I also have cages that are directly in front of windows, but I do not work out in the world so I am at home so my birds that have their cages directly in front of windows are usually out of their cages when the sun is shining directly on them. I also have bushes growing outside f these windows which serve to block predators from seeing the birds as well as providing shade for the cages when they are in the sun.
Each situation is different and what works for me may not be feasible for you. Predators are not my main concern as my dogs are penned outside the windows that have cages near or in front of them. I have large birds of prey such as hawks and eagles that live in my area and they can tear through a screen as if it were not even there and are large enough to break windows as well, but they are really not a problem for me as my doges are between 65 and 100 pounds, more than large enough to protect my birds. This may not be the case where you live.
Wild parrot do get direct sunlight but from all of my research they tend to congregate below the top of a trees canopy in the shade during the times that they could get overheated by the sun, so they need to have the shade so that they do not get too hot. If you are at home during these times you may have them out so that they can move out of the sun as needed or you may lower or adjust blinds or other window coverings to provide the amount of shade they need. But you may have an outside job that keeps you away during these times so you would need to be aware of these times and take whatever precautions are required for the birds safety and well being when you can't be there to address this in person. A little forethought and planning in advance can go a long way towards solving these issues before there can be a problem.