Module: Shellfie::TextMetrics

Defined in:
lib/shellfie/text_metrics.rb

Constant Summary collapse

UNICODE_VERSION = 
RbConfig::CONFIG["UNICODE_VERSION"] || "unknown"
WIDTH_TABLE_VERSION = 
"1"
AMBIGUOUS_RANGES = 
[
  0x00a1..0x00a1, 0x00a4..0x00a4, 0x00a7..0x00a8, 0x00aa..0x00aa, 0x00ad..0x00ae,
  0x00b0..0x00b4, 0x00b6..0x00ba, 0x00bc..0x00bf, 0x00c6..0x00c6, 0x00d0..0x00d0,
  0x00d7..0x00d8, 0x00de..0x00e1, 0x00e6..0x00e6, 0x00e8..0x00ea, 0x00ec..0x00ed,
  0x00f0..0x00f0, 0x00f2..0x00f3, 0x00f7..0x00fa, 0x00fc..0x00fc, 0x00fe..0x00fe,
  0x0101..0x0101, 0x0111..0x0113, 0x011b..0x011b, 0x0126..0x0127, 0x012b..0x012b,
  0x0131..0x0133, 0x0138..0x0138, 0x013f..0x0142, 0x0144..0x0144, 0x0148..0x014b,
  0x014d..0x014d, 0x0152..0x0153, 0x0166..0x0167, 0x016b..0x016b, 0x01ce..0x01dc,
  0x0251..0x0251, 0x0261..0x0261, 0x02c4..0x02c4, 0x02c7..0x02c7, 0x02c9..0x02cb,
  0x02cd..0x02d0, 0x02d8..0x02db, 0x02dd..0x02df, 0x0391..0x03a1, 0x03a3..0x03a9,
  0x03b1..0x03c1, 0x03c3..0x03c9, 0x0401..0x0401, 0x0410..0x044f, 0x0451..0x0451,
  0x2010..0x2010, 0x2013..0x2016, 0x2018..0x2019, 0x201c..0x201d, 0x2020..0x2022,
  0x2024..0x2026, 0x2030..0x2030, 0x2032..0x2033, 0x2035..0x2035, 0x203b..0x203e,
  0x2074..0x2074, 0x207f..0x207f, 0x2081..0x2084, 0x20ac..0x20ac, 0x2103..0x2103,
  0x2105..0x2105, 0x2109..0x2109, 0x2113..0x2113, 0x2116..0x2116, 0x2121..0x2122,
  0x2126..0x2126, 0x212b..0x212b, 0x2153..0x2154, 0x215b..0x215e, 0x2160..0x216b,
  0x2170..0x2179, 0x2189..0x2189, 0x2190..0x2199, 0x21b8..0x21b9, 0x21d2..0x21d4,
  0x21e7..0x21e7, 0x2200..0x2200, 0x2202..0x2203, 0x2207..0x2208, 0x220b..0x220b,
  0x220f..0x2211, 0x2215..0x2215, 0x221a..0x221a, 0x221d..0x2220, 0x2223..0x2223,
  0x2225..0x2225, 0x2227..0x222c, 0x222e..0x222e, 0x2234..0x2237, 0x223c..0x223d,
  0x2248..0x2248, 0x224c..0x224c, 0x2252..0x2252, 0x2260..0x2261, 0x2264..0x2267,
  0x226a..0x226b, 0x226e..0x226f, 0x2282..0x2283, 0x2286..0x2287, 0x2295..0x2295,
  0x2299..0x2299, 0x22a5..0x22a5, 0x22bf..0x22bf, 0x2312..0x2312, 0x2460..0x254b,
  0x2550..0x2573, 0x2580..0x258f, 0x2592..0x2595, 0x25a0..0x25a1, 0x25a3..0x25a9,
  0x25b2..0x25b3, 0x25b6..0x25b7, 0x25bc..0x25bd, 0x25c0..0x25c1, 0x25c6..0x25c8,
  0x25cb..0x25cb, 0x25ce..0x25d1, 0x25e2..0x25e5, 0x25ef..0x25ef, 0x2605..0x2606,
  0x2609..0x2609, 0x260e..0x260f, 0x261c..0x261c, 0x261e..0x261e, 0x2640..0x2640,
  0x2642..0x2642, 0x2660..0x2661, 0x2663..0x2665, 0x2667..0x266a, 0x266c..0x266d,
  0x266f..0x266f, 0xe000..0xf8ff, 0xfffd..0xfffd
].freeze

Class Method Summary collapse

Class Method Details

.ambiguous?(codepoint) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/shellfie/text_metrics.rb', line 149

def ambiguous?(codepoint)
  return false if codepoint < 0x00a1

  AMBIGUOUS_RANGES.any? { |range| range.cover?(codepoint) }
end

.cell_width(text, ambiguous_width: 1) ⇒ Object 



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# File 'lib/shellfie/text_metrics.rb', line 48

def cell_width(text, ambiguous_width: 1)
  graphemes(text).sum { |grapheme| grapheme_width(grapheme, ambiguous_width: ambiguous_width) }
end

.char_width(char, ambiguous_width: 1) ⇒ Object 



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# File 'lib/shellfie/text_metrics.rb', line 107

def char_width(char, ambiguous_width: 1)
  codepoint = char.ord
  return 0 if combining?(codepoint)
  return 0 if codepoint < 32 || codepoint == 0x7f
  return 2 if wide?(codepoint)
  return ambiguous_width if ambiguous?(codepoint)

  1
end

.combining?(codepoint) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/shellfie/text_metrics.rb', line 126

def combining?(codepoint)
  (0x0300..0x036f).cover?(codepoint) ||
    (0x1ab0..0x1aff).cover?(codepoint) ||
    (0x1dc0..0x1dff).cover?(codepoint) ||
    (0x20d0..0x20ff).cover?(codepoint) ||
    (0xfe00..0xfe0f).cover?(codepoint) ||
    (0xfe20..0xfe2f).cover?(codepoint) ||
    (0xe0100..0xe01ef).cover?(codepoint)
end

.drop_cells(text, cells_to_drop, ambiguous_width: 1) ⇒ Object 



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# File 'lib/shellfie/text_metrics.rb', line 71

def drop_cells(text, cells_to_drop, ambiguous_width: 1)
  used_cells = 0
  graphemes(text).each_with_object(+"") do |char, result|
    width = grapheme_width(char, ambiguous_width: ambiguous_width)
    if used_cells < cells_to_drop
      used_cells += width
      next
    end

    result << char
  end
end

.grapheme_width(grapheme, ambiguous_width: 1) ⇒ Object 



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# File 'lib/shellfie/text_metrics.rb', line 117

def grapheme_width(grapheme, ambiguous_width: 1)
  codepoints = grapheme.codepoints
  return 0 if codepoints.empty? || codepoints.all? { |codepoint| combining?(codepoint) }
  return 2 if grapheme.include?("\u200d") || grapheme.include?("\ufe0f") || grapheme.include?("\u20e3") ||
              grapheme.match?(/[\u{1f1e6}-\u{1f1ff}]{2}/)

  codepoints.map { |codepoint| char_width(codepoint.chr(Encoding::UTF_8), ambiguous_width: ambiguous_width) }.max || 0
end

.graphemes(text) ⇒ Object 



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# File 'lib/shellfie/text_metrics.rb', line 42

def graphemes(text)
  string = text.to_s.dup
  string.force_encoding(Encoding::UTF_8)
  string.scrub.scan(/\X/)
end

.pixel_width(text, font_size, ambiguous_width: 1) ⇒ Object 



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# File 'lib/shellfie/text_metrics.rb', line 52

def pixel_width(text, font_size, ambiguous_width: 1)
  (cell_width(text, ambiguous_width: ambiguous_width) * font_size * 0.6).ceil
end

.split_cells(text, max_cells, ambiguous_width: 1) ⇒ Object 



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# File 'lib/shellfie/text_metrics.rb', line 84

def split_cells(text, max_cells, ambiguous_width: 1)
  return [text.to_s] if max_cells <= 0

  chunks = []
  current = +""
  used_cells = 0

  graphemes(text).each do |char|
    width = grapheme_width(char, ambiguous_width: ambiguous_width)
    if used_cells.positive? && used_cells + width > max_cells
      chunks << current
      current = +""
      used_cells = 0
    end

    current << char
    used_cells += width
  end

  chunks << current unless current.empty?
  chunks
end

.take_cells(text, max_cells, ambiguous_width: 1) ⇒ Object 



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# File 'lib/shellfie/text_metrics.rb', line 56

def take_cells(text, max_cells, ambiguous_width: 1)
  result = +""
  used_cells = 0

  graphemes(text).each do |char|
    width = grapheme_width(char, ambiguous_width: ambiguous_width)
    break if used_cells + width > max_cells

    result << char
    used_cells += width
  end

  result
end

.wide?(codepoint) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/shellfie/text_metrics.rb', line 136

def wide?(codepoint)
  (0x1100..0x115f).cover?(codepoint) ||
    (0x2329..0x232a).cover?(codepoint) ||
    (0x2e80..0xa4cf).cover?(codepoint) ||
    (0xac00..0xd7a3).cover?(codepoint) ||
    (0xf900..0xfaff).cover?(codepoint) ||
    (0xfe10..0xfe19).cover?(codepoint) ||
    (0xfe30..0xfe6f).cover?(codepoint) ||
    (0xff00..0xff60).cover?(codepoint) ||
    (0xffe0..0xffe6).cover?(codepoint) ||
    (0x1f300..0x1faff).cover?(codepoint)
end