Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/wcwidth/text_sizing.py: 45%

1r""" 

2`kitty text sizing protocol`_ (OSC 66) parsing and measurement. 

3 

4The kitty text sizing protocol allows terminal apps to explicitly tell 

5terminals how many cells text occupies, using the escape sequence:: 

6 

7 ESC ] 66 ; metadata ; text BEL/ST 

8 

9Metadata is colon-separated ``key=value`` pairs: 

10 

11- ``s``: scale 

12- ``w``: width in cells 

13- ``n``: fractional numerator 

14- ``d``: fractional denominator 

15- ``v``: vertical alignment 

16- ``h``: horizontal alignment 

17 

18Parsing is pretty straight-forward: 

19 

20- When ``w > 0``, return ``s * w``. 

21- Otherwise ``w == 0``, ``s * wcswidth(inner_text_width)`` cells. 

22 

23Numerator, denominator, and alignment codes and values are parsed but otherwise ignored 

24and have no effect on measurements made in this library. 

25 

26.. _`kitty text sizing protocol`: https://sw.kovidgoyal.net/kitty/text-sizing-protocol/ 

27 

28.. versionadded:: 0.7.0 

29""" 

30 

31from __future__ import annotations 

32 

33# std imports 

34import re 

35 

36import typing 

37 

38# local 

39from ._wcswidth import wcswidth 

40 

41 

42class _FieldMeta(typing.NamedTuple): 

43 name: str 

44 low: int 

45 high: int 

46 default: int 

47 

48 

49TEXT_FIELD_MAPPING: dict[str, _FieldMeta] = { 

50 's': _FieldMeta(name='scale', low=1, high=7, default=1), 

51 'w': _FieldMeta(name='width', low=0, high=7, default=0), 

52 'n': _FieldMeta(name='numerator', low=0, high=15, default=0), 

53 'd': _FieldMeta(name='denominator', low=0, high=15, default=0), 

54 'v': _FieldMeta(name='vertical_align', low=0, high=2, default=0), 

55 'h': _FieldMeta(name='horizontal_align', low=0, high=2, default=0)} 

56 

57 

58class TextSizingParams(typing.NamedTuple): 

59 """ 

60 Parsed parameters from a text sizing escape sequence (OSC 66). 

61 

62 :param scale: Scale factor (1-7). Text occupies ``scale`` rows tall and ``scale * width`` 

63 columns wide. 

64 :param width: Width in cells (0-7). When 0, width is auto-calculated from the inner text. 

65 :param numerator: Fractional scaling numerator (0-15). 

66 :param denominator: Fractional scaling denominator (0-15). 

67 :param vertical_align: Vertical alignment (0=top, 1=bottom, 2=center). 

68 :param horizontal_align: Horizontal alignment (0=left, 1=right, 2=center). 

69 """ 

70 

71 scale: int = 1 

72 width: int = 0 

73 numerator: int = 0 

74 denominator: int = 0 

75 vertical_align: int = 0 

76 horizontal_align: int = 0 

77 

78 def __repr__(self) -> str: 

79 """ 

80 Return a compact representation including only non-default fields. 

81 

82 This avoids verbose output when most fields are defaults. 

83 """ 

84 # modified to show values only when non-default 

85 repr_fmt = ', '.join(f'{field.name}={getattr(self, field.name)}' 

86 for field in TEXT_FIELD_MAPPING.values() 

87 if getattr(self, field.name) != field.default) 

88 return f'{self.__class__.__name__}({repr_fmt})' 

89 

90 def make_sequence(self) -> str: 

91 """Build and return sub-part of an OSC 66 sequence.""" 

92 parts = [] 

93 # build string for all known parameters of non-default values 

94 for field_key, field in TEXT_FIELD_MAPPING.items(): 

95 if (val := getattr(self, field.name)) != field.default: 

96 parts.append(f'{field_key}={val}') 

97 return ':'.join(parts) 

98 

99 @classmethod 

100 def from_params(cls, raw: str, control_codes: str = 'parse') -> TextSizingParams: 

101 """ 

102 Parse colon-separated ``key=value`` metadata string. 

103 

104 :param raw: Metadata string, e.g. ``'s=2:w=3'``. 

105 :param control_codes: 'parse' or 'strict'. 

106 :raises ValueError: If ``control_codes='strict'`` unrecognized text sizing parameters raise 

107 ValueError. 

108 :returns: Parsed parameters with values clamped to valid ranges. 

109 Unknown keys are ignored. Non-integer values use defaults. 

110 

111 Example:: 

112 

113 >>> TextSizingParams.from_params('s=2:w=3') 

114 TextSizingParams(scale=2, width=3, numerator=0, denominator=0, \ 

115 vertical_align=0, horizontal_align=0) 

116 """ 

117 kwargs: typing.Dict[str, int] = {} 

118 if not raw: 

119 return cls() 

120 for part in raw.split(':'): 

121 if '=' not in part: 

122 if control_codes == 'strict': 

123 raise ValueError(f"Expected '=' in text sizing parameter (key=val), " 

124 f"got {part!r} in OSC 66 sequence, {raw!r}") 

125 continue 

126 key, _eq, val = part.partition('=') 

127 field = TEXT_FIELD_MAPPING.get(key) 

128 if field is None: 

129 if control_codes == 'strict': 

130 raise ValueError(f"Unknown text sizing field '{key}' " 

131 f"in OSC 66 sequence, {raw!r}") 

132 # ignore unknown fields unless 'strict' 

133 continue 

134 try: 

135 value = int(val) 

136 except ValueError as exc: 

137 if control_codes == 'strict': 

138 raise ValueError(f"Illegal text sizing value '{val}' " 

139 f"in OSC 66 sequence, {raw!r}: {exc}") from exc 

140 # ignore value, uses default value without warning unless 'strict' 

141 continue 

142 if control_codes == 'strict' and (value > field.high or value < field.low): 

143 raise ValueError(f"Out of bounds text sizing value '{val}' " 

144 f"in OSC 66 sequence, {raw!r}: " 

145 f"allowed range for '{key}' ({field.name}) " 

146 f"is {field.low} to {field.high}") 

147 kwargs[field.name] = max(field.low, min(field.high, value)) 

148 return cls(**kwargs) 

149 

150 

151class TextSizing(typing.NamedTuple): 

152 """Basic horizontal width measurement for kitty text sizing protocol.""" 

153 

154 params: TextSizingParams 

155 text: str 

156 terminator: str 

157 

158 @classmethod 

159 def from_match(cls, match: re.Match[str], control_codes: str = 'parse') -> TextSizing: 

160 r""" 

161 Parse using matching OSC 66 Sequence. 

162 

163 :param match: match object from :attr:`wcwidth.escape_sequences.TEXT_SIZING_PATTERN`. 

164 :param control_codes: 'parse' or 'strict', same meaning as delegated by 

165 :func:`wcwidth.width`. 

166 :raises ValueError: When ``control_codes='strict'`` for unrecognized, invalid, or out of 

167 bounds text sizing parameters. 

168 :returns: TextSizing object from parsed sequence 

169 

170 Example:: 

171 

172 from wcwidth.escape_sequences import TEXT_SIZING_PATTERN 

173 >>> TextSizing.from_match(TEXT_SIZING_PATTERN.match('\x1b]66;w=2;XY\x07')) 

174 TextSizing(params=TextSizingParams(scale=1, width=2, numerator=0, denominator=0, \ 

175 vertical_align=0, horizontal_align=0), text='XY', terminator='\x07') 

176 """ 

177 return cls(params=TextSizingParams.from_params(match.group(1), control_codes=control_codes), 

178 text=match.group(2), 

179 terminator=match.group(3)) 

180 

181 def display_width(self, ambiguous_width: int = 1) -> int: 

182 """ 

183 Calculate the display width of a text sizing sequence. 

184 

185 :param ambiguous_width: Width for East Asian Ambiguous characters. 

186 :returns: Display width in terminal cells. When ``width > 0``, returns 

187 ``params.scale * params.width``. When ``width == 0``, returns 

188 ``params.scale * measured_inner_width``. 

189 

190 .. note: Fractional scaling (numerator/denominator) does not affect the 

191 cell count, it adjusts only the font size within the cells allocated by 'w'. 

192 """ 

193 if self.params.width > 0: 

194 return self.params.scale * self.params.width 

195 w = wcswidth(self.text, ambiguous_width=ambiguous_width) 

196 return self.params.scale * max(0, w) 

197 

198 def make_sequence(self) -> str: 

199 """Build and return complete OSC 66 Terminal Sequence.""" 

200 return f'\x1b]66;{self.params.make_sequence()};{self.text}{self.terminator}'