Re: Evince as universal "Viewer"

[Jonathan Blandford <jrb redhat com>]

Steven Garrity <stevelist silverorange com> writes:

> Someone mentioned Evince in the discussion and it made me wonder:
> should Evince replace Eye of Gnome as the universal "Viewer" app on
> Gnome. It already seems to support the basic image formats (jpeg, png,
> etc.).

No.

The two are fundamentally different applications.  They are somewhat
similar to the user, but they make entirely different tradeoffs.  Eog is
an image viewer, and is designed around displaying a pixel-based image.
Evince is a document browser, and is designed around displaying
primarily vectorized formats.  The image support for evince was added
primarily for tiffs, and will probably be removed as GdkPixbuf doesn't
support multi-page tiffs.

Here are some big differences:

 * images have a 'natural' size.  Evince assumes the document can be
   viewed at any size, which is often really wrong for images.

 * evince's navigation is centered around going linearly through a
   document -- eog is based on random access to an image.  eg, a good
   default for an image would be to zoom it to fit so you can see the
   whole thing.  For a document, you want to be zoomed in to a readable
   size, which might not show the whole doc.

 * eog always has the source image around, and can do neat tricks while
   scrolling/zooming.  Evince has to do an entirely different set of
   tricks.

 * evince caches a different set of images than eog does.

 * documents will have a different set of metadata than images and
   photos do.

There are also few user visible gains to be had from merging the
projects.  There's already sharing of code and ideas between the various
projects (such as the full-screen mode, etc).  Lets let Jens continue to
make a kick-ass image viewer, and let the evince team focus on making a
good document viewer.

Thanks,
-Jonathan