refactor: use ueberzugpp and improve img preview methods

lib/file_preview.sh

@@ -1,12 +1,15 @@
 #! /usr/bin/env sh
 mime=$(file -bL --mime-type "$1")
 category=${mime%%/*}
+command -v ueberzugpp >/dev/null 2>&1 && [ -n "$UEBERZUGPP_SOCKET" ] && ub_avail="yes"
 if [ -d "$1" ]; then
+    [ "$ub_avail" = "yes" ] && bash $OMZ/lib/img_preview.sh remove
     exa -l --no-user --no-time --icons --no-permissions --no-filesize "$1" 2>/dev/null || ls --color=always "$1" 2>/dev/null || ls -G "$1"
 elif [ "$category" = text ]; then
+    [ "$ub_avail" = "yes" ] && bash $OMZ/lib/img_preview.sh remove
     (bat -p --color=always "$1" || cat "$1") 2>/dev/null | head -1000
 elif [ "$category" = image ]; then
-    command -v ueberzug 2&>/dev/null && bash $OMZ/lib/img_preview.sh "$1"|| img2txt "$1"
+    [ "$ub_avail" = "yes" ] && bash $OMZ/lib/img_preview.sh draw "$1"|| img2txt "$1"
 else 
     echo $1 is a $category file
     (bat -p --color=always "$1" || cat "$1") 2>/dev/null | head -1000

lib/img_preview.sh

@@ -1,28 +1,8 @@
 #!/usr/bin/env bash
 
 declare -r -x DEFAULT_PREVIEW_POSITION="right"
-declare -r -x UEBERZUG_FIFO="$(mktemp --dry-run --suffix "fzf-$$-ueberzug")"
 declare -r -x PREVIEW_ID="preview"
 
-function start_ueberzug {
-    mkfifo "${UEBERZUG_FIFO}"
-    <"${UEBERZUG_FIFO}" \
-        ueberzug layer --parser bash --silent &
-    3>"${UEBERZUG_FIFO}" \
-        exec
-}
-
-function finalise {
-    3>&- \
-        exec
-    &>/dev/null \
-        rm "${UEBERZUG_FIFO}"
-    &>/dev/null \
-        kill $(jobs -p)
-    killall ueberzug
-}
-
-function draw_preview {
 source $OMZ/cache/cursor
 X=$(($COLUMNS / 2 + 2))
 Y=$((row + 2))
@@ -30,15 +10,17 @@ function draw_preview {
     Y=$((LINES - 11))
 fi
 
-    >"${UEBERZUG_FIFO}" declare -A -p cmd=( \
-        [action]=add [identifier]="${PREVIEW_ID}" \
-        [x]="${X}" [y]="${Y}" \
-        [width]="$(($COLUMNS / 2 - 2))" [height]="10" \
-        [scaler]=forced_cover [scaling_position_x]=0.5 [scaling_position_y]=0.5 \
-        [path]="${@}")
+function draw_preview {
+    ueberzugpp cmd -s $UEBERZUGPP_SOCKET -i $PREVIEW_ID -a add \
+        -x $X -y $Y --max-width $(($COLUMNS / 2 - 2)) --max-height 10 \
+        -f ${@}
 }
 
-trap finalise EXIT
-start_ueberzug
-draw_preview $*
-sleep 999999
+function remove_preview {
+    ueberzugpp cmd -s $UEBERZUGPP_SOCKET -i $PREVIEW_ID -a remove
+}
+
+case "$1" in
+	draw) shift; draw_preview $* ;;
+	remove) remove_preview ;;
+esac

omz.zsh

@@ -1,4 +1,5 @@
 export OMZ=$(cd $(dirname $0);pwd)
+export UEBERZUGPP_PID_FILE=$OMZ/cache/ubpidfile
 source $OMZ/config/omz.zsh
 source $OMZ/config/git.zsh
 source $OMZ/config/fzf.zsh

plugins/fzf-tab/fzf-tab.zsh

@@ -87,6 +87,27 @@
   builtin compadd -U -qS '' -R -ftb-remove-space ''
 }
 
+# try to start and stop fzf and ueberzugpp simultaneously
+-ftb-start-ueberzugpp() {
+	case "$(uname -a)" in
+		*Darwin*) ub_tmp_dir="$TMPDIR" ;;
+		*) ub_tmp_dir="/tmp" ;;
+	esac
+
+	if command -v ueberzugpp >/dev/null 2>&1; then
+		ueberzugpp layer --no-stdin -so x11 --pid-file "$UEBERZUGPP_PID_FILE"
+		ub_pid=$(cat "$UEBERZUGPP_PID_FILE")
+		export UEBERZUGPP_SOCKET="$ub_tmp_dir"/ueberzugpp-"$ub_pid".socket
+	fi
+}
+
+-ftb-stop-ueberzugpp() {
+	if [[ -n "$UEBERZUGPP_SOCKET" && -S "$UEBERZUGPP_SOCKET" ]]; then
+		ueberzugpp cmd -s "$UEBERZUGPP_SOCKET" -a "exit"
+		unset UEBERZUGPP_SOCKET
+	fi
+}
+
 # when insert multi results, a whitespace will be added to each result
 # remove left space of our fake result because I can't remove right space
 # FIXME: what if the left char is not whitespace: `echo $widgets[\t`
@@ -132,9 +153,11 @@
       -ftb-zstyle -s print-query print_query || print_query=alt-enter
       -ftb-zstyle -s accept-line accept_line
 
+			-ftb-start-ueberzugpp
       choices=("${(@f)"$(builtin print -rl -- $_ftb_headers $_ftb_complist | -ftb-fzf)"}")
       ret=$?
       # choices=(query_string expect_key returned_word)
+			-ftb-stop-ueberzugpp
 
       # insert query string directly
       if [[ $choices[2] == $print_query ]] || [[ -n $choices[1] && $#choices == 1 ]] ; then