Add image previews to lf

home/.config/lf/clear_img.sh

@@ -0,0 +1,6 @@
+#!/bin/sh
+
+readonly PREVIEW_ID="preview"
+
+printf '{"action": "remove", "identifier": "%s"}\n' "$PREVIEW_ID" > "$FIFO_UEBERZUG"
+

home/.config/lf/draw_img.sh

@@ -0,0 +1,11 @@
+#!/bin/sh
+
+readonly PREVIEW_ID="preview"
+
+printf '{"action": "add", "identifier": "%s", "x": %d, "y": %d, "width": %d, "height": %d, "scaler": "contain", "scaling_position_x": 0.5, "scaling_position_y": 0.5, "path": "%s"}\n' \
+    "$PREVIEW_ID" "$2" "$3" "$4" "$5" "$1" > "$FIFO_UEBERZUG"
+
+#declare -p -A cmd=([action]=add [identifier]="$PREVIEW_ID" \
+#   [x]="$2" [y]="$3" [max_width]="$4" [max_height]="$5" \
+#   [path]="$1") > "$FIFO_UEBERZUG"
+

home/.config/lf/lfrc

@@ -1,5 +1,6 @@
 # Basic settings
-set previewer ~/.config/lf/previewer
+set previewer ~/.config/lf/previewer.sh
+set cleaner ~/.config/lf/clear_img.sh
 set preview true
 set hidden true
 set drawbox true

home/.config/lf/previewer.sh

@@ -0,0 +1,129 @@
+#!/bin/sh
+# This script handles showing file-previews within lf.
+# It can also show image previews using ueberzug, however
+# that requires lf to be start with a script that also starts
+# ueberzug alongside of it.
+# (In my dotfiles, this script is in '~/.local/bin/scripts/lfu')
+
+run_cmd() {
+    # Try to run given command, if it is installed.
+    # If it isn't try to fallback to text_handle,
+    # otherwise fail completely.
+    cmd="$1"
+    shift
+
+    if command -v "$cmd" > /dev/null; then
+        $cmd $@
+    else
+        # If we didn't found the requested command, check if
+        # the file is text-like and try to use the text_handle
+        # to show the preview, this may not be ideal for given
+        # file-format, but at least we won't fail.
+        case $(file --mime-type "$1" -bL) in
+            # TODO: Consider checking for UTF-8 formatting instead,
+            # or show previews for any file-type
+            text/*|application/json)
+                echo "@@PREVIEW FALLBACK: Using text handle, $cmd command not found!"
+                text_handle "$1"
+                ;;
+            *)
+                echo "@@PREVIEW ERROR: Preview failed, $cmd command not found!"
+                ;;
+        esac
+    fi
+}
+
+draw_image() {
+    # Draw passed image with use of given draw_script.
+    # If the image contains EXIF (metadata) orientation info,
+    # handle it and draw the rotated image.
+    draw_script="$1"
+    file="$2"
+    shift
+    shift
+
+    # Calculate where the image should be placed on the screen.
+    num=$(printf "%0.f\n" "`echo "$(tput cols) / 2" | bc`")
+    numb=$(printf "%0.f\n" "`echo "$(tput cols) - $num - 1" | bc`")
+    numc=$(printf "%0.f\n" "`echo "$(tput lines) - 2" | bc`")
+
+    # Handle EXIF (metadata) orientation.
+    exif_orientation="$(identify -format '%[EXIF:Orientation]\n' -- "$file")"
+    if [ -n "$exif_orientation" ] && [ "$exif_orientation" != 1 ]; then
+        # In case `convert` command isn't aviable, ignore EXIF rotation
+        if command -v convert > /dev/null; then
+            cache=$(mktemp /tmp/thumbcache.XXXXX)
+            convert -- "$file" -auto-orient "$cache"
+            $draw_script "$cache" $num 1 $numb $numc
+        else
+            $draw_script "$file" $num 1 $numb $numc
+        fi
+    else
+        $draw_script "$file" $num 1 $numb $numc
+    fi
+
+    # Exit with status code 1 to signal lf that the function
+    # should be re-ran next time instead of caching the result.
+    exit 1
+}
+
+image_handle() {
+    # Control function for showing/cleaning image previews
+    draw_script="${XDG_CONFIG_HOME:-$HOME/.config}/lf/draw_img.sh"
+    file="$1"
+    shift
+
+    if [ -n "$FIFO_UEBERZUG" ] && [ -f "$draw_script" ]; then
+        draw_image $draw_script $file
+    else
+        # Fallback to mediainfo preview
+        echo "@@PREVIEW FALLBACK: Using mediainfo, ueberzug isn't aviable."
+        run_cmd mediainfo "$file"
+    fi
+}
+
+text_handle() {
+    width="$(tput cols)"
+    echo "Limiting to $width"
+    # Handle all other formats as text and cat them
+    # if highlighting tools are aviable, try to use them
+    if command -v bat > /dev/null; then
+        bat -pp --color=always "$1"
+    elif command -v highlight > /dev/null; then
+        highlight "$1" --out-format ansi --force
+    else
+        cat "$1"
+    fi
+}
+
+# Capture all directories at first, since they could
+# potentionally match one of the file case statements
+if [ -d "$1" ]; then
+    tree "$1" -La 1
+elif [ -f "$1" ]; then
+    case "$1" in
+        *.tgz|*.tar.gz) run_cmd tar tzf "$1";;
+        *.tar.bz2|*.tbz2) run_cmd tar tjf "$1";;
+        *.tar.txz|*.txz) run_cmd xz --list "$1";;
+        *.tar) run_cmd tar tf "$1";;
+        *.zip|*.jar|*.war|*.ear|*.oxt) run_cmd unzip -l "$1";;
+        *.rar) run_cmd unrar l "$1";;
+        *.7z) run_cmd 7z l "$1";;
+        *.iso) run_cmd iso-info --no-header -l "$1";;
+        *.o) run_cmd nm "$1" | less ;;
+        *.csv) cat "$1" | sed s/,/\\n/g ;;
+        *odt,*.ods,*.odp,*.sxw) run_cmd odt2txt "$1";;
+        *.doc) run_cmd catdoc "$1" ;;
+        *.docx) run_cmd docx2txt "$1" - ;;
+        *.torrent) run_cmd transmission-show "$1";;
+        *.pdf) run_cmd pdftotext "$1";;
+        *.bmp|*.jpg|*.jpeg|*.png|*.xpm) image_handle "$1" ;;
+        *.wav|*.mp3|*.flac|*.m4a|*.wma|*.ape|*.ac3|*.og[agx]|*.spx|*.opus|*.as[fx]|*.flac) run_cmd exiftool "$1";;
+        *.avi|*.mp4|*.wmv|*.dat|*.3gp|*.ogv|*.mkv|*.mpg|*.mpeg|*.vob|*.fl[icv]|*.m2v|*.mov|*.webm|*.ts|*.mts|*.m4v|*.r[am]|*.qt|*.divx)
+            cache="$(mktemp /tmp/thumbcache.XXXXX)"
+            ffmpegthumbnailer -i "$1" -o "$cache" -s 0
+            image_handle "$cache"
+            ;;
+        *) text_handle "$1" ;;
+    esac
+fi