Click shortcut for menu bar icon

[x-magic]

Currently the menu bar icon brings up a menu whether it's clicked by left or right mouse button.

What if one of the mouse button will still bring up the menu, but the other button would instead start/stop "casting"?

Example: Scroll reverser app - when menu icon is clicked by right mouse button, it toggles the status of main function, while clicked by left mouse button would bring up the menu instead.