private void userSelectionChanged() {
    List<ProxyPentahoUser> selectedUsers = usersList.getSelectedObjects();
    if (selectedUsers.size() == 1) {
      userDetailsPanel.setUser(selectedUsers.get(0));
      List<ProxyPentahoRole> roleList =
          Arrays.asList(UserAndRoleMgmtService.instance().getRoles(selectedUsers.get(0)));
      assignedRolesList.setObjects(roleList);
    } else {
      userDetailsPanel.setUser(null);
      List<ProxyPentahoRole> emptyRoleList = Collections.emptyList();
      assignedRolesList.setObjects(emptyRoleList);
    }
    userDetailsPanel.setEnabled(selectedUsers.size() == 1);
    updateUserBtn.setEnabled(selectedUsers.size() == 1);

    if (selectedUsers.size() > 0) {
      deleteUserBtn.setEnabled(true);
    } else {
      deleteUserBtn.setEnabled(false);
    }

    if (selectedUsers.size() == 1) {
      addRoleAssignmentBtn.setEnabled(true);
    } else {
      addRoleAssignmentBtn.setEnabled(false);
    }

    userDetailsPanel.getUserNameTextBox().setEnabled(false);
    assignedRoleSelectionChanged();
  }
 public void onPopupClosed(PopupPanel sender, boolean autoClosed) {
   if (roleAssignmentsDialog.getRoleAssignmentsModified()) {
     List<ProxyPentahoRole> roleList =
         Arrays.asList(
             UserAndRoleMgmtService.instance().getRoles(roleAssignmentsDialog.getUser()));
     assignedRolesList.setObjects(roleList);
     assignedRoleSelectionChanged();
   }
 }