How to trigger an event to show a message tray using a keyboard shortcut?

[Marcin Zajączkowski <mszpak wp pl>]

Hello again

Is it possible in Gnome 3.x to execute by keyboard an event which is
triggered when you hit low right corner using a mouse cursor (to show
"message tray" - I try to use mouse as rarely as possible and sometimes
would like to have a look at system monitor charts (displayed in that
bar) or notification icons). I know about super key, but switching to
overview/overlay mode is much more too verbose for my need.

In case that action is not available, maybe there is a simple way to
programmatically trigger an event, to write a simple program/script and
bind it to a custom shortcut?

Regards
Marcin