On recent versions of macOS, when a window is being shared (via the system screen-capture APIs), the OS sometimes shows a small "shared window" badge in the title bar.
I’ve noticed that this indicator is not consistent:
For some windows, the badge reliably appears when they are being shared.
For other windows, the badge never appears, even though the window is actively shared.
In particular, windows that use a standard system title bar seem to show the indicator more often, while windows with custom-drawn or non-standard chrome do not.
My questions are:
What are the exact conditions under which macOS decides to draw the “shared window” indicator in a window’s title bar?
Is this strictly tied to certain NSWindow styles or masks (e.g. titled vs borderless)?
Is there any API or flag I can use to detect programmatically whether a given window will display this system indicator when shared?
Topic:
Accessibility & Inclusion
SubTopic:
General