Improve roll_text from text_roll lib (#391)

* add new args 4 & 5, "fill_mode" and "repeat_sep"
* construct new repeat variable
* use length of repeat variable for offset calculation
  in case of fill_mode=repeat
* use repeat variable to fill free space
* remove byte calculation section, as real used "space"
  depends on font and leads to incorrect behaviour on
  some characters (e.g. french accent chars)
* smaller cleanup to comply with shellcheck
* use new mode as default in now_playing segment (but
  we don't change the default of the trim method)

fix #390

lib/text_roll.sh

@@ -1,7 +1,10 @@
+# shellcheck shell=bash
 # Rolling anything what you want.
 # arg1: text to roll.
 # arg2: max length to display.
 # arg3: roll speed in characters per second.
+# arg4: mode to fill {"space", "repeat"}
+# arg5: repeat separator
 roll_text() {
 	local text="$1"  # Text to print
 
@@ -21,6 +24,26 @@ roll_text() {
 		speed="$3"
 	fi
 
+	local fill_mode="space" # Default fill mode
+
+	if [ -n "$4" ]; then
+		if [ "$4" = "repeat" ]; then
+			fill_mode="repeat"
+		elif [ "$4" = "space" ]; then
+			fill_mode="space"
+		else
+			echo "Not a valid fill_mode: {\"space\", \"repeat\"}: $4" >&2
+		fi
+	fi
+
+	local repeat_sep=" ** " # Default repeat separator
+
+	if [ -n "$5" ]; then
+		repeat_sep="$5"
+	fi
+
+	local repeat="${repeat_sep}${text}"
+
 	# Skip rolling if the output is less than max_len.
 	if [ "${#text}" -le "$max_len" ]; then
 		echo "$text"
@@ -29,34 +52,26 @@ roll_text() {
 
 	# Anything starting with 0 is an Octal number in Shell,C or Perl,
 	# so we must explicitly state the base of a number using base#number
-	local offset=$((10#$(date +%s) * ${speed} % ${#text}))
-
-	# Truncate text.
+	if [ "$fill_mode" = "repeat" ]; then
+		local offset=$((10#$(date +%s) * speed % ${#repeat}))
+	elif [ "$fill_mode" = "space" ] || :; then
+		local offset=$((10#$(date +%s) * speed % ${#text}))
+	fi
+	# Truncate text on time-based offset
 	text=${text:offset}
 
-	local char	# Character.
-	local bytes # The bytes of one character.
-	local index
-
-	for ((index=0; index < max_len; index++)); do
-		char=${text:index:1}
-		bytes=$(echo -n $char | wc -c)
-		# The character will takes twice space
-		# of an alphabet if (bytes > 1).
-		if ((bytes > 1)); then
-			max_len=$((max_len - 1))
-		fi
-	done
-
+  # Ensure text is not longer than max_len
 	text=${text:0:max_len}
 
-	#echo "index=${index} max=${max_len} len=${#text}"
-	# How many spaces we need to fill to keep
-	# the length of text that will be shown?
-	local fill_count=$((${index} - ${#text}))
+	# Get fill count by substracting length of current text from max_len
+	local fill_count=$((max_len - ${#text}))
 
 	for ((index=0; index < fill_count; index++)); do
-		text="${text} "
+		if [ "$fill_mode" = "repeat" ]; then
+			text="${text}${repeat:index:1}"
+		elif [ "$fill_mode" = "space" ] || :; then
+			text="${text} "
+		fi
 	done
 
 	echo "${text}"

segments/now_playing.sh

@@ -5,6 +5,8 @@ source "${TMUX_POWERLINE_DIR_LIB}/text_roll.sh"
 TMUX_POWERLINE_SEG_NOW_PLAYING_MAX_LEN_DEFAULT="40"
 TMUX_POWERLINE_SEG_NOW_PLAYING_TRIM_METHOD_DEFAULT="trim"
 TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SPEED_DEFAULT="2"
+TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_MODE="${TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_MODE:-repeat}"
+TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SEPARATOR="${TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SEPARATOR:-   }"
 TMUX_POWERLINE_SEG_NOW_PLAYING_MPD_HOST_DEFAULT="localhost"
 TMUX_POWERLINE_SEG_NOW_PLAYING_MPD_PORT_DEFAULT="6600"
 TMUX_POWERLINE_SEG_NOW_PLAYING_LASTFM_UPDATE_PERIOD_DEFAULT="30"
@@ -25,8 +27,12 @@ export TMUX_POWERLINE_SEG_NOW_PLAYING_FILE_NAME=""
 export TMUX_POWERLINE_SEG_NOW_PLAYING_MAX_LEN="${TMUX_POWERLINE_SEG_NOW_PLAYING_MAX_LEN_DEFAULT}"
 # How to handle too long strings. Can be {trim, roll}.
 export TMUX_POWERLINE_SEG_NOW_PLAYING_TRIM_METHOD="${TMUX_POWERLINE_SEG_NOW_PLAYING_TRIM_METHOD_DEFAULT}"
-# Charcters per second to roll if rolling trim method is used.
+# Characters per second to roll if rolling trim method is used.
 export TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SPEED="${TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SPEED_DEFAULT}"
+# Mode of roll text {"space", "repeat"}. space: fill up with empty space; repeat: repeat text from beginning
+# export TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_MODE="${TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_MODE}"
+# Separator for "repeat" roll mode
+# export TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SEPARATOR="${TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SEPARATOR}"
 
 # Hostname for MPD server in the format "[password@]host"
 export TMUX_POWERLINE_SEG_NOW_PLAYING_MPD_HOST="${TMUX_POWERLINE_SEG_NOW_PLAYING_MPD_HOST_DEFAULT}"
@@ -113,7 +119,7 @@ run_segment() {
 	if [ -n "$np" ]; then
 		case "$TMUX_POWERLINE_SEG_NOW_PLAYING_TRIM_METHOD" in
 			"roll")
-				np=$(roll_text "${np}" ${TMUX_POWERLINE_SEG_NOW_PLAYING_MAX_LEN} ${TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SPEED_DEFAULT})
+				np=$(roll_text "${np}" ${TMUX_POWERLINE_SEG_NOW_PLAYING_MAX_LEN} ${TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SPEED_DEFAULT} ${TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_MODE} "${TMUX_POWERLINE_SEG_NOW_PLAYING_ROLL_SEPARATOR}")
 				;;
 			"trim")
 				np=${np:0:TMUX_POWERLINE_SEG_NOW_PLAYING_MAX_LEN}