Re: vnc clipboard support

[Marc-André Lureau]

Hi

On Tue, Feb 2, 2021 at 9:18 PM Gerd Hoffmann <kraxel@redhat.com> wrote:
>
> On Tue, Feb 02, 2021 at 02:35:34PM +0100, Gerd Hoffmann wrote:
> >   Hi,
> >
> > > The VNC protocol is way too crude. It is limited to transferring
> > > plain text, and provides no way to specify or negotiate a character
> > > set. The RFB spec says apps should use latin-1. In reality few, if any,
> > > impls do charset conversion so most Linux impls will be sending UTF8
> > > while Windows impls will be sending Windows Codepage 1252. It clearly
> > > shows its heritage of being designed in the 1990s.
> >
> > Well, there is an extension which supports more than just text.  But it
> > is a small number of formats which clearly has window-ish background,
> > for example rich text format (windows wordpad) for formated text and dib
> > (aka windows device independant bitmap) for images.
>
> Well, spice isn't that much better.  Has a short, fixed list too:
>
> VD_AGENT_CLIPBOARD_UTF8_TEXT
> VD_AGENT_CLIPBOARD_IMAGE_PNG (mandatory if images supported)
> VD_AGENT_CLIPBOARD_IMAGE_{BMP,TIFF,JPEG} (optional)
>
> There also is ...
>
> VD_AGENT_CLIPBOARD_FILE_LIST
>
> ... but that works hand-in-hand with the spice webdav server.
>

There has been some attempts to support generic mime types in Spice clipboard:
https://lists.freedesktop.org/archives/spice-devel/2018-May/043782.html

(If I am not mistaken, I think it was inspired on some earlier attempt
I worked on I lost trace)

In any case, it seems there is just not enough interest for other
things beside the existing Spice clipboard types. Interoperability
between OSes quickly becomes problematic for more advanced types, I am
afraid. (and various OS-specific clipboard & dnd details may raise)

-- 
Marc-André Lureau