int (int direction) { JViewport viewport = getViewport(); if (viewport != null) { Scrollable scrollable = getScrollableViewToCalculateIncrement(viewport.getView()); if (scrollable != null) return scrollable.getScrollableUnitIncrement(viewport.getViewRect(), orientation, direction); if (!isUnitIncrementSet) { Font font = getViewFont(viewport); if (font != null) return font.getSize(); // increase default unit increment for fast scrolling } } return super.getUnitIncrement(direction); }