Style Module

The style module contains regular expressions and functions for parsing and composing style strings.

Style string definition: https://datatracker.ietf.org/doc/id/draft-slevinski-formal-signwriting-10.html#name-styling-string

sutton_signwriting_core.style.style_parse(style_string)

Parse a style string to a structured dictionary.

Parameters:

style_string (str) – a style string

Returns:

Dictionary with style elements

Return type:

StyleObject

Example

>>> style_parse('-CP10G_blue_D_red,Cyan_')
{'colorize': True, 'padding': 10, 'background': 'blue', 'detail': ['red', 'Cyan']}
sutton_signwriting_core.style.style_compose(style_dict)

Function to compose style string from dictionary.

Parameters:

style_dict (StyleObject) – a dictionary of style elements with keys: - ‘colorize’: Optional[bool] - ‘padding’: Optional[int] - ‘background’: Optional[str] - ‘detail’: Optional[List[str]] - ‘zoom’: Optional[Union[float, str]] - ‘detailsym’: Optional[List[Dict]] (each with ‘index’: int, ‘detail’: List[str]) - ‘classes’: Optional[str] - ‘id’: Optional[str]

Returns:

style string

Return type:

str | None

Example

>>> style_compose({
...     'colorize': True,
...     'padding': 10,
...     'background': 'blue',
...     'detail': ['red', 'Cyan'],
...     'zoom': 1.1,
...     'detailsym': [
...         {'index': 1, 'detail': ['#ff0', 'green']}
...     ]
... })
'-CP10GblueDred,CyanZ1.1-D01#ff0,green_'
sutton_signwriting_core.style.style_rgb_to_hex(rgb, tolerance=0.0)

Function to convert rgb color to hex or “transparent” if below tolerance.

Parameters:

  • rgb (str) – an rgb color

  • tolerance (float) – max alpha for full transparency (default: 0)

Returns:

a hex color or “transparent”

Return type:

str

Examples

>>> style_rgb_to_hex("rgb(255,255,255)")
'ffffff'
>>> style_rgb_to_hex("rgba(255,255,255,0.5)",0.5)
'transparent'
sutton_signwriting_core.style.style_rgba_to_hex(color, background)

Function to merge color with background based on alpha transparency

Parameters:

  • color (str) – an rgba color

  • background (str) – an rgba background color

Returns:

a hex color or “transparent”

Return type:

str

Example

>>> style_rgba_to_hex("rgba(255,255,255,0.5)","rgb(0,0,0)")
'7f7f7f'
sutton_signwriting_core.style.style_merge(style1, style2)

Function to merge style dictionaries.

Parameters:
Returns:

a style dictionary

Return type:

StyleObject

Example

>>> style_merge({'colorize': True}, {'zoom': 2})
{'colorize': True, 'zoom': 2}