Long press global shortcuts

[Aleix Pol]

Hi,
In a discussion some weeks ago, we came to the conclusion that it
would make sense to support long press global shortcuts.

The use-case we discussed back then was the power button on the Plasma
phone. We need to have 2 actions upon press. Short press would lock
and dim the screen, long press would show the shutdown button.
Thinking about it further makes me think it's something we probably
want for the desktop use-case as well.

The problem is two-fold:
- We need to support long-press on kglobal accel (or even QShortcut?)
- When do we trigger the action? Because now it happens on pressed.

The second part of this is why I'm sending this e-mail. We're
responding to global shortcuts on press rather than on release, which
makes it impossible to handle the long press. Would it make sense to
change it to on release? Maybe only in the cases where there's a long
press counterpart?

Aleix