@Override
	public void scroll(int amount) {
		if (activeHoverService != null) {
			activeHoverService.scroll(amount);
		}
	}
Sets the object that decides where to place the popup window. 
@param popupWindowPlacer the placer
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/hover/AbstractHoverProvider.java