[Feature request] Non-exclusive global hotkeys

I don't know what the current status of global hotkey support is. As far as I know, there are a few ideas/implementations floating around such as a GNOME protocol that allows binding via a dbus message of some kind (I attempted to find it again, but I can't).

Basically, I'm looking for a way to have a "non-exclusive" global hotkey. An example use case is push-to-talk, where the key used to activate it can still perform its usual functions. Because it's conveniently located, I tend to use "button 9" on my mouse. This button moves the browser forward a page. I'd like to be able to use it for both push-to-talk and still have it control my web browser, file browser, and whatever else generally responds to it.

The most straightforward way I know of to do this without X right now is to listen to evdev. Of course, this requires that the program has permission to access devices under /dev/input, which in the absence of more granular security models, means either running it as root or adding your user to the input group. The latter workaround would allow any application to listen for inputs whether you want it to or not, which is a security issue that I think Wayland wants to address.

So what I am proposing/requesting (without any actual wording or code — I'm sorry, this is not my area of expertise) is a hotkey protocol that fulfills this use case.

Perhaps a standard compositor API for registering to receive input events, whether specific ones or all events. I don't know how this would be made transparent to the user so that they know what applications are doing this; maybe that requires a whole new "permissions system" (Android springs to mind). But regardless, it would be nice if this were possible.