public static boolean canBePreprocessed(MouseEvent e, JScrollBar bar) {
  if (e.getID() == MouseEvent.MOUSE_MOVED || e.getID() == MouseEvent.MOUSE_PRESSED) {
    ScrollBarUI ui = bar.getUI();
    if (ui instanceof BasicScrollBarUI) {
      BasicScrollBarUI bui = (BasicScrollBarUI)ui;
      try {
        Rectangle rect = (Rectangle)ReflectionUtil.getDeclaredMethod(BasicScrollBarUI.class, "getThumbBounds", ArrayUtil.EMPTY_CLASS_ARRAY).invoke(bui);
        Point point = SwingUtilities.convertPoint(e.getComponent(), e.getX(), e.getY(), bar);
        return !rect.contains(point);
      }
      catch (Exception e1) {
        return true;
      }
    }
  }
  return true;
}
 

@Override
protected PropertyChangeListener createPropertyChangeListener() {
	return new BasicScrollBarUI.PropertyChangeHandler() {
		@Override
		public void propertyChange( PropertyChangeEvent e ) {
			super.propertyChange( e );

			switch( e.getPropertyName() ) {
				case FlatClientProperties.SCROLL_BAR_SHOW_BUTTONS:
					scrollbar.revalidate();
					scrollbar.repaint();
					break;

				case "componentOrientation":
					// this is missing in BasicScrollBarUI.Handler.propertyChange()
					InputMap inputMap = (InputMap) UIManager.get( "ScrollBar.ancestorInputMap" );
					if( !scrollbar.getComponentOrientation().isLeftToRight() ) {
						InputMap rtlInputMap = (InputMap) UIManager.get( "ScrollBar.ancestorInputMap.RightToLeft" );
						if( rtlInputMap != null ) {
							rtlInputMap.setParent( inputMap );
							inputMap = rtlInputMap;
						}
					}
					SwingUtilities.replaceUIInputMap( scrollbar, JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT, inputMap );
					break;
			}
		}
	};
}
 

public static BasicScrollBarUI createNormal() {
  return new DarculaScrollBarUI();
}