IOS – Unable to use auto layout (ctrl + drag) on xcode after some time of using

iosmacmacosxcode

I am having a problem with Xcode. It works correctly but sometimes after a period of using it, when I ctrl + drag an element on Interface Builder autoLayout popup shows and disappears immediately. Also, when I want to set constraints manually, I can't do that, because every single click is recognized as a double click as shown in the gifs below.

I tried to find the cause of this, but I can't. To solve it I have to restart /logout every time which is annoying. I observed that in most cases this starts when I connect external monitor to my MBP and use Xcode on that screen.
Can't set value, because xcode recognize simple click as double click

Can't ctrl + drag because contraint popup instanetely dissappears

Best Answer

Another person, had this same problem where performance plummeted on an external display.

What I ended up discovering was that the external monitor issue was indicating that there was a UIView that interface builder couldn't quite figure out properly for auto-layout.

In his case it was a UIToolbarBarItem that contained a UIView that contained a UILabel. Once I removed the offending UIToolbarBarItem the performance issue resolved itself. It went from being completely unusable to smooth scrolling.

You should check if you have a UIView inside something that might cause auto-layout to perform poorly.