lf: add theme and previewer

user/lf/previewer

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+MIME=$(mimetype --all --brief "$1")
+#echo "$MIME"
+
+case "$MIME" in
+    # .pdf
+    *application/pdf*)
+        pdftotext "$1" -
+        ;;
+    # .7z
+    *application/x-7z-compressed*)
+        7z l "$1"
+        ;;
+    # .tar .tar.Z
+    *application/x-tar*)
+        tar -tvf "$1"
+        ;;
+    # .tar.*
+    *application/x-compressed-tar*|*application/x-*-compressed-tar*)
+        tar -tvf "$1"
+        ;;
+    # .rar
+    *application/vnd.rar*)
+        unrar l "$1"
+        ;;
+    # .zip
+    *application/zip*)
+        unzip -l "$1"
+        ;;
+    # any plain text file that doesn't have a specific handler
+    *text/plain*)
+        # return false to always repaint, in case terminal size changes
+        bat --force-colorization --paging=never --style=changes,numbers \
+            --terminal-width $(($2 - 3)) "$1" && false
+        ;;
+    *)
+        echo "unknown format"
+        ;;
+esac