add support for blocking screenshots being taken

[grrrrr]

I am aware that this is not a perfect privacy solution and there are ways around it but it would be useful to have etar block the ability to take screenshots.

While the risks / concerns of someone remotely taking a screenshot of etar on most peoples devices phone are low there are still users who are high risk, it is a possibility that some malware is setup to take screenshots of open apps. Given the nature of calendars this could include sensitive information

Additionally with screenshots blocked, switching apps would result in you seeing etar is your list of open apps but not seeing the screen it's contents

My suggestion would be to add a toggle option to settings -> general settings that would allow people to turn on or off the blocking of screenshots.

Some apps that do that have this option if examples/comparison is needed

• Signal (allows toggling screenshot capture on or off)
• Protonmail (always blocked)
• Aegis (allows toggling screenshot capture on or off)
• KeepassDX (always blocked)

[binayshaw7777]

I would like to work on this Issue.

[Gitsaibot]

Feel free come up with a PR ;)

[grrrrr]

@binayshaw7777 if it's any use, a recent example in another app https://github.com/QuantumBadger/RedReader/pull/955