[X2Go-User] Configure x2go-client to not forward specific key combinations?

[Jonah Benton]

Thank you- hmm, it looks like using the autograb key combo (c-a-g) causes
the entire window to disappear. In the session.log below, this shows up as
a request to suspend the session. Is that expected behavior? I'm using the
Fedora 32 XFCE spin, with Fedora's packaging of x2go, for both local and
remote environments.

Info: using keystrokes file '/etc/x2go/keystrokes.cfg'
Info: ignoring unknown keystroke action 'debug_tree'.
Info: ignoring unknown keystroke action 'regions_on_screen'.
Info: ignoring unknown keystroke action 'test_input'.
Info: ignoring unknown keystroke action 'deactivate_input_devices_grab'.
Currently known keystrokes:
  close_session         : Ctrl+Alt+t
  switch_all_screens    : Ctrl+Alt+f
  minimize              : Ctrl+Alt+m
  resize                : Ctrl+Alt+r
  defer                 : Ctrl+Alt+e
  ignore                : Ctrl+Alt+BackSpace
  force_synchronization : Ctrl+Alt+j
  fullscreen            : Ctrl+Shift+Alt+f
  autograb              : Ctrl+Alt+g
  viewport_move_left    : Ctrl+Shift+Alt+Left
  viewport_move_right   : Ctrl+Alt+Right
Session: Session resumed at 'Fri Jul 10 10:32:35 2020'.
Info: Screen [0] resized to geometry [2560x1576] fullscreen [0].
cat: /proc/183021/environ: Permission denied
Session: Suspending session at 'Fri Jul 10 10:32:54 2020'.
Info: Waiting the cleanup timeout to complete.
Session: Session suspended at 'Fri Jul 10 10:32:55 2020'.



On Fri, Jul 10, 2020 at 8:52 AM Ulrich Sibiller <uli42 at gmx.de> wrote:

>
>
> On Fri, Jul 10, 2020 at 2:41 PM Jonah Benton <jonah at jonah.com> wrote:
> >
> > Thank you Uli, follow up below-
> >
> > On Fri, Jul 10, 2020, 2:52 AM Ulrich Sibiller <uli42 at gmx.de> wrote:
> >>
> >> On Thu, Jul 9, 2020 at 10:54 PM Jonah Benton <jonah at jonah.com> wrote:
> >> >
> >> > Hi folks,
> >> >
> >> > I'm interested in using x2go to:
> >> >
> >> > * connect into several individual accounts/machines at the same time
> >> > * use each remote machine desktop in full screen mode
> >> > * switch between remote full screen desktops using a specific key
> combination, which would therefore not be sent to the remote
> >> >
> >> > Is this possible?
> >> >
> >> > In my initial perusal of man pages and testing I don't see a way to
> do what seems to me to be the (probably wrong) solution- instruct the
> x2go-client (in either launch remote desktop mode, or desktop screen
> sharing mode) to not capture a specific key combination (like
> control-alt-right arrow and control-alt-left arrow) so that the parent
> desktop can handle them (e.g. switch between parent-side virtual desktops).
> >>
> >> Well, switching between application windows is a task of your local
> >> window manager or, more precisely, its task switching app. The reason
> >> you cannot do this in fullscreen sessions is that a session running in
> >> fullscreen mode will grab the X server to get ALL keys. That means no
> >> other application will get notified of keypresses. The hotkeys
> >> ("keystrokes") will be processed by the nxagent and will not reach the
> >> session. All others will be forwarded to the session. We could add
> >> another keystroke, something like "passthrough" or similar to pass
> >> that keystroke to your local X server. But even then I doubt that
> >> would work at all because usually grabbing prevents such things from
> >> happening. The only other options was to explicitly disable the grab
> >> in fullscreen mode which will probably lead to making your local
> >> session unusable because a window that is covered by the x2go
> >> fullscreen needs some interaction but cannot be activated or similar.
> >>
> >> A more pragmatic approach: do not run in fullscreen but use maximized
> >> windows instead. Then your local window manager/task switcher will
> >> happily fullfill your request to switch to another x2go session.
> >>
> >> Uli
> >
> >
> >
> > The explanation is very helpful and it along with running some
> experiments has clarified the mental model and convinced me of the futility
> of my imagined approach. Events are pushed to the client window without
> grab, but are pulled by the window with grab, acted on or not, and
> discarded.
> >
> > So re using maximized windows- the grab behavior allows for key
> combinations like alt-tab, or copy paste, that are present both locally and
> remotely to be only processed remotely.
> >
> > In the absence of grab, can I still achieve the ergonomics of working
> natively in the remote environment, as with alt-tab? For keys, would I need
> to bind each needed key combination in the remote environment to a key
> combination unused in the local environment? Or maybe only alt-tab and
> shift-alt-tab?
> >
> > Or is there an "ungrab" but leave full screen, then "regrab" when
> necessary?
>
> Hmm, some time I ago we implemented a feature called "autograb". In
> default setup you can can enable/disable it using ctrl-alt-g. In that mode
> the grab gets activated when the x2go window gets focus. That means when
> the window is active alt-tab and other combinations will be grabbed by x2go
> while they will be interpreted by the local session when the x2go window is
> not active. This allows you to use alt-tab in an x2go session without the
> local session interfering. So I suggest you experiment with a mixture of
> alt-tab and ctrl-alt-g. If you see room for improvement here please let us
> know.
>
> Uli
>
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