Add BOLLUX_PRE_DISPLAY and functionality (fix #1)

Configuration option: BOLLUX_PRE_DISPLAY
- comma-separated list of following options: 'pre', 'alt', 'both'
- default: 'pre,alt,both'

Keybind: `
- when pressed, will cycle through the options in BOLLUX_PRE_DISPLAY

Full documentation coming in the next commit.

bollux

@@ -50,6 +50,20 @@ trim_string() { # trim_string STRING
 	printf '%s\n' "$_"
 }
 
+# cycle a variable, e.g. from 'one,two,three' => 'two,three,one'
+cycle_list() { # cycle_list LIST DELIM
+	local list="${!1}" delim="$2"
+	local first="${list%%${delim}*}"
+	local rest="${list#*${delim}}"
+	printf -v "$1" '%s%s%s' "${rest}" "${delim}" "${first}"
+}
+
+# determine the first element of a list, e.g. 'one,two,three' => 'one'
+first() { # first LIST DELIM
+	local list="${!1}" delim="$2"
+	printf '%s\n' "${list%%${delim}*}"
+}
+
 log() { # log LEVEL MESSAGE
 	[[ "$BOLLUX_LOGLEVEL" == QUIET ]] && return
 	local fmt
@@ -122,6 +136,7 @@ bollux_config() {
 	: "${BOLLUX_PROTO:=gemini}"                    # default protocol
 	: "${BOLLUX_URL:=}"                            # start url
 	: "${BOLLUX_BYEMSG:=See You Space Cowboy ...}" # bye message
+	: "${BOLLUX_PRE_DISPLAY:=pre,alt,both}"        # how to view PRE blocks
 	## files
 	: "${BOLLUX_DATADIR:=${XDG_DATA_DIR:-$HOME/.local/share}/bollux}"
 	: "${BOLLUX_DOWNDIR:=.}"                       # where to save downloads
@@ -720,7 +735,7 @@ less_prompt_escape() { # less_prompt_escape STRING
 
 # generate a lesskey(1) file for custom keybinds
 mklesskey() { # mklesskey FILENAME
-	lesskey -o "$1" - <<-END
+	lesskey -o "$1" - <<-\END
 		#command
 		o quit 0 # 48 open a link
 		g quit 1 # 49 goto a url
@@ -728,8 +743,9 @@ mklesskey() { # mklesskey FILENAME
 		] quit 3 # 51 forward
 		r quit 4 # 52 re-request / download
 		G quit 5 # 53 goto a url (pre-filled)
+		` quit 6 # 54 cycle BOLLUX_PRE_DISPLAY and refresh
 		# other keybinds
-		\\40 forw-screen-force
+		\40 forw-screen-force
 		h left-scroll
 		l right-scroll
 		? status   # 'status' will show a little help thing.
@@ -767,15 +783,26 @@ typeset_gemini() {
 
 	log d "T_WIDTH=$T_WIDTH"
 	log d "WIDTH=$WIDTH"
+	log d "$BOLLUX_PRE_DISPLAY"
 
 	while IFS= read -r; do
 		case "$REPLY" in
 		'```'*)
+			PRE_LINE_FORCE=false
 			if $pre; then
 				pre=false
 			else
 				pre=true
 			fi
+			case "${BOLLUX_PRE_DISPLAY%%,*}" in
+			pre)
+				:
+				;;
+			alt | both)
+				$pre && PRE_LINE_FORCE=true \
+					gemini_pre "${REPLY#\`\`\`}"
+				;;
+			esac
 			continue
 			;;
 		'=>'*)
@@ -881,8 +908,12 @@ gemini_text() {
 }
 
 gemini_pre() {
-	printf "\e[${C_SIGIL}m%${S_MARGIN}s " '```'
-	printf "\e[${C_PRE}m%s${C_RESET}\n" "$1"
+	# Print preformatted text, dependent on $BOLLUX_PRE_DISPLAY and
+	# $PRE_LINE_FORCE
+	if [[ alt != "${BOLLUX_PRE_DISPLAY%%,*}" ]] || $PRE_LINE_FORCE; then
+		printf "\e[${C_SIGIL}m%${S_MARGIN}s " '```'
+		printf "\e[${C_PRE}m%s${C_RESET}\n" "$1"
+	fi
 }
 
 # wrap lines on words to WIDTH
@@ -976,7 +1007,11 @@ handle_keypress() { # handle_keypress CODE
 		run prompt -u GO
 		run blastoff -u "$REPLY"
 		;;
-	*) # 54-57 -- still available for binding
+	54) # ` - change alt-text visibility and refresh
+		run cycle_list BOLLUX_PRE_DISPLAY ,
+		run blastoff "$BOLLUX_URL"
+		;;
+	55) # 55-57 -- still available for binding
 		die "$?" "less(1) error"
 		;;
 	esac