--- /dev/null
+#!/bin/bash
+
+# Description: tabbed/xembed based file previewer
+#
+# Note: This plugin needs a "NNN_FIFO" to work. See man.
+#
+# Shell: Bash (job control is weakly specified in POSIX)
+#
+# Dependencies:
+# - tabbed (https://tools.suckless.org/tabbed): xembed host
+# - xterm (or urxvt or st) : xembed client for text-based preview
+# - mpv (https://mpv.io): xembed client for video/audio
+# - sxiv (https://github.com/muennich/sxiv): xembed client for images
+# - zathura (https://pwmt.org/projects/zathura): xembed client for PDF documents
+# - nnn's nuke plugin for text preview and fallback (should be in plugins directory)
+# nuke is a fallback for 'mpv', 'sxiv', and 'zathura', but it has has its own
+# dependencies, see the script itself
+# - vim (or any editor/pager really)
+# - file
+# - xdotool (optional, to keep main window focused)
+#
+# How to use:
+# First, install the dependencies. Then you need to set a NNN_FIFO path
+# and set a key for the plugin, then start `nnn`:
+#
+# $ NNN_FIFO=/tmp/nnn.fifo nnn
+#
+# Then in `nnn`, launch the `preview-tabbed` plugin.
+#
+# If you provide the same NNN_FIFO to all nnn instances, there will be a
+# single common preview window. I you provide different FIFO path, they
+# will be independent.
+#
+# How it works:
+# We use `tabbed` [1] as a xembed [2] host, to have a single window
+# owning each previewer window. So each previewer must be a xembed client.
+# For text previewers, this is not an issue, as there are a lot of
+# xembed-able terminal emulator (we default to `xterm`, but examples are
+# provided for `urxvt` and `st`). For graphic preview this can be trickier,
+# but a few popular viewers are xembed-able, we use:
+# - `mpv`: multimedia player, for video/audio preview
+# - `sxiv`: image viewer
+# - `zathura`: PDF viewer
+# - but we allways fallback to `nuke` plugin
+#
+# [1]: http://tools.suckless.org/tabbed/
+# [2]: https://specifications.freedesktop.org/xembed-spec/xembed-spec-latest.html
+
+
+XDOTOOL_TIMEOUT=2
+PAGER=${PAGER:-"vim -R"}
+NUKE="${XDG_CONFIG_HOME:-$HOME/.config}/nnn/plugins/nuke"
+
+
+if which xterm ; then
+ TERMINAL="xterm -into"
+elif which urxvt ; then
+ TERMINAL="urxvt -embed"
+elif which st ; then
+ TERMINAL="st -w"
+else
+ echo "No xembed term found" >&2
+fi
+
+
+term_nuke () {
+ # $1 -> $XID, $2 -> $FILE
+ $TERMINAL "$1" -e "$NUKE" "$2" &
+}
+
+start_tabbed () {
+ FIFO="$(mktemp -u)"
+ mkfifo "$FIFO"
+
+ tabbed > "$FIFO" &
+
+ jobs # Get rid of the "Completed" entries
+
+ TABBEDPID="$(jobs -p %%)"
+
+ if [ -z "$TABBEDPID" ] ; then
+ echo "Can't start tabbed"
+ exit 1
+ fi
+
+ read -r XID < "$FIFO"
+
+ rm "$FIFO"
+}
+
+get_viewer_pid () {
+ VIEWERPID="$(jobs -p %%)"
+}
+
+previewer_loop () {
+ unset -v NNN_FIFO
+ # mute from now
+ exec >/dev/null 2>&1
+
+ MAINWINDOW="$(xdotool getactivewindow)"
+
+ start_tabbed
+
+ xdotool windowactivate "$MAINWINDOW"
+
+ # Bruteforce focus stealing prevention method,
+ # works well in floating window managers like XFCE
+ # but make interaction with the preview window harder
+ # (uncomment to use):
+ #xdotool behave "$XID" focus windowactivate "$MAINWINDOW" &
+
+ while read -r FILE ; do
+
+ jobs # Get rid of the "Completed" entries
+
+ if ! jobs | grep tabbed ; then
+ break
+ fi
+
+ if [ ! -e "$FILE" ] ; then
+ continue
+ fi
+
+ if [ -n "$VIEWERPID" ] && jobs -p | grep "$VIEWERPID" ; then
+ kill "$VIEWERPID"
+ fi
+
+ MIME="$(file -b --mime-type "$FILE")"
+
+ case "$MIME" in
+ video/*)
+ if which mpv ; then
+ mpv --force-window=immediate --loop-file --wid="$XID" "$FILE" &
+ else
+ term_nuke "$XID" "$FILE"
+ fi
+ ;;
+ audio/*)
+ if which mpv ; then
+ mpv --force-window=immediate --loop-file --wid="$XID" "$FILE" &
+ else
+ term_nuke "$XID" "$FILE"
+ fi
+ ;;
+ image/*)
+ if which sxiv ; then
+ sxiv -e "$XID" "$FILE" &
+ else
+ term_nuke "$XID" "$FILE"
+ fi
+ ;;
+ application/pdf)
+ if which zathura ; then
+ zathura -e "$XID" "$FILE" &
+ else
+ term_nuke "$XID" "$FILE"
+ fi
+ ;;
+ inode/directory)
+ $TERMINAL "$XID" -e nnn "$FILE" &
+ ;;
+ text/*)
+ if [ -x "$NUKE" ] ; then
+ term_nuke "$XID" "$FILE"
+ else
+ # shellcheck disable=SC2086
+ $TERMINAL "$XID" -e $PAGER "$FILE" &
+ fi
+ ;;
+ *)
+ if [ -x "$NUKE" ] ; then
+ term_nuke "$XID" "$FILE"
+ else
+ $TERMINAL "$XID" -e sh -c "file '$FILE' | $PAGER -" &
+ fi
+ ;;
+ esac
+ get_viewer_pid
+
+ # following lines are not needed with the bruteforce xdotool method
+ ACTIVE_XID="$(xdotool getactivewindow)"
+ if [ $((ACTIVE_XID == XID)) -ne 0 ] ; then
+ xdotool windowactivate "$MAINWINDOW"
+ else
+ timeout "$XDOTOOL_TIMEOUT" xdotool behave "$XID" focus windowactivate "$MAINWINDOW" &
+ fi
+ done
+ kill "$TABBEDPID"
+}
+
+if [ ! -r "$NNN_FIFO" ] ; then
+ echo "Can't read \$NNN_FIFO ('$NNN_FIFO')"
+ exit 1
+fi
+
+previewer_loop < "$NNN_FIFO" &
+disown