doc

Signed-off-by: Mattias Andrée <maandree@operamail.com>

1 files changed, 40 insertions, 16 deletions

diff --git a/src/splashtool b/src/splashtool
index 2fc1c10..e7f317c 100755
--- a/src/splashtool
+++ b/src/splashtool
@@ -25,6 +25,7 @@ d="$(dirname "$(realpath "$0")")"
 cd "$(dirname "$1")"
 
 
+# Create an images from the generated data.
 make_image ()
 {
     if [ -z "${debug}" ]; then
@@ -93,7 +94,11 @@ csel ()
 # Truncate the number of lines, and fill in missing lines
 ltrunc ()
 {
-    (cat ; awk "BEGIN { for (i=0; i<${1}; i++) print \" \"; }") | sed ${1}q
+    if [ ${1} = 0 ]; then
+	cat >/dev/null
+    else
+	(cat ; awk "BEGIN { for (i=0; i<${1}; i++) print \" \"; }") | sed ${1}q
+    fi
 }
 
 # Truncate the number of columns, and fill in missing columns
@@ -115,15 +120,21 @@ cset ()
     sed -e 's/^/\x1b'"$(csel "${1}")"'\x1b/' -e 's/$/\x1b\x1b/'
 }
 
+# Replace horizontal tab space with blank space and trim comments and whitespace.
 data="$(sed -e 's/\t/ /g' < "$in" | sed -e '/^ *\(#\|$\)/d' -e 's/ # .*$//' -e 's/^ *//' -e 's/ *$//')"
+# Get help message for the first menu entry.
 helptext="$(echo "${data}" | get_text)"
-data="$((default_data ; echo "${data}") | grep -Pi '^(timeout|menu|font) ' | tac)"
-data="$(echo "${data}" | sed -e 's/^MENU //' -e 's/^COLOR /COLOR_/')"
+# Get get information that we will use.
+data="$((default_data ; echo "${data}") | grep -Pi '^(timeout|menu|font) ')"
+# Format `data` so it can be easily parsed.
+data="$(echo "${data}" | tac | sed -e 's/^MENU //' -e 's/^COLOR /COLOR_/')"
+# Get menu entry labels.
 labels="$(echo "${data}" | tac | grep -i '^label ' | sed -e 's/^..... //')"
 
+# Preload some data and make things available to subshells.
 export data
-
 export font="$(sel font)"
+export title="$(sel title)"
 export width="$(sel width)"
 export vshift="$(sel vshift)"
 export helpmsgendrow="$(( $(sel helpmsgendrow) - ${vshift} ))"
@@ -131,20 +142,26 @@ export helpmsgrow="$(sel helpmsgrow)"
 export menumargin=$(( (${width} - 70) / 2 ))
 export border="$(csel color_border)"
 
+# Make image.
 (
+# Print background image, screen width (columns), and screen heights (lines)
 echo "$(sel background)"
 echo "${width}"
 echo "29"
 
+# Format menu labels.
 labels="$(echo "${labels}" | ltrunc "$(sel rows)" | sed -e 's/^/ /' | ctrunc 68)"
 labels="$(echo "${labels}" | sed -e 1q | cset color_sel ; echo "${labels}" | sed -e 1d | cset color_unsel)"
 
+# Format title.
 title="$(echo "${title}" | padl $(( (68 - $(echo -n "${title}" | wc -c)) / 2 )) | ctrunc 68 | cset color_title)"
 
+# Format help message.
 helptext="$(echo "${helptext}" | ltrunc $(( ${helpmsgendrow} - ${helpmsgrow} + 1 )) | padl $(sel margin))"
 helptext="$(echo "${helptext}" | ctrunc "${width}" | cset color_help)"
 
-text_ ()
+# Generate the menu.
+menu_ ()
 {
     line="$(printf "%68s" "" | sed -e 's/ /─/g')"
     echo "┌${line}┐"
@@ -154,16 +171,20 @@ text_ ()
     echo "└${line}┘"
 }
 
+# Add more things to print.
 add_more ()
 {
     echo "${more}" ; echo "${1}" | sed -e "s/^/"$(( $(sel ${2}) * 10 + ${3} ))" /"
 }
 
-text="$(echo "${labels}" | text_ | cset color_border | padl ${menumargin})"
+# Add menu.
+text="$(echo "${labels}" | menu_ | cset color_border | padl ${menumargin})"
 text="$(awk "BEGIN { for (i=0; i<${vshift}; i++) print \" \"; }" ; echo "${text}")"
 
+# Addition stuff.
 export more=""
 
+# Add timeout counter.
 if [ ! "$(sel timeout)" = 0 ]; then
     timeout=$(( $(sel timeout) / 10 ))
     timeoutmsg_="Automatic boot in ${timeout} seconds"
@@ -174,31 +195,31 @@ if [ ! "$(sel timeout)" = 0 ]; then
     export more="$(add_more "${timeoutmsg}" timeoutrow 0)"
 fi
 
+# Add "Press [Tab] to edit options", not visible if there is a timeout counter.
 tabmsg="Press [Tab] to edit options"
 tabmsg="$(echo "${tabmsg}" | padl $(( (${width} - $(echo -n "${tabmsg}" | wc -c)) / 2 )) | cset color_tabmsg)"
 export more="$(add_more "${tabmsg}" tabmsgrow 1)"
+# Add the help message
 export more="$(add_more "${helptext}" helpmsgrow 2)"
+
+# Sort (using a stable algorithm) `more` by the items' line indices.
 more="$(echo "${more}" | sed -e 1d | sort -n -s -k 1,1)"
 
+# Print addition stuff (`more`).
 export text
 segs ()
 {
     line=$(( $(echo "${text}" | wc -l) - $(sel vshift) ))
     last=0
-    mod=0
     while read -r seg; do
 	current=$(echo "${seg}" | cut -d ' ' -f 1)
 	index=$(( ${current} / 10 - 1 ))
 	seg="$(echo "${seg}" | sed -e 's/^[^ ]* //')"
 	if [ ${last} = ${current} ]; then
-	    text="$(echo "${text}" ; echo "${seg}")"
-	    line=$(( ${index} + 1 ))
-	elif (( ${line} <= ${index} )); then
-	    if (( ${line} < ${index} )); then
-		text="$(echo "${text}" ; echo -n | ltrunc $(( ${index} - ${line} )) ; echo "${seg}")"
-	    else
-		text="$(echo "${text}" ; echo "${seg}")"
-	    fi
+	    line=index
+	fi
+	if (( ${line} <= ${index} )); then
+	    text="$(echo "${text}" ; echo -n | ltrunc $(( ${index} - ${line} )) ; echo "${seg}")"
 	    line=$(( ${index} + 1 ))
 	fi
 	last=${current}
@@ -207,8 +228,11 @@ segs ()
 }
 text="$(echo "${more}" | segs | ltrunc 29)"
 
+# Print the image data.
 if [ -z "${debug}" ]; then
+    # Print the overlay.
     echo "${text}"
+    # Print the font.
     (
 	if echo "${font}" | grep -i '.gz$' 2>/dev/null >/dev/null; then
 	    psf2txt <(gunzip < "${font}") /dev/stderr
@@ -217,8 +241,8 @@ if [ -z "${debug}" ]; then
 	fi
     ) 2>&1 >/dev/null | grep -v ++
 else
+    # Print the overlay with ANSI colours.
     echo "${text}" | sed -e 's/\x1b\([^\x1b]*\)\x1b/\x1b[\1m/g'
 fi
-
 ) | make_image