message: grey out showServiceNodes option when graphType=service
diff: @@ -10,6 +10,8 @@ import { ListPagesHelper } from '../../components/ListPage/ListPagesHelper';
  import { GraphFilterState, KialiAppState } from '../../store/Store';
  import { KialiAppAction } from '../../actions/KialiAppAction';
  import { GraphFilterActions } from '../../actions/GraphFilterActions';
  +import { GraphType } from '../../types/Graph';
  +import { PfColors } from '../Pf/PfColors';
  type ReduxProps = Omit<GraphFilterState, 'showLegend'> & {
  // Dispatch methods
  @@ -27,6 +29,7 @@ type GraphSettingsProps = ReduxProps;
  interface VisibilityLayersType {
  id: string;
  + disabled?: boolean;
  labelText: string;
  value: boolean;
  onChange: () => void;
  @@ -90,6 +93,7 @@ class GraphSettings extends React.PureComponent<GraphSettingsProps> {
  },
  {
  id: 'filterServiceNodes',
  + disabled: this.props.graphType === GraphType.SERVICE,
  labelText: 'Service Nodes',
  value: showServiceNodes,
  onChange: toggleServiceNodes
  @@ -136,12 +140,13 @@ class GraphSettings extends React.PureComponent<GraphSettingsProps> {
  ];
  const checkboxStyle = style({ marginLeft: 5 });
  + const disabledCheckboxStyle = style({ marginLeft: 5, color: PfColors.Gray });
  const displaySettingItems = visibilityLayers.map((item: VisibilityLayersType) => (
  <div id={item.id} key={item.id}>
  <label>
  - <input type="checkbox" checked={item.value} onChange={() => item.onChange()} />
  - <span className={checkboxStyle}>{item.labelText}</span>
  + <input type="checkbox" checked={item.value} onChange={() => item.onChange()} disabled={item.disabled} />
  + <span className={item.disabled ? disabledCheckboxStyle : checkboxStyle}>{item.labelText}</span>
  </label>
  </div>
  ));
  