Many thanks for all the responses. In terms of what I'm doing, the NSTimer with 0.1 second granularity sounds like the best fit.
> On 28 Jul 2017, at 7:26 pm, Charles Srstka <cocoa...@charlessoft.com> wrote: > > If you’re using Swift <snip> Still on Objective-C. Thanks though, I'll keep that bookmarked for when I venture into Swift! > On 28 Jul 2017, at 6:57 pm, Quincey Morris > <quinceymor...@rivergatesoftware.com> wrote: > > On Jul 28, 2017, at 08:57 , Mark Allan <markjal...@gmail.com > <mailto:markjal...@gmail.com>> wrote: >> >> I have an app with a helper tool that performs some lengthy process in a >> loop and reports progress to the user. It works out how many iterations of >> the loop will be needed, sets the progressbar.maxValue, and then increments >> the progress bar's value on each iteration. > > Can you clarify this description? Is the helper tool running in a separate > process, in which case how (and how often) is it reporting progress back to > the app? Is it the helper tool that’s looping progressbar.maxValue times? > What is the app doing while the helper tool is running? > > Also, it seems like a “code smell” if the code that’s iterating millions of > times is updating a progress bar directly. Actually, two issues: > > 1. In a MVC design, code that’s calculating like this is generally part of > the model, and shouldn’t be aware of what UI element is reporting progress, > even though the model may provide some progress information. > > 2. The iteration is presumably on a background thread, and it’s not clear how > you transfer the progress information safely to the main thread. > > The normal solution to #1 is some kind of observation (of the progress > information), and to #2 is some kind of trampoline. Both of those techniques > lend themselves to thinning the frequency of UI updates, so you have choices > about how to do that. > > I’m agnostic on timer vs. elapsed-time update thinning. Both are easy enough > to do, once you figure out *where* to do them. Apologies for the lack of detail/clarity - I simplified things for the sake of keeping the email short. The loop most definitely is not updating the progress bar directly. In fact, the helper tool is a separate process, communicating via NSXPCConnection, so it couldn't update it directly even if I wanted it to! Reducing the frequency of NSXPC messages was a secondary goal to figuring out how often the main app ought to be updating the UI. Mark _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
