Bug#1080151: meta-gnome3: make a decision between eog and loupe for new trixie installations

[Jeremy Bícha]

I believe we should swap eog to loupe in gnome-core now.

I tested Loupe 47 (currently in Unstable) and it felt approximately
feature equivalent with eog.

- Screen reader support appeared to work as expected
- Image format support is different than how most GNOME-ish worked
before. Instead of gdk-pixbuf loaders, it uses glycin loaders.
Here is the list of formats that is supposed to work with Loupe in its
vendored state
https://gitlab.gnome.org/sophie-h/glycin#supported-image-formats
We ship it unvendored in Debian. Some differences: we haven't yet
enabled JPEG XL but I think that will be done in time for Trixie.
We don't support OpenEXR but that feels like a fairly obscure format
to me. Every other format in that list should work for display (the
other checkmarks are for specific features for those formats.

On Sat, Aug 31, 2024 at 12:51 AM Phil Wyett <philip.wyett at kathenas.org> wrote:
> My only concern with replacing eog with loupe, is that you cannot tell what
> zoom level you are at in loupe. This can get rather confusing unlike with eog
> where it is visible in the UI and easily changed.

This appears to be fixed in main for Loupe 48. GNOME 48 will be too
late for inclusion in Debian 13 given expected freeze dates.
https://blogs.gnome.org/sophieh/2024/09/20/image-viewing-and-editing-in-gnome-47-and-beyond/

I am looking forward to Loupe 48 since that release might be the first
to support cropping which eog never supported.

I think in general gnome-core should reflect what GNOME determines to
be in GNOME Core unless we have a good reason to diverge and I don't
think we do here now.

I intend to not provide an alternate dependency for eog. An alternate
dependency would mean that upgraders would not get our new default.
Until we have some kind of upgrade script, alternate dependencies for
changed defaults seems unworkable.

Thank you,
Jeremy Bícha