[Interest] Press and hold keyboard key to bring up menu in QML

[Reinhardt Behm]

On Friday 01 April 2016 14:33:29 Elvis Stansvik wrote:
> 2016-04-01 12:45 GMT+02:00 Elvis Stansvik <elvstone at gmail.com>:
> > Hi folks,
> > 
> > I have a full screen, page based Qt Quick 2 application. Input is
> > contstrained by the hardware to the Left/Right/Return keyboard keys,
> > so is quite limited, and navigation between pages is done using
> > buttons on each page which handle return presses using (most of the
> > time) Keys.onReturnPressed and navigation between buttons and other
> > items with KeyNavigation.left/right.
> > 
> > I now have the need to provide a special global shortcut: On almost
> > all of the screens, holding the Enter key for 3 seconds should bring
> > the user immediately to a sort of start screen, where he/she can
> > choose to go into Settings or Power Off. Kind of like how holding the
> > power button on a phone often brings up a power off/flight mode menu.
> > 
> > I'm struggling to find a good way to handle this centrally: since
> > Enter presses are normally accepted (swallowed) by my various buttons
> > and other input items on the pages, where can I put some central key
> > press/release handler in which to start/stop a timer (to determine if
> > it was a long 3 sec press or not)?
> > 
> > My pages are FocusScopes stuffed in a StackView inside a Window.
> > 
> > Many thanks for any advice. Has noone had this kind of requirement
> > before? (Global "hold key" shortcut).
> 
> Actually, scratch this. Our input device is a pushable wheel, and I've
> realized now that we better re-program the Arduino we have hooked up
> to it to have the logic to determine "long" vs "short" presses there
> instead, and deliver these as distinct keypresses.
> 

Well this might be the better idea.
I don't know enough about Qt Quick since I am doing everything in C++ and 
widgets. But there I would install an event filter on every page, catching 
keypress/release for the enter key, but no eating it up. Start a QTimer on 
press, stop it on release. If it fires, enter was pressed long and this can 
trigger your global action.

Reinhardt