Alternative Notification System for Macos || Program or CLI to Display Image/Emblem/Icon at corner of screen (no text or box)

Solution 1:

The premiere notification third party notification system for macOS is Growl:

https://github.com/growl/growl

The project was just recently marked as retired (less than a week ago), but you can still download the code and use it. It is very easy to use Growl to trigger a notification from a shell script.

If you can live with the built-in macOS notifications, you can use a command like this from your shell script:

osascript -e 'display notification "Mode change" with title "Mode change"'

This uses the built-in AppleScript function for displaying a local notification. You can ofcourse change the text to be whatever you want, like "Bindings turned on", and so on.

If you want to write your own application to display the notification, you could start looking at this sample application code from Apple:

https://developer.apple.com/library/archive/samplecode/FunkyOverlayWindow/Introduction/Intro.html

It is basically an overlay window that appears on top of every other window at all times. If you make it small, you could use it to display a color when you want, and let it be fully transparent at other times.