@Override
  protected void evaluate() {
    if (!isNotEvaluated) return;

    final Expression expLabel = styleElement.getLabel();

    // we can not know so always visible
    isStaticVisible = VisibilityState.VISIBLE;

    if (GO2Utilities.isStatic(expLabel)) {
      label = GO2Utilities.evaluate(expLabel, null, String.class, "No Label");
    } else {
      GO2Utilities.getRequieredAttributsName(expLabel, requieredAttributs);
      isStatic = false;
    }

    cachedFont.getRequieredAttributsName(requieredAttributs);
    cachedFill.getRequieredAttributsName(requieredAttributs);
    cachedHalo.getRequieredAttributsName(requieredAttributs);
    cachedPlacement.getRequieredAttributsName(requieredAttributs);

    // no attributs needed replace with static empty list.
    if (requieredAttributs.isEmpty()) {
      requieredAttributs = EMPTY_ATTRIBUTS;
    }

    isNotEvaluated = false;
  }
  public CachedTextSymbolizer(
      final TextSymbolizer symbolizer,
      final SymbolizerRendererService<TextSymbolizer, ? extends CachedSymbolizer<TextSymbolizer>>
          renderer) {
    super(symbolizer, renderer);

    final org.opengis.style.Font font = styleElement.getFont();
    cachedFont = CachedFont.cache(font);

    final Fill fill = styleElement.getFill();
    cachedFill = CachedFill.cache(fill);

    // halo can be null.
    final Halo halo = styleElement.getHalo();
    if (halo != null) {
      cachedHalo = CachedHalo.cache(halo);
    } else {
      cachedHalo = null;
    }

    final LabelPlacement placement = styleElement.getLabelPlacement();
    if (placement instanceof PointPlacement) {
      cachedPlacement = CachedPointPlacement.cache((PointPlacement) placement);
    } else if (placement instanceof LinePlacement) {
      cachedPlacement = CachedLinePlacement.cache((LinePlacement) placement);
    } else {
      throw new IllegalArgumentException(
          "A text symbolizer must have a placement set of type : PointPlacement or LinePlacement.");
    }

    styleElement.getFont();
    //        symbol.getGeometryPropertyName();
    styleElement.getHalo();
    styleElement.getLabel();
    styleElement.getLabelPlacement();
    styleElement.getUnitOfMeasure();
  }
 public Font getJ2dFont(final Object candidate, final float coeff) {
   return cachedFont.getJ2dFont(candidate, coeff);
 }