Re: Pixmap Problem

[Pablo Mejia <pjm cctechnol com>]

>>>>> "Jiang" == Jiang XU <jiang.xu@echostar.com> writes:

    Jiang> Actually, what I am trying to do is let the different
    Jiang> process (running at the same time) shared pixmap.  Which
    Jiang> means, one application create a GdkPixmap and pass the
    Jiang> address of it to another application, so the other
    Jiang> application can use that GdkPixmap.

    Jiang> I can successfully pass the address to different
    Jiang> application, but other application who do not create that
    Jiang> GdkPixmap can not use that.  So I wonder, whehter there is
    Jiang> osme way to do that?

If I understand you correctly, you want an application to provide
pixmap caching for other apps.  For a single xpm you want all your
apps to use a single pixmap.  It is important to note that the
GdkPixmap doesn't have the image data, so sharing that is not really
important.  The _server_ side pixmap is what needs to be shared as it
has the actual image data.

I really doubt gtk allows you to share gtk/gdk objects between
processes via shared memory.  This is roughly equivalent to using
threads in a single gtk/gdk application and raises all the same
locking issues.  So I don't think you are going to make this work by
trying to share the GdkPixmap.

I would get the XID of the GdkPixmap and try to build a new GdkPixmap
from that XID.  The actual _server_ side object will be the same.  I
don't know how to get gdk to make a GdkPixmap from an XID, but you
could ask around.  I think it will take some gdk hacking though as you
basically need a gdk_pixmap_create_from_xid() function.

You _might_ run into problems with this approach as well if gdk is
using the shared memory extension to deal with pixmaps.

Pablo