What happens to the timer if the user closes the application's window (causing the app to become inactive) but does not fully quit it? Does the timer continue to run, pause, or behave in some other way?
Will the app nap feature stop the timer when app is in-active state?
From the general "flavor" of your questions, I suspect you're coming from iOS and relatively new to macOS development. That matters because there is a "mindset" difference between macOS and iOS which completely changes all of those questions. On iOS, the system fundamentally constrains how apps operate, fully controlling exactly how and when code executes.
macOS simply does not work that way and simply does not implement the kinds of constraints iOS does. For example, the answer here:
Will the app nap feature stop the timer when app is in-active state?
...is that app nap probably does stop the timer but that doesn't really matter, as the app can simply choose not to nap. More broadly, the answer to basically "all" of those questions is "what actually ends up happening is whatever your app chooses to do". I'm sure there is some default behavior, but that doesn't really matter because the system has given your app enough control that it can ultimately do whatever it chooses.
Some of our frameworks (particularly SwiftUI and to a lesser extent Catalyst) do reimplement some of the behavior's iOS imposes but those behavior are part of the framework's implementation, not inherent to the system itself. However, those behavior can always be modified/bypassed by either tweaking the apps implementation or, at worst, bypassing the framework entirely.
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Kevin Elliott
DTS Engineer, CoreOS/Hardware
