Feature #17677, Please provide a loader as feedback when a user leaves a

VRE

src/main/java/org/gcube/portlets/user/gcubeloggedin/client/ui/AboutView.java

@@ -34,10 +34,11 @@ public class AboutView extends Composite {
 	private static String SEE_MORE = "See more";
 	private Button leaveVreButton = new Button("Leave Group");
 	private AlertBlock alertBlockOnLeave = new AlertBlock();
+	private AlertBlock infoBlock = new AlertBlock();
 	// more options label to show the other ones (if present)
 	final Button showMoreOptions = new Button("Other options ...");
 	private static final String leaveAlertMessage = "Are you sure you want to leave this group? "
-			+ "By leaving this group you will no longer receive updates and lose the workspace folder related to the group.";
+			+ "By leaving this group you will no longer receive updates and lose the workspace folder related to the group. This operation may take a minute or so.";
 
 	// panel for leave group option
 	private VerticalPanel leaveVREOption = new VerticalPanel();
@@ -181,6 +182,12 @@ public class AboutView extends Composite {
 
 			@Override
 			public void onClick(ClickEvent event){
+				infoBlock.setType(AlertType.INFO);
+				infoBlock.setHeading("Operation in progress!");
+				infoBlock.setHTML("please wait ...");
+				leaveVREOption.remove(alertBlockOnLeave);
+				leaveVREOption.add(infoBlock);
+				
 				service.removeUserFromVRE(new AsyncCallback<String>() {
 					@Override
 					public void onSuccess(String result) {