Re: How to keep UNO applications connected after closing LibreOffice

On 09/16/2016 03:39 PM, Samuel Mehrbrodt wrote:
> We have the following case:
> You have an application conntected to LO via UNO. The user then
> separately starts a (Start center) window. When he closes it, LO gets
> terminated and the external application loses the connection. We want to
> prevent thatso that the external application keeps working.

The usual pragmatic solution is to use an explicit UserInstallation for 
the external application.

> We could use a TerminationVetoException
> <https://www.openoffice.org/api/docs/common/ref/com/sun/star/frame/TerminationVetoException.html>
> in the external application to prevent LO from terminating. But this has
> the side effect that the user can no longer close the Start center.
>
> Basically we have two options how to fix this:
>
>  1. Change the behavior of LO such that the TerminationVetoException
>     allows closing the last window, but still prevents terminating the
>     soffice process

At least for desktop environments that do not clearly indicate that an 
app is still running when its last window is closed, one downside of 
this could be that users might not be aware of LO still running when 
they intended to close it.

>  2. Change the behavior of LO such that an open UNO connection counts as
>     an open window, and the process doesn't get terminated until all
>     connections are closed.
>     This option would not need a TerminationVetoException.
>
> Both options do change existing behavior and will possible break
> existing applications/workflows out there. So the decision should be
> made carefully.
>
> I probably would go for the first one, since the
> TerminationVetoException suggests that it will prevent termination. It
> shouldn't affect closing a window.
> Although I would also consider it as a bug that LO terminates (when
> closing a window) while it still has active connections.
>
> Any input on this?

I think I'd be fine with improvements in either direction.