Yahoo finance says they're doing well. If this is a sign of decline then most companies would be happy getting such results.
Current revenue doesn't necessarily say anything about future decline, you need to look deeper than that.
If anything, Apple's fat profits are a danger sign. That kind of money attracts people who like spending lots of money. It removes any need for discipline. It discourages innovation, because people are afraid to do anything that might disturb the giant cash pipeline.