public final boolean isAlphaModeEnabled(final Window window) {
   if (!window.isDisplayable() || !window.isShowing()) {
     throw new IllegalArgumentException(
         "window must be displayable and showing. window=" + window);
   }
   return isAlphaModeSupported();
 }
 private static void repaintUI(Window window) {
   if (!window.isDisplayable()) {
     return;
   }
   window.repaint();
   Window[] children = window.getOwnedWindows();
   for (Window aChildren : children) {
     repaintUI(aChildren);
   }
 }
 private static void updateUI(Window window) {
   if (!window.isDisplayable()) {
     return;
   }
   IJSwingUtilities.updateComponentTreeUI(window);
   Window[] children = window.getOwnedWindows();
   for (Window aChildren : children) {
     updateUI(aChildren);
   }
 }
  public final void setAlphaModeRatio(final Window window, final float ratio) {
    if (!window.isDisplayable() || !window.isShowing()) {
      throw new IllegalArgumentException(
          "window must be displayable and showing. window=" + window);
    }
    if (ratio < 0.0f || ratio > 1.0f) {
      throw new IllegalArgumentException("ratio must be in [0..1] range. ratio=" + ratio);
    }
    if (!isAlphaModeSupported() || !isAlphaModeEnabled(window)) {
      return;
    }

    setAlphaMode(window, ratio);
  }
 public final void setAlphaModeEnabled(final Window window, final boolean state) {
   if (!window.isDisplayable() || !window.isShowing()) {
     throw new IllegalArgumentException(
         "window must be displayable and showing. window=" + window);
   }
 }