Implemented reflow for plaintexts in the client itself

README.md

@@ -6,7 +6,7 @@
 
 ## What is it?
 
-Bopher-NG is an ambitious attempt to write a full-featured Gopher client/browser in under 300 SLOC of pure Bash code. It started off as a really crude and unoptimized prototype developed right in [this blog post](https://chronovir.us/2023/03/28/I-wrote-a-browser/) for educational purposes.
+Bopher-NG is an ambitious attempt to write a full-featured Gopher client/browser in under 350 SLOC of pure Bash code. It started off as a really crude and unoptimized prototype developed right in [this blog post](https://chronovir.us/2023/03/28/I-wrote-a-browser/) for educational purposes.
 
 Improvements over the original Bopher from that post:
 
@@ -14,6 +14,7 @@ Improvements over the original Bopher from that post:
 - smoother rendering and scrolling
 - better edge-case stability (e.g. on macOS where using file descriptor 3 actually crashes everything)
 - better Gophermap processing according to the RFC1436
+- an actual text reflow when viewing plaintext documents with no hard wrapping
 - multi-level navigation history (although you can only go back)
 - status bar with currently opened resource name
 - ability to accept `gopher://` URLs from the command line

bopher-ng.sh

@@ -8,6 +8,7 @@
 # - smoother rendering and scrolling
 # - better edge-case stability
 # - better Gophermap processing according to the RFC1436
+# - an actual text reflow when viewing plaintext documents with no hard wrapping
 # - multi-level navigation history (although you can only go back)
 # - status bar with currently opened resource name
 # - ability to accept gopher:// URLs from the command line
@@ -121,6 +122,38 @@ gmparse() { # args: line, curhost, curport
   printf '%s\t%s\t%s\t%s\t%s\t%s\n' "$action" "$desc" "$rhost" "$rport" "$sel" "$rtype" # output the final formatted line
 }
 
+phlow_lite() { # a single-parameter line reflow algorithm
+  local line="$1"
+  local TARGET_WIDTH="$2"
+  local reflowfmt="%-${TARGET_WIDTH}s\n"
+  local llen="${#line}" # get effective line length
+  if (( 0 == TARGET_WIDTH || llen < TARGET_WIDTH )); then # no need to run the logic for smaller lines or if TARGET_WIDTH is 0
+    printf "$reflowfmt" "$line"
+    return
+  fi
+  local lastws=0 # variable to track last whitespace
+  local cpos=0 # variable to track current position within the page line
+  local pagepos=0 # variable to track the position of new line start
+  local outbuf='' # temporary output buffer
+  local c='' # temporary character buffer
+  for ((i=0;i<llen;i++,cpos++)); do # start iterating over characters
+    if (( cpos >= TARGET_WIDTH )); then # we already exceeded the page width
+      (( lastws == 0 )) && lastws=$TARGET_WIDTH # no whitespace encountered here
+      printf "$reflowfmt" "${outbuf:0:$lastws}" # truncate the buffer
+      outbuf=''
+      pagepos=$(( pagepos + lastws ))
+      cpos=0
+      lastws=0
+      i=$pagepos # update current iteration index from the last valid whitespace
+    else # save the whitespace position if found
+      c="${line:i:1}" # get the current character
+      [[ "$c" == $'\x20' ]] && lastws="$cpos"
+      outbuf="${outbuf}${c}" # save the character itself
+    fi
+  done
+  [[ ! -z "$outbuf" ]] && printf "$reflowfmt" "$outbuf" # output the last unprocessed chunk
+}
+
 # convert AM line back to gopher:// URL
 amtogopher() { # args: AM line
   readarray -d $'\t' -t fields < <(printf '%s' "$1")
@@ -159,9 +192,13 @@ amclick() { # args: AM line[, forcedl], output: AM line(s)
       gmparse "$line" "$rhost" "$rport"
     done
   elif [[ 'P' == "$action" ]]; then # plain text content (can be delimited with both CRLF or LF)
+    read -r TERMROWS TERMCOLS < <(stty size) # get current terminal size info
     readarray -t lines -d $'\n' < <(gophetch "$rhost" "$rport" "$puresel" "$input") # split on LF
     for line in "${lines[@]}"; do # iterate over every fetched line
-      printf 'E\t%s\n' "${line%%$'\r'}" # remove a trailing CR if it's there 
+      readarray -t reflow_lines -d $'\n' < <(phlow_lite "${line%%$'\r'}" "$TERMCOLS") # remove a trailing CR if it's there 
+      for rline in "${reflow_lines[@]}"; do
+        printf 'E\t%s\n' "$rline"
+      done
     done
   fi
 }
@@ -309,7 +346,6 @@ readmouseinput() { # correctly read the remaining mouse input in semi-long mode
   printf '%d %d %d %c\n' "$battr" "$mx" "$my" "$c"
 }
 
-
 # entry point code starts here
 
 printf '%s' "$ALTBUFON$CLS" # enter ALTBUF mode and clear the screen