displays the numeric change ID with
+ * copy-to-clipboard icon.
+ */
+public class CookBookChangeScreenExtension extends VerticalPanel {
+  static class Factory implements Panel.EntryPoint {
+    @Override
+    public void onLoad(Panel panel) {
+      panel.setWidget(new CookBookChangeScreenExtension(panel));
+    }
+  }
+
+  CookBookChangeScreenExtension(Panel panel) {
+    ChangeInfo change =
+        panel.getObject(GerritUiExtensionPoint.Key.CHANGE_INFO).cast();
+
+    Grid g = new Grid(1, 2);
+    g.addStyleName("infoBlock");
+    CellFormatter fmt = g.getCellFormatter();
+
+    g.setText(0, 0, "Numeric Change ID");
+    fmt.addStyleName(0, 0, "header");
+    g.setWidget(0, 1, new CopyableLabel(Integer.toString(change._number())));
+    add(g);
+
+    fmt.addStyleName(0, 0, "topmost");
+    fmt.addStyleName(0, 1, "topmost");
+    fmt.addStyleName(0, 0, "bottomheader");
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookPlugin.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookPlugin.java
index e9ace38..7a56ca0 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookPlugin.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookPlugin.java
@@ -14,12 +14,49 @@
 
 package com.googlesource.gerrit.plugins.cookbook.client;
 
+import com.google.gerrit.client.GerritUiExtensionPoint;
+import com.google.gerrit.client.Resources;
 import com.google.gerrit.plugin.client.Plugin;
 import com.google.gerrit.plugin.client.PluginEntryPoint;
+import com.google.gerrit.plugin.client.extension.Panel;
+import com.google.gwt.core.client.GWT;
+import com.google.gwt.event.dom.client.ClickEvent;
+import com.google.gwt.event.dom.client.ClickHandler;
+import com.google.gwt.user.client.Window;
+import com.google.gwt.user.client.ui.Button;
 
 public class CookBookPlugin extends PluginEntryPoint {
+  public static final Resources RESOURCES = GWT.create(Resources.class);
+
   @Override
   public void onPluginLoad() {
     Plugin.get().screen("", new IndexScreen.Factory());
+    Plugin.get().settingsScreen("preferences", "Food Preferences",
+        new FoodPreferencesScreen.Factory());
+    Plugin.get().panel(GerritUiExtensionPoint.PROFILE_SCREEN_BOTTOM,
+        new CookBookProfileExtension.Factory());
+    Plugin.get().panel(
+        GerritUiExtensionPoint.CHANGE_SCREEN_BELOW_CHANGE_INFO_BLOCK,
+        new CookBookChangeScreenExtension.Factory());
+    Plugin.get().panel(GerritUiExtensionPoint.CHANGE_SCREEN_HEADER,
+        new ChangeScreenStatusExtension.Factory());
+    Plugin.get().panel(
+        GerritUiExtensionPoint.CHANGE_SCREEN_HEADER_RIGHT_OF_POP_DOWNS,
+        new BuildsDropDownPanel.Factory());
+    Plugin.get().panel(
+        GerritUiExtensionPoint.CHANGE_SCREEN_HEADER_RIGHT_OF_BUTTONS,
+        new Panel.EntryPoint() {
+          @Override
+          public void onLoad(Panel panel) {
+            Button b = new HighlightButton("Library-Compliance+1");
+            b.addClickHandler(new ClickHandler() {
+              @Override
+              public void onClick(ClickEvent event) {
+                Window.alert("TODO");
+              }
+            });
+            panel.setWidget(b);
+          }
+        });
   }
 }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookProfileExtension.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookProfileExtension.java
new file mode 100644
index 0000000..e50427a
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/CookBookProfileExtension.java
@@ -0,0 +1,65 @@
+// Copyright (C) 2015 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.googlesource.gerrit.plugins.cookbook.client;
+
+import com.google.gerrit.client.GerritUiExtensionPoint;
+import com.google.gerrit.client.info.AccountInfo;
+import com.google.gerrit.plugin.client.extension.Panel;
+import com.google.gwt.user.client.ui.Grid;
+import com.google.gwt.user.client.ui.HTMLTable.CellFormatter;
+import com.google.gwt.user.client.ui.VerticalPanel;
+
+/**
+ * Extension for the user profile screen.
+ */
+public class CookBookProfileExtension extends VerticalPanel {
+  static class Factory implements Panel.EntryPoint {
+    @Override
+    public void onLoad(Panel panel) {
+      AccountInfo accountInfo =
+          panel.getObject(GerritUiExtensionPoint.Key.ACCOUNT_INFO).cast();
+      panel.setWidget(new CookBookProfileExtension(accountInfo));
+    }
+  }
+
+  CookBookProfileExtension(AccountInfo accountInfo) {
+    Grid g = new Grid(3, 2);
+    g.addStyleName("infoBlock");
+    g.addStyleName("accountInfoBlock");
+    CellFormatter fmt = g.getCellFormatter();
+
+    // TODO: fetch employer and department via REST from server,
+    // e.g. GET /accounts/self/cookbook~info
+
+    g.setText(0, 0, "Employer");
+    fmt.addStyleName(0, 0, "header");
+    g.setText(0, 1, "CookBook Corporation");
+
+    g.setText(1, 0, "Department");
+    fmt.addStyleName(1, 0, "header");
+    g.setText(1, 1, "Cookies " + accountInfo.email());
+
+    g.setText(2, 0, "CookBook Email");
+    fmt.addStyleName(2, 0, "header");
+    g.setText(2, 1, accountInfo.username() != null
+        ? accountInfo.username() + "@cookbook.com"
+        : "N/A");
+    add(g);
+
+    fmt.addStyleName(0, 0, "topmost");
+    fmt.addStyleName(0, 1, "topmost");
+    fmt.addStyleName(2, 0, "bottomheader");
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/FoodPreferencesScreen.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/FoodPreferencesScreen.java
new file mode 100644
index 0000000..6ba46fd
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/FoodPreferencesScreen.java
@@ -0,0 +1,67 @@
+// Copyright (C) 2015 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.googlesource.gerrit.plugins.cookbook.client;
+
+import com.google.gerrit.plugin.client.screen.Screen;
+import com.google.gwt.event.dom.client.ClickEvent;
+import com.google.gwt.event.dom.client.ClickHandler;
+import com.google.gwt.event.dom.client.KeyPressEvent;
+import com.google.gwt.event.dom.client.KeyPressHandler;
+import com.google.gwt.user.client.Window;
+import com.google.gwt.user.client.ui.Button;
+import com.google.gwt.user.client.ui.Label;
+import com.google.gwt.user.client.ui.Panel;
+import com.google.gwt.user.client.ui.TextArea;
+import com.google.gwt.user.client.ui.VerticalPanel;
+
+class FoodPreferencesScreen extends VerticalPanel {
+  static class Factory implements Screen.EntryPoint {
+    @Override
+    public void onLoad(Screen screen) {
+      screen.setPageTitle("Settings");
+      screen.show(new FoodPreferencesScreen());
+    }
+  }
+
+  FoodPreferencesScreen() {
+    setStyleName("cookbook-panel");
+
+    Panel messagePanel = new VerticalPanel();
+    messagePanel.add(new Label("Food Allergies or Dietary Concerns:"));
+    TextArea txt = new TextArea();
+    txt.addKeyPressHandler(new KeyPressHandler() {
+      @Override
+      public void onKeyPress(final KeyPressEvent event) {
+        event.stopPropagation();
+      }
+    });
+    txt.setVisibleLines(12);
+    txt.setCharacterWidth(80);
+    txt.getElement().setPropertyBoolean("spellcheck", false);
+    messagePanel.add(txt);
+    add(messagePanel);
+
+    Button helloButton = new Button("Save");
+    helloButton.addStyleName("cookbook-helloButton");
+    helloButton.addClickHandler(new ClickHandler() {
+      @Override
+      public void onClick(final ClickEvent event) {
+        Window.alert("TODO: implement save");
+      }
+    });
+    add(helloButton);
+    helloButton.setEnabled(true);
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/HighlightButton.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/HighlightButton.java
new file mode 100644
index 0000000..0af633f
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/HighlightButton.java
@@ -0,0 +1,36 @@
+// Copyright (C) 2015 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.googlesource.gerrit.plugins.cookbook.client;
+
+import com.google.gwt.user.client.ui.Button;
+import com.google.gwtexpui.safehtml.client.SafeHtmlBuilder;
+
+/**
+ * Highlight button for header line in change screen.
+ *
+ * This class can *only* be used within a panel that extends the header line of
+ * the change screen, but will not work standalone.
+ */
+public class HighlightButton extends Button {
+
+  public HighlightButton(String text) {
+    // Create Button with inner div. This is required to get proper styling
+    // in the context of the change screen.
+    super((new SafeHtmlBuilder()).openDiv()
+        .appendAttribute("style", "color: #fff;").append(text).closeDiv());
+    getElement().removeClassName("gwt-Button");
+    getElement().getStyle().setBackgroundColor("#4d90fe");
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/IndexScreen.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/IndexScreen.java
index 0edf949..774ec3d 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/IndexScreen.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/IndexScreen.java
@@ -14,9 +14,7 @@
 
 package com.googlesource.gerrit.plugins.cookbook.client;
 
-import com.google.gerrit.client.Resources;
 import com.google.gerrit.plugin.client.screen.Screen;
-import com.google.gwt.core.client.GWT;
 import com.google.gwt.core.client.Scheduler;
 import com.google.gwt.core.client.Scheduler.ScheduledCommand;
 import com.google.gwt.event.dom.client.ClickEvent;
@@ -45,14 +43,13 @@
 
   private TextBox usernameTxt;
   private TextArea greetingTxt;
-  private Resources RESOURCES = GWT.create(Resources.class);
 
   IndexScreen() {
     setStyleName("cookbook-panel");
 
     Panel labelImagePanel = new HorizontalPanel();
     Panel usernamePanel = new VerticalPanel();
-    Image img = new Image(RESOURCES.info());
+    Image img = new Image(CookBookPlugin.RESOURCES.info());
     img.setTitle("User to send greetings to");
     labelImagePanel.add(new Label("Username"));
     labelImagePanel.add(img);
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/PopDownButton.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/PopDownButton.java
new file mode 100644
index 0000000..3cbe5d6
--- /dev/null
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/client/PopDownButton.java
@@ -0,0 +1,101 @@
+// Copyright (C) 2015 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.googlesource.gerrit.plugins.cookbook.client;
+
+import com.google.gwt.dom.client.Document;
+import com.google.gwt.dom.client.Style;
+import com.google.gwt.dom.client.Style.FontWeight;
+import com.google.gwt.dom.client.Style.Unit;
+import com.google.gwt.event.dom.client.ClickEvent;
+import com.google.gwt.event.dom.client.ClickHandler;
+import com.google.gwt.event.logical.shared.CloseEvent;
+import com.google.gwt.event.logical.shared.CloseHandler;
+import com.google.gwt.user.client.Window;
+import com.google.gwt.user.client.ui.Button;
+import com.google.gwt.user.client.ui.PopupPanel;
+import com.google.gwt.user.client.ui.Widget;
+import com.google.gwtexpui.globalkey.client.GlobalKey;
+import com.google.gwtexpui.safehtml.client.SafeHtmlBuilder;
+
+/**
+ * Pop down button for header line in change screen.
+ *
+ * This class implements a button that on click opens a pop down panel with the
+ * provided widget, similar to the "Patch Sets", "Download" or "Included In" pop
+ * down panels on the change screen.
+ *
+ * This class can *only* be used within a panel that extends the header line of
+ * the change screen, but will not work standalone.
+ */
+public class PopDownButton extends Button {
+  private final Widget widget;
+  private PopupPanel popup;
+
+  public PopDownButton(String text, Widget widget) {
+    // Create Button with inner div. This is required to get proper styling
+    // in the context of the change screen.
+    super((new SafeHtmlBuilder()).openDiv().append(text).closeDiv());
+    getElement().removeClassName("gwt-Button");
+    addClickHandler(new ClickHandler() {
+      @Override
+      public void onClick(ClickEvent event) {
+        show();
+      }
+    });
+    this.widget = widget;
+  }
+
+  private void show() {
+    if (popup != null) {
+      getElement().getStyle().clearFontWeight();
+      popup.hide();
+      return;
+    }
+
+    final Widget relativeTo = getParent();
+    final PopupPanel p = new PopupPanel(true) {
+      @Override
+      public void setPopupPosition(int left, int top) {
+        top -= Document.get().getBodyOffsetTop();
+
+        int w = Window.getScrollLeft() + Window.getClientWidth();
+        int r = relativeTo.getAbsoluteLeft() + relativeTo.getOffsetWidth();
+        int right = w - r;
+        Style style = getElement().getStyle();
+        style.clearProperty("left");
+        style.setPropertyPx("right", right);
+        style.setPropertyPx("top", top);
+      }
+    };
+    Style popupStyle = p.getElement().getStyle();
+    popupStyle.setBorderWidth(0, Unit.PX);
+    popupStyle.setBackgroundColor("#EEEEEE");
+    p.addAutoHidePartner(getElement());
+    p.addCloseHandler(new CloseHandler<PopupPanel>() {
+      @Override
+      public void onClose(CloseEvent<PopupPanel> event) {
+        if (popup == p) {
+          getElement().getStyle().clearFontWeight();
+          popup = null;
+        }
+      }
+    });
+    p.add(widget);
+    p.showRelativeTo(relativeTo);
+    GlobalKey.dialog(p);
+    getElement().getStyle().setFontWeight(FontWeight.BOLD);
+    popup = p;
+  }
+}
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/pluginprovider/HelloSshCommand.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/pluginprovider/HelloSshCommand.java
index b1da6de..853d04d 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/cookbook/pluginprovider/HelloSshCommand.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/pluginprovider/HelloSshCommand.java
@@ -14,39 +14,64 @@
 
 package com.googlesource.gerrit.plugins.cookbook.pluginprovider;
 
+import com.google.gerrit.extensions.annotations.PluginData;
 import com.google.gerrit.extensions.annotations.PluginName;
 import com.google.gerrit.server.config.SitePaths;
 import com.google.gerrit.sshd.CommandMetaData;
 import com.google.gerrit.sshd.SshCommand;
 import com.google.inject.Inject;
 
-import java.io.File;
-import java.io.IOException;
-import java.nio.file.Files;
+import org.kohsuke.args4j.Argument;
 
-/**
- * SSH command defined by dynamically registered plugins.
- *
- */
-@CommandMetaData(name = "print", description = "Print content of the plugin file")
+import java.io.IOException;
+import java.io.PrintWriter;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.ArrayList;
+import java.util.List;
+
+/** SSH command defined by dynamically registered plugins. */
+@CommandMetaData(name = "cat", description = "Print content of plugin file")
 public final class HelloSshCommand extends SshCommand {
   private final String pluginName;
-  private final File pluginDir;
+  private final Path pluginDir;
+  private final Path dataDir;
+
+  @Argument(usage = "files in data directory to print")
+  private List<String> files = new ArrayList<>();
 
   @Inject
-  public HelloSshCommand(@PluginName String pluginName, SitePaths sitePaths) {
+  public HelloSshCommand(@PluginName String pluginName,
+      SitePaths sitePaths,
+      @PluginData Path dataDir) {
     this.pluginName = pluginName;
-    this.pluginDir = sitePaths.plugins_dir;
+    this.pluginDir = sitePaths.plugins_dir.normalize();
+    this.dataDir = dataDir.normalize();
   }
 
   @Override
   public void run() {
-    File pluginFile = new File(pluginDir, pluginName + ".ssh");
+    Path pluginPath = pluginDir.resolve(pluginName + ".ssh");
+    printOne(pluginPath);
+    for (String name : files) {
+      Path p = dataDir.resolve(name).normalize();
+      if (!p.startsWith(dataDir)) {
+        throw new RuntimeException(p + " is outside data directory " + dataDir);
+      }
+      printOne(p);
+    }
+  }
+
+  private void printOne(Path p) {
     try {
-      Files.copy(pluginFile.toPath(), out);
+      Files.copy(p, out);
     } catch (IOException e) {
-      throw new RuntimeException("Cannot read plugin content of " + pluginFile,
-          e);
+      try (PrintWriter w = new PrintWriter(err)) {
+        w.write("Error reading contents of ");
+        w.write(p.toAbsolutePath().toString());
+        w.write(": \n");
+        e.printStackTrace(w);
+      }
     }
   }
 }
diff --git a/src/main/java/com/googlesource/gerrit/plugins/cookbook/pluginprovider/HelloSshPluginProvider.java b/src/main/java/com/googlesource/gerrit/plugins/cookbook/pluginprovider/HelloSshPluginProvider.java
index a7d7268..8ffd8c2 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/cookbook/pluginprovider/HelloSshPluginProvider.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/cookbook/pluginprovider/HelloSshPluginProvider.java
@@ -22,19 +22,25 @@
 
 import org.eclipse.jgit.internal.storage.file.FileSnapshot;
 
-import java.io.File;
+import java.nio.file.Path;
 
 /**
- * Dynamic provider of Gerrit plugins derived by *.ssh files under $GERRIT_SITE/plugins.
- *
+ * Dynamic provider of Gerrit plugins derived by *.ssh files under
+ * $GERRIT_SITE/plugins.
+ * <p>
  * Example of how to define a dynamic Gerrit plugin provider to register
  * a new plugin based on the content of *.ssh files.
- *
+ * <p>
  * This provider allows to define a Gerrit plugin by simply dropping a .ssh file
  * (e.g. hello.ssh) under $GERRIT_SITE/plugins.
+ * <p>
  * Once the file is created a new plugin is automatically loaded with the name
- * without extension of the .ssh file (e.g. hello) and a new 'cat' SSH command is
- * automatically available from the registered plugin.
+ * without extension of the .ssh file (e.g. hello) and a new 'cat' SSH command
+ * is automatically available from the registered plugin.
+ * <p>
+ * The 'cat' command will print the contents of the .ssh file, along with the
+ * contents of any arguments, resolved against the plugin's data directory
+ * $GERRIT_SITE/data/name.
  */
 public class HelloSshPluginProvider implements ServerPluginProvider {
   private static final String SSH_EXT = ".ssh";
@@ -46,22 +52,22 @@
   }
 
   @Override
-  public boolean handles(File srcFile) {
-    return srcFile.getName().endsWith(SSH_EXT);
+  public boolean handles(Path srcPath) {
+    return srcPath.getFileName().toString().endsWith(SSH_EXT);
   }
 
   @Override
-  public String getPluginName(File srcFile) {
-    String srcFileName = srcFile.getName();
-    return srcFileName.substring(0, srcFileName.length() - SSH_EXT.length());
+  public String getPluginName(Path srcPath) {
+    String name = srcPath.getFileName().toString();
+    return name.substring(0, name.length() - SSH_EXT.length());
   }
 
   @Override
-  public ServerPlugin get(File srcFile, FileSnapshot snapshot,
+  public ServerPlugin get(Path srcPath, FileSnapshot snapshot,
       PluginDescription pluginDescriptor) throws InvalidPluginException {
-    String name = getPluginName(srcFile);
+    String name = getPluginName(srcPath);
     return new ServerPlugin(name, pluginDescriptor.canonicalUrl,
-        pluginDescriptor.user, srcFile, snapshot,
+        pluginDescriptor.user, srcPath, snapshot,
         new HelloSshPluginContentScanner(name), pluginDescriptor.dataDir,
         getClass().getClassLoader());
   }