UiCommand: support confirmation message

For some commands, like "Delete-Project", a confirmation dialog must be shown.
Add a support for it in UiCommand. If confirmation message is null or empty
no confirmation dialog is shown. If user cancel confirmation dialog, no
action is triggered.

Change-Id: I2b1e4759b488a3b5079fdb54c6c862ab59397ddf

gerrit-common/src/main/java/com/google/gerrit/common/data/UiCommandDetail.java

@@ -21,4 +21,5 @@ public class UiCommandDetail {
   public String label;
   public String title;
   public boolean enabled;
+  public String confirmationMessage;
 }

gerrit-extension-api/src/main/java/com/google/gerrit/extensions/webui/UiCommand.java

@@ -29,4 +29,5 @@ public interface UiCommand<R extends RestResource> extends RestView<R> {
   String getTitle(R resource);
   boolean isVisible(R resource);
   boolean isEnabled(R resource);
+  String getConfirmationMessage(R resource);
 }

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

@@ -13,6 +13,8 @@
 // limitations under the License.
 
 package com.google.gerrit.client.changes;
+import com.google.gerrit.client.ConfirmationCallback;
+import com.google.gerrit.client.ConfirmationDialog;
 import com.google.gerrit.client.Dispatcher;
 import com.google.gerrit.client.ErrorDialog;
 import com.google.gerrit.client.FormatUtil;
@@ -55,6 +57,7 @@ import com.google.gwt.user.client.ui.Image;
 import com.google.gwt.user.client.ui.HTMLTable.CellFormatter;
 import com.google.gwt.user.client.ui.InlineLabel;
 import com.google.gwt.user.client.ui.Panel;
+import com.google.gwtexpui.safehtml.client.SafeHtmlBuilder;
 import com.google.gwtjsonrpc.common.VoidResult;
 
 import java.util.HashSet;
@@ -555,6 +558,24 @@ class PatchSetComplexDisclosurePanel extends ComplexDisclosurePanel
       b.addClickHandler(new ClickHandler() {
         @Override
         public void onClick(final ClickEvent event) {
+          if (cmd.confirmationMessage != null &&
+              !cmd.confirmationMessage.isEmpty()) {
+            ConfirmationDialog confirmationDialog = new ConfirmationDialog(
+                cmd.title, new SafeHtmlBuilder().append(cmd.confirmationMessage),
+                new ConfirmationCallback() {
+                  @Override
+                  public void onOk() {
+                    postProcessCommand(cmd, b);
+                  }
+                });
+            confirmationDialog.center();
+          } else {
+            postProcessCommand(cmd, b);
+          }
+        }
+
+        private void postProcessCommand(final UiCommandDetail cmd,
+            final Button b) {
           b.setEnabled(false);
           AsyncCallback<NativeString> cb =
               new AsyncCallback<NativeString>() {

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

@@ -111,6 +111,7 @@ public class UiCommands {
             dsc.label = cmd.getLabel(resource);
             dsc.title = cmd.getTitle(resource);
             dsc.enabled = cmd.isEnabled(resource);
+            dsc.confirmationMessage = cmd.getConfirmationMessage(resource);
             return dsc;
           }
         }),