@Override
	public int getScrollableUnitIncrement(int topOfScreen, int direction, int max) {
		if ((topOfScreen < -heightAbove) || (topOfScreen > heightBelow)) {
			return max;
		}

		if (direction > 0) { // if scrolling down
			return heightBelow - topOfScreen;
		}
		return -heightAbove - topOfScreen;
	}
@see docking.widgets.fieldpanel.field.Field#getScrollableUnitIncrement(int, int, int)
Ghidra/Framework/Docking/src/main/java/docking/widgets/fieldpanel/field/SimpleTextField.java