Bug#1004711: gimp uses ebook-viewer (from calibre package) for print preview

[Simon McVittie]

On Mon, 31 Jan 2022 at 18:36:11 -0500, Eric Cooper wrote:
> I have both mupdf and calibre installed. When I choose File > Print,
> and then Print Preview, gimp launches the ebook-viewer program from
> calibre rather than mupdf, which appears before ebook-viewer in
> /etc/mailcap (if that matters).

The command used for print previews in GTK 2 comes from your GTK theme
(for historical reasons) or from gtkrc (several locations are searched,
~/.gtkrc-2.0 is the highest-priority).

Neither ebook-viewer nor mupdf is hard-coded anywhere in GTK or GIMP.
The only hard-coded command related to print previews is GNOME's evince,
which is used as a default if nothing else is configured.

Rather than /etc/mailcap, it is more likely that the print preview is
using your configured default PDF viewer according to this freedesktop.org
specification:
https://specifications.freedesktop.org/mime-apps-spec/latest/

You can configure the preferred PDF viewer for each user via
~/.config/mimeapps.list, or system-wide via /etc/xdg/mimeapps.list.

In a well-integrated desktop environment, defaults for several commonly-used
applications are in /usr/share/applications/DESKTOP-mimeapps.list, where
DESKTOP is the value of $XDG_CURRENT_DESKTOP transformed to lower-case.
For example, the GNOME desktop environment uses XDG_CURRENT_DESKTOP=GNOME,
and installs /usr/share/applications/gnome-mimeapps.list via the
gnome-session-common package.

/etc/mailcap is no longer used by most libraries and applications. It's
generated from freedesktop.org .desktop files by the update-mime command
for compatibility with libraries and applications that still use it,
but for historical reasons it has its own preference order.

    smcv