Poor idle detection, proposes untimely mini-breaks

[Chealer]

I decided to give Stretchly a second chance with version 1.17.2 and have managed to substitute it for Workrave for a week, thanks to big improvements. One of the worst issues left is break scheduling. The number of breaks Stretchly proposes at untimely moments is high. A memorable case was when I came back from the washroom after washing my teeth and noticed Stretchly about to start a mini-break (even though my mini-breaks only last 50 s). There have also been several times when I heard the PC and went to it to see what was going on only to notice Stretchly proposing a break.

Stretchly's break scheduling model appears to be poorly documented, but the README does contain:

Stretchly is monitoring your idle time, so when you are idle for 5 minutes, breaks will be paused until you return.

This probably means that the user is considered active for 5 minutes after its last input, which would explain the behavior. Besides the annoying sounds and wasted resources, this mostly means users have to skip breaks proposed at untimely moments, which I don't think Stretchly really allows.

This occurs under Microsoft Windows 11.

Distinguishing activity from idleness is far from trivial, so perfection is certainly not possible, but the frequency of untimely breaks could be largely reduced by:

1. only proposing breaks when the user is positively active
2. not proposing breaks when proximity sensors do not detect any user and no input device is being used, and/or
3. modifying the constant used by the heuristic described above (either reducing the timer or at least making it configurable).

(Note that Stretchly triggered a mini-break during a ½-hour break I took while reporting this.🙄)