Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/graphviz/parameters/engines.py: 79%

1"""Rendering engine parameter handling.""" 

2 

3from collections.abc import Set 

4from typing import Final 

5 

6from . import base 

7 

8__all__ = ['ENGINES', 'verify_engine', 'Engine'] 

9 

10ENGINES: Final[Set[str]] = {'dot', # https://www.graphviz.org/pdf/dot.1.pdf 

11 'neato', 

12 'twopi', 

13 'circo', 

14 'fdp', 

15 'sfdp', 

16 'patchwork', 

17 'osage'} 

18 

19DEFAULT_ENGINE: Final = 'dot' 

20 

21REQUIRED: Final = True 

22 

23 

24def verify_engine(engine: str, *, required: bool = REQUIRED) -> None: 

25 if engine is None: 

26 if required: 

27 raise ValueError('missing engine') 

28 elif engine.lower() not in ENGINES: 

29 raise ValueError(f'unknown engine: {engine!r}' 

30 f' (must be one of {sorted(ENGINES)})') 

31 

32 

33class Engine(base.ParameterBase): 

34 """Rendering engine parameter with ``'dot''`` default.""" 

35 

36 _engine = DEFAULT_ENGINE 

37 

38 _verify_engine = staticmethod(verify_engine) 

39 

40 def __init__(self, *, engine: str | None = None, **kwargs) -> None: 

41 super().__init__(**kwargs) 

42 

43 if engine is not None: 

44 self.engine = engine 

45 

46 def _copy_kwargs(self, **kwargs): 

47 """Return the kwargs to create a copy of the instance.""" 

48 engine = self._getattr_from_dict('_engine') 

49 if engine is not None: 

50 kwargs['engine'] = engine 

51 return super()._copy_kwargs(**kwargs) 

52 

53 @property 

54 def engine(self) -> str: 

55 """The layout engine used for rendering 

56 (``'dot'``, ``'neato'``, ...).""" 

57 return self._engine 

58 

59 @engine.setter 

60 def engine(self, engine: str) -> None: 

61 engine = engine.lower() 

62 self._verify_engine(engine) 

63 self._engine = engine