Whow... whoop-de-doo. So they did... and lost.
"Judge Vaughn R. Walker of the Federal District Court in San Francisco threw out five of the six counts in Xerox's lawsuit (against Apple) . . . . The one count the judge did not throw out was Xerox 's request for a declaration that it is the sole owner of the Star technology. But he said that to bring suit on that count, Xerox would have to show it had a reasonable fear that Apple would try to take away Xerox's copyrights. He gave Xerox 30 days to come up with the evidence and a list of witnesses."
They didn't... and that count was dismissed as unpursued.
Incidentally, at the time of the lawsuit, the Star (Dandylion or D'lion) was already in the morgue of dead computers, having been introduced in 1981 as a "workstation" on a office network and selling a little over 25,000 units.
Just as Apple lost when they tried to sue Microsoft. This just proves your MacPropaganda piece is - say it with me - MacPropaganda and has little connection with reality. Xerox was pissed at Apple and Apple did not license the GUI.