Catalonian Separatist Movement

Hello! I got back from a trip to Spain a couple of weeks ago and, as my trip came to a close in Barcelona, I began wondering: how is the Catalonian separatist movement viewed by the rest of Spain? Are most people outside of government apathetic about it, irritated by it, supportive of it? While I was in Barcelona I saw endless Catalonian flags hanging from terraces, was told by a tour guide that Spanish prime ministers aren't especially welcome in the city and, looking at a map of the most recent election for Spanish prime minister, saw that Catalonia and a couple of surrounding areas voted for a separatist candidate rather than other, more national candidates. I apologize if there's any nuances that I'm not picking up on. I have a rough understanding of the history of the Catalonia but, being from California, I'm mostly uneducated on the issue. Thanks!