@Override
	public int getScrollableUnitIncrement(int topOfScreen, int direction, int max) {
		if ((topOfScreen < startY) || (topOfScreen > startY + height)) {
			return max;
		}

		if (direction > 0) { // if scrolling down
			return height - (topOfScreen - startY);
		}
		return startY - topOfScreen;
	}
Sets the starting vertical position of this field.
@param startY the starting vertical position.
Ghidra/Features/Base/src/main/java/ghidra/app/util/viewer/field/IndentField.java