Module: Rufio::TextUtils

Included in:
DialogRenderer
Defined in:
lib/rufio/text_utils.rb

Overview

Text utility methods for display width calculation and string manipulation Handles multi-byte characters (Japanese, etc.) correctly

Constant Summary collapse

FULLWIDTH_CHAR_WIDTH =

Character width constants

2
HALFWIDTH_CHAR_WIDTH = 
1
MULTIBYTE_THRESHOLD = 
1
ELLIPSIS_MIN_WIDTH =

Truncation constants

3
ELLIPSIS = 
'...'
BREAK_POINT_THRESHOLD =

Line break constants

0.5

Class Method Summary collapse

Class Method Details

.char_width(char) ⇒ Object

Calculate width for a single character with caching



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# File 'lib/rufio/text_utils.rb', line 25

def char_width(char)
  @char_width_cache[char] ||= begin
    case char
    when /[\u2500-\u257F]/
      HALFWIDTH_CHAR_WIDTH  # Box Drawing characters (罫線文字) - ターミナルでは幅1
    when /[\u3000-\u303F\u3040-\u309F\u30A0-\u30FF\u4E00-\u9FAF\uFF00-\uFFEF\u2580-\u259F]/
      FULLWIDTH_CHAR_WIDTH  # Japanese characters (hiragana, katakana, kanji, full-width symbols, block elements)
    when /[\u0020-\u007E]/
      HALFWIDTH_CHAR_WIDTH  # ASCII characters
    else
      char.bytesize > MULTIBYTE_THRESHOLD ? FULLWIDTH_CHAR_WIDTH : HALFWIDTH_CHAR_WIDTH
    end
  end
end

.display_width(string) ⇒ Object

Calculate display width of a string Full-width characters (Japanese, etc.) count as 2, half-width as 1



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# File 'lib/rufio/text_utils.rb', line 42

def display_width(string)
  width = 0
  string.each_char do |char|
    width += char_width(char)
  end
  width
end

.find_break_point(line, max_width) ⇒ Object

Find the best break point for wrapping text within max_width



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# File 'lib/rufio/text_utils.rb', line 97

def find_break_point(line, max_width)
  return line.length if display_width(line) <= max_width

  current_width = 0
  best_break_point = 0
  space_break_point = nil
  punct_break_point = nil

  line.each_char.with_index do |char, index|
    cw = char_width(char)
    break if current_width + cw > max_width

    current_width += cw
    best_break_point = index + 1

    # Record break point at space
    space_break_point = index + 1 if char == ' ' && current_width > max_width * BREAK_POINT_THRESHOLD

    # Record break point at Japanese punctuation
    punct_break_point = index + 1 if char.match?(/[、。，．！？]/) && current_width > max_width * BREAK_POINT_THRESHOLD
  end

  space_break_point || punct_break_point || best_break_point
end

.pad_string_to_width(string, target_width) ⇒ Object

Pad string to target_width with spaces



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# File 'lib/rufio/text_utils.rb', line 87

def pad_string_to_width(string, target_width)
  current_width = display_width(string)
  if current_width >= target_width
    truncate_to_width(string, target_width)
  else
    string + ' ' * (target_width - current_width)
  end
end

.truncate_to_width(string, max_width) ⇒ Object

Truncate string to fit within max_width



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# File 'lib/rufio/text_utils.rb', line 51

def truncate_to_width(string, max_width)
  return string if display_width(string) <= max_width

  # If max_width is enough for ellipsis, truncate and add ellipsis
  if max_width >= ELLIPSIS_MIN_WIDTH
    result = ''
    current_width = 0
    target_width = max_width - ELLIPSIS_MIN_WIDTH

    string.each_char do |char|
      cw = char_width(char)
      break if current_width + cw > target_width

      result += char
      current_width += cw
    end

    result + ELLIPSIS
  else
    # Not enough room for ellipsis, just truncate
    result = ''
    current_width = 0

    string.each_char do |char|
      cw = char_width(char)
      break if current_width + cw > max_width

      result += char
      current_width += cw
    end

    result
  end
end

.wrap_preview_lines(lines, max_width) ⇒ Array<String>

Wrap preview lines to fit within max_width

Parameters:

  • lines (Array<String>) —

    Lines to wrap

  • max_width (Integer) —

    Maximum width for each line

Returns:

  • (Array<String>) —

    Wrapped lines



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# File 'lib/rufio/text_utils.rb', line 126

def wrap_preview_lines(lines, max_width)
  return lines if max_width <= 0

  wrapped = []
  lines.each do |line|
    # Handle encoding errors: scrub invalid UTF-8 sequences
    begin
      # Force UTF-8 encoding and replace invalid bytes
      line = line.encode('UTF-8', invalid: :replace, undef: :replace, replace: '?')
      # Remove trailing whitespace
      line = line.rstrip
    rescue EncodingError, ArgumentError => e
      # If encoding fails completely, skip this line
      wrapped << '[encoding error]'
      next
    end

    # If line is empty, keep it
    if line.empty?
      wrapped << ''
      next
    end

    # If line fits within max_width, keep it as is
    begin
      if display_width(line) <= max_width
        wrapped << line
        next
      end
    rescue ArgumentError => e
      # If display_width fails, just truncate by byte length
      if line.bytesize <= max_width
        wrapped << line
        next
      end
    end

    # Split long lines
    current_line = []
    current_width = 0

    begin
      line.each_char do |char|
        cw = char_width(char)

        if current_width + cw > max_width
          # Start a new line
          wrapped << current_line.join
          current_line = [char]
          current_width = cw
        else
          current_line << char
          current_width += cw
        end
      end

      # Add remaining characters
      wrapped << current_line.join unless current_line.empty?
    rescue ArgumentError, EncodingError => e
      # If character iteration fails, just add the line truncated
      truncated = line.byteslice(0, [max_width, line.bytesize].min)
      wrapped << (truncated || line)
    end
  end

  wrapped
end