Soon I will have to work with OS X and tools like hammerspoon are missing some important capabilities for me. I need to be able to intercept keyboard and mouse events completely from the focused application. Say I ctrl+alt+apple+left_click on an application, I don't want the application to know about that left click. So far the only thing I came up with was to build a transparent fullscreen application, though I'm not sure how feasible that is yet.
Any better idea or hints how to go about this in a language of your choice?
Thanks!
You will need to create an event tap. However, the application will have to run as the root user, or the user will have to authorize that the application has been granted rights to accessibility features.
Apple's documentation can be found here.
Interestingly enough, I am in the process of writing a blog post about how to use event taps (including an ObjectiveC API that I wrote for my own use), but the post won't be made available for another week or so.