Thanks for this explanation. Unfortunately, I still can't find any place that's specifying ebook-viewer (or any PDF viewer, for that matter) among the various files you listed (none of which I've modified myself).
I purged calibre and tried the print preview again. Oddly, gimp still did not use mupdf, it used itself: it popped up the "import pdf" dialog for the pdf it was going to print, and opened a new (gimp) window for it. On Tue, Feb 1, 2022 at 5:22 AM Simon McVittie <s...@debian.org> wrote: > 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 >