Module: Shellfie::TextMetrics

Defined in:
lib/shellfie/text_metrics.rb

Class Method Summary collapse

Class Method Details

.cell_width(text) ⇒ Object 



7
8
9
 
# File 'lib/shellfie/text_metrics.rb', line 7

def cell_width(text)
  text.to_s.each_char.sum { |char| char_width(char) }
end

.char_width(char) ⇒ Object 



66
67
68
69
70
71
72
73
 
# File 'lib/shellfie/text_metrics.rb', line 66

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

  1
end

.combining?(codepoint) ⇒ Boolean

Returns:

  • (Boolean) 


75
76
77
78
79
80
81
 
# File 'lib/shellfie/text_metrics.rb', line 75

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

.drop_cells(text, cells_to_drop) ⇒ Object 



30
31
32
33
34
35
36
37
38
39
40
41
 
# File 'lib/shellfie/text_metrics.rb', line 30

def drop_cells(text, cells_to_drop)
  used_cells = 0
  text.to_s.each_char.with_object(+"") do |char, result|
    width = char_width(char)
    if used_cells < cells_to_drop
      used_cells += width
      next
    end

    result << char
  end
end

.pixel_width(text, font_size) ⇒ Object 



11
12
13
 
# File 'lib/shellfie/text_metrics.rb', line 11

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

.split_cells(text, max_cells) ⇒ Object 



43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
 
# File 'lib/shellfie/text_metrics.rb', line 43

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

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

  text.to_s.each_char do |char|
    width = char_width(char)
    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) ⇒ Object 



15
16
17
18
19
20
21
22
23
24
25
26
27
28
 
# File 'lib/shellfie/text_metrics.rb', line 15

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

  text.to_s.each_char do |char|
    width = char_width(char)
    break if used_cells + width > max_cells

    result << char
    used_cells += width
  end

  result
end

.wide?(codepoint) ⇒ Boolean

Returns:

  • (Boolean) 


83
84
85
86
87
88
89
90
91
92
93
94
 
# File 'lib/shellfie/text_metrics.rb', line 83

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