shortcuts window: double-click to execute action

[axd1967]

Is your feature request related to a problem? Please describe.
Sometimes I want to see / test what the result is of a specific action, without having to define a shortcut. The shortcuts window (F7) has a nice feature to filter for e.g. "month", which then gives all month actions:

Describe the solution you'd like
When I double-click on a shortcut, I would like that action to trigger. E.g. when click on "subtract one draconic month", Stellarium executes it.

This could be a controversial issue, because it is not the task of the shortcut window to do this kind of things. But I see no immediate use for a double-click in this dialog, although plenty of counter arguments could be given (e.g. reset the action to default).

Describe alternatives you've considered
Assign a shortcut, press it, reassign the shortcut to a different key, press it, etc.

Additional context
Note that the arrangement of a dialog having actionable entries is a very nice alternative to execute actions.

A similar approach works in HiPS:
(note that the user needs to check rather than double-click, but this could easily be added; in fact, there is currently a small ergonomy issue in this behaviour as the user is forced to click inside the checkbox)

in Oculars:

In sats:

[alex-w]

Double-click in shortcut dialog is enable editor of shortcut

[axd1967]

Double-click in shortcut dialog is enable editor of shortcut

Dang - you mean this

stellarium/src/gui/ShortcutsDialog.cpp

Lines 307 to 308 in ac0bfee

	connect(ui->shortcutsTreeView, SIGNAL(activated(QModelIndex)),
	this, SLOT(switchToEditors(QModelIndex)));

Back to the drawing board.

[alex-w]

Yes, you mark correct LOC