@Override
	public void setOptions(Options options, String optionName) {

		String hoverName = getName();
		if (optionName.equals(hoverName)) {
			enabled = options.getBoolean(hoverName, true);
			return;
		}

		String widthOptionName = optionName + Options.DELIMITER + "Dialog Width";
		String heightOptionName = optionName + Options.DELIMITER + "Dialog Height";

		if (optionName.equals(widthOptionName) || optionName.equals(heightOptionName)) {
			int dialogWidth = options.getInt(widthOptionName, 600);
			if (dialogWidth <= 0) {
				throw new OptionsVetoException(
					"Reference Code Viewer Dialog Width must be greater than 0");
			}
			int dialogHeight = options.getInt(heightOptionName, 400);
			if (dialogHeight <= 0) {
				throw new OptionsVetoException(
					"Reference Code Viewer Dialog Height must be greater than 0");
			}

			Dimension d = new Dimension(dialogWidth, dialogHeight);
			if (panel != null) {
				panel.setPreferredSize(d);
			}
		}
	}
A hover service to show tool tip text for hovering over a reference.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/hover/AbstractReferenceHover.java