public void onClick(Widget sender) {
   if (sender == updateUserBtn) {
     updateUserDetails(sender);
   } else if (sender == deleteUserBtn) {
     if (usersList.getSelectedObjects().size() > 0) {
       confirmDeleteUsersDialog.center();
     }
   } else if (sender == addUserBtn) {
     addNewUser();
   } else if (sender == deleteRoleAssignmentBtn) {
     if (assignedRolesList.getSelectedObjects().size() > 0) {
       confirmRemoveRoleAssignmentDialog.center();
     }
   } else if (sender == addRoleAssignmentBtn) {
     List<ProxyPentahoUser> selectedUsers = usersList.getSelectedObjects();
     if (selectedUsers.size() == 1) {
       modifyRoleAssignments(selectedUsers.get(0));
     }
   }
 }
  private void handleDeleteSchedules() {
    final SchedulerToolbarController localThis = this;

    final ConfirmDialog confirm =
        new ConfirmDialog(
            Messages.getString("confirmDelete"), // $NON-NLS-1$
            Messages.getString(
                "confirmDeleteQuestion", Integer.toString(getNumSubscribers()))); // $NON-NLS-1$
    confirm.setOnOkHandler(
        new ICallback<MessageDialog>() {
          public void onHandle(MessageDialog d) {
            confirm.hide();
            localThis.deleteSelectedSchedules();
          }
        });
    confirm.center();
  }