concerns over wayland and need for wayland app display to X Server

[David Jackson]

On Sun, Feb 19, 2012 at 6:08 PM, Daniel Stone <daniel at fooishbar.org> wrote:

> Hi,
> There's already a Wayland session that runs on X, and as you asked
> for, an X server that runs rootless on Wayland, with full and proper
> integration with a Wayland session.  Hope this satisfies you.
>
> Cheers,
> Daniel
>
> A wayland session that can display wayland apps to X? That is good, yes.
It is not precisely what I requested but at least the wayland apps somehow
can get the the X server. What you meant it seems is that wayland
applications would communicate with a wayland server, which would display
then to an X server? I assume that the wayland session would display to the
X server as an X client connection to an X server. That would be useful as
I could run the wayland session on one computer and have it displayed to an
X server on another computer. That is a good feature to have. That would
provide a sort of network transparency for wayland.


However, this would also need to coupled with a feature that would allow
the wayland apps to be told at runtime which of many possible wayland
sessions to display to, including the wayland sessions running on the X
server, at runtime.

It also is slightly different than the idea I originally suggested, which
was to allow for a single wayland app to be sent to an X server, such as by
different client side drivers which provide the client side wayland API, to
be loaded at runtime into wayland applications, which allow wayland
applications to be displayed to different targets, one of these drivers
would be a driver with an  xlib client library in the driver as the
backend, which would allow an individual wayland application to display to
an X server, rather than an entire wayland session displayed to an X
server. That would sort of allow individual wayland applications to be
network transparent, rather than an entire wayland session.

However, it may be suitable, If i wanted to display a single wayland
application to another computer, to create a single wayland session to be
displayed to X server, having that sent over an X client connection to an X
server on another computer.


 On 19 February 2012 22:04, David Jackson <djackson452 at gmail.com> wrote:
> > When I initially heard of Wayland, my reaction was of great concern, for
> I
> > was concerned that this could affect my network transparency use and my
> > desire to have multiple desktop sessions on the same computer with a mix
> of
> > local and remote apps displayed to them.
> >
> > If wayland can provide assurance of two critical features, the ability
> to on
> > a runtime, per process basis select via a command line switch to display
> a
> > Wayland native application to a local or remote X server, and the already
> > planned feature to allow X applications to be displayed to Wayland, my
> > concerns will be alleviated and I will have no concern over Wayland. The
> > first feature of wayland app to X protocol may be able to be implemented
> by
> > some glue code from wayland client API to xlib to send graphical data
> from
> > the wayland native application onto an X server over X protocol.
> >
> > This feature is vitally important to me.
> >
> > Wayland should take it upon itself to gaurantee that this is possible and
> > provide a standard mechanism to make it possible, perhaps a set of
> Wayland
> > client side drivers can be made which would then send the graphics to a
> > regular X server, and the driver could be selected at runtime on a per
> > process basis. We should not count on widget or application developers to
> > have to explicitely implement this feature but should be gauranteed by
> > wayland itself, the reason is there are some shoddy developers who may
> not
> > expicitely include such a feature, but it is important to make sure that
> all
> > applications can be run on one computer and displayed to another,
> displayed
> > to an X server, or that an application can be displayed to one of many
> local
> > display server sessions, including local X servers such as Xvnc.  This
> > should not be a problem as the driver for either display to X or display
> to
> > wayland target could be linked at runtime perhaps (dynamic link).
> >
> > With the likelyhood that there could be many wayland apps which are
> native
> > eventually and to avoid having to have two copies of each application
> > installed, the above is a sensible and reasonable idea that would
> actually
> > greatly assure the flexibility of wayland since dynamic linking or some
> > other type of runtime client output driver loading would assure that the
> > wayland system is flexible and that other kinds of output drivers could
> also
> > be developed and added to a system without having to recompile any
> > applications. This gives the system flexibility and modularity that can
> give
> > it much more power.
> >
> > We have many computers which are legacy and have only X servers and it
> would
> > be greatly beneficial that there will be a guarantee that future Native
> > wayland apps can be displayed to it on a per app basis, such as through
> this
> > idea that there could be a client side wayland driver that will send the
> > graphics onto an X server over X protocol and that this driver can be
> > selected at run time with a simple command line argument.
> >
> > The driver would probably be glue code between the wayland client API and
> > the xlib API. This would allow a feature that would be critical to us to
> > allow a single wayland app to be displayed to a X server, this would also
> > give us network transparency as well as full backwards and forwards
> > compatibility.
> >
> > The fact we have a network transparent desktop environment where apps are
> > not tied to a single display and one can run multiple instance of an app
> on
> > the same computer displaying to multiple display servers running on local
> > machine and on remote machines has been one of the great strengths of
> Linux.
> > The ability as well to create many headless X sessions which can then be
> > accessed as needed by VNC clients (Xvnc. Xnest, Xvfb+x11vnc) is also of
> > great value.
> >
> > The ability to display a native wayland app to an X server would
> basically
> > assure these possibilities are available and that I will be able to
> continue
> > to route my applications as needed to remote displays on other machines,
> > would assure backward and forward compatibility, and give us full network
> > transparency on the per application level, and allow for multiple local X
> > desktop sessions to be able to remain a possibility whilst using native
> > wayland applications displaying to the X servers.
> >
> >
> >
> > _______________________________________________
> > wayland-devel mailing list
> > wayland-devel at lists.freedesktop.org
> > http://lists.freedesktop.org/mailman/listinfo/wayland-devel
> >
>
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