private void addressChanged(Address address) {
		if (changing) {
			return;
		}

		Runnable r = () -> {
			if (address != null || addrField.getText().length() == 0) {
				model.setCurrentFallthrough(address);
			}
			else {
				setStatusText("Invalid Address");
				setOkEnabled(false);
				setApplyEnabled(false);
			}
		};
		SwingUtilities.invokeLater(r);
	}
Dialog to prompt for overriding a fallthrough address on an instruction.
Ghidra/Features/Base/src/main/java/ghidra/app/plugin/core/fallthrough/FallThroughDialog.java