The fact that iOS plays nicely with apps that ask to prevent screenshotting is a foundational bug. Does such an ability exist on stock Android? Either way, it’s best practice to root & jailbreak.
[1] https://developer.android.com/reference/android/view/WindowM... [2] https://stackoverflow.com/a/30618030
In fact, iOS does not provide any tools to prevent screenshotting, on the contrary, this feature requires some nasty hacks to pull off.
One of them is actually even patented and it requires rendering whatever you want to protect (text, image, etc) into a one frame DRM protected video and rendering that instead.
Any screenshot would only get one frame. You may have to stitch together multiple frames to get any useful data.
I wonder if this would work.
When I used feature "screen cast" and tried to cast Firefoxs private tab, I just got black screen.
for example private Firefox tabs do not show a preview in the system activity preview, it is a general "do not let the content of the screen escape the control of this app"