iPhone - Waiting beetween 2 code line for asynchronous task to be done

I have two lines of code that are executed just before the pop of a view. Those two lines are making some scrolling. Because of those 3 animations, there are many things that the user don't see, or let's say don't see well.

I don't want to use callbacks to deal with this. I just need the app to wait s开发者_运维百科ome 0,5 secs for the view to pop, and 0,5 secs more beetween the two scroll calls to let him see what is happening.

How may I do this easily without stopping the animations ?

I tried (quickly) [NSThread sleepForTimeInterval:0.5]; but it stops everything. Of course.

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You can't wait for an animation to finish from the main UI thread without exiting from the current method after the first line and using a callback for the second line.

If you don't like callbacks, your alternative is to queue your two lines for execution in a background thread.