Files
textual/src/textual/css/_style_properties.py
Rodrigo Girão Serrão 2b9cd81ca5 Cleanup and new test.
2023-01-17 10:29:19 +00:00

1026 lines
35 KiB
Python

"""
Style properties are descriptors which allow the ``Styles`` object to accept different types when
setting attributes. This gives the developer more freedom in how to express style information.
Descriptors also play nicely with Mypy, which is aware that attributes can have different types
when setting and getting.
"""
from __future__ import annotations
from operator import attrgetter
from typing import TYPE_CHECKING, Generic, Iterable, NamedTuple, TypeVar, cast
import rich.errors
import rich.repr
from rich.style import Style
from .._border import normalize_border_value
from ..color import Color, ColorParseError
from ..geometry import Spacing, SpacingDimensions, clamp
from ._error_tools import friendly_list
from ._help_text import (
border_property_help_text,
color_property_help_text,
fractional_property_help_text,
layout_property_help_text,
offset_property_help_text,
scalar_help_text,
spacing_wrong_number_of_values_help_text,
string_enum_help_text,
style_flags_property_help_text,
)
from .constants import NULL_SPACING, VALID_STYLE_FLAGS
from .errors import StyleTypeError, StyleValueError
from .scalar import (
NULL_SCALAR,
UNIT_SYMBOL,
Scalar,
ScalarOffset,
ScalarParseError,
Unit,
get_symbols,
percentage_string_to_float,
)
from .transition import Transition
if TYPE_CHECKING:
from .._layout import Layout
from .styles import Styles, StylesBase
from .types import AlignHorizontal, AlignVertical, DockEdge, EdgeType
BorderDefinition = (
"Sequence[tuple[EdgeType, str | Color] | None] | tuple[EdgeType, str | Color]"
)
PropertyGetType = TypeVar("PropertyGetType")
PropertySetType = TypeVar("PropertySetType")
class GenericProperty(Generic[PropertyGetType, PropertySetType]):
def __init__(self, default: PropertyGetType, layout: bool = False) -> None:
self.default = default
self.layout = layout
def validate_value(self, value: object) -> PropertyGetType:
"""Validate the setter value
Args:
value (object): The value being set.
Returns:
PropertyType: The value to be set.
"""
# Raise StyleValueError here
return cast(PropertyGetType, value)
def __set_name__(self, owner: Styles, name: str) -> None:
self.name = name
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> PropertyGetType:
return cast(PropertyGetType, obj.get_rule(self.name, self.default))
def __set__(self, obj: StylesBase, value: PropertySetType | None) -> None:
_rich_traceback_omit = True
if value is None:
obj.clear_rule(self.name)
obj.refresh(layout=self.layout)
return
new_value = self.validate_value(value)
if obj.set_rule(self.name, new_value):
obj.refresh(layout=self.layout)
class IntegerProperty(GenericProperty[int, int]):
def validate_value(self, value: object) -> int:
if isinstance(value, (int, float)):
return int(value)
else:
raise StyleValueError(f"Expected a number here, got f{value}")
class BooleanProperty(GenericProperty[bool, bool]):
"""A property that requires a True or False value."""
def validate_value(self, value: object) -> bool:
return bool(value)
class ScalarProperty:
"""Descriptor for getting and setting scalar properties. Scalars are numeric values with a unit, e.g. "50vh"."""
def __init__(
self,
units: set[Unit] | None = None,
percent_unit: Unit = Unit.WIDTH,
allow_auto: bool = True,
) -> None:
self.units: set[Unit] = units or {*UNIT_SYMBOL}
self.percent_unit = percent_unit
self.allow_auto = allow_auto
super().__init__()
def __set_name__(self, owner: Styles, name: str) -> None:
self.name = name
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> Scalar | None:
"""Get the scalar property
Args:
obj (Styles): The ``Styles`` object
objtype (type[Styles]): The ``Styles`` class
Returns:
The Scalar object or ``None`` if it's not set.
"""
return obj.get_rule(self.name)
def __set__(
self, obj: StylesBase, value: float | int | Scalar | str | None
) -> None:
"""Set the scalar property
Args:
obj (Styles): The ``Styles`` object.
value (float | int | Scalar | str | None): The value to set the scalar property to.
You can directly pass a float or int value, which will be interpreted with
a default unit of Cells. You may also provide a string such as ``"50%"``,
as you might do when writing CSS. If a string with no units is supplied,
Cells will be used as the unit. Alternatively, you can directly supply
a ``Scalar`` object.
Raises:
StyleValueError: If the value is of an invalid type, uses an invalid unit, or
cannot be parsed for any other reason.
"""
_rich_traceback_omit = True
if value is None:
obj.clear_rule(self.name)
obj.refresh(layout=True)
return
if isinstance(value, (int, float)):
new_value = Scalar(float(value), Unit.CELLS, Unit.WIDTH)
elif isinstance(value, Scalar):
new_value = value
elif isinstance(value, str):
try:
new_value = Scalar.parse(value)
except ScalarParseError:
raise StyleValueError(
"unable to parse scalar from {value!r}",
help_text=scalar_help_text(
property_name=self.name, context="inline"
),
)
else:
raise StyleValueError("expected float, int, Scalar, or None")
if (
new_value is not None
and new_value.unit == Unit.AUTO
and not self.allow_auto
):
raise StyleValueError("'auto' not allowed here")
if new_value is not None and new_value.unit != Unit.AUTO:
if new_value.unit not in self.units:
raise StyleValueError(
f"{self.name} units must be one of {friendly_list(get_symbols(self.units))}"
)
if new_value.is_percent:
new_value = Scalar(
float(new_value.value), self.percent_unit, Unit.WIDTH
)
if obj.set_rule(self.name, new_value):
obj.refresh(layout=True)
class ScalarListProperty:
def __set_name__(self, owner: Styles, name: str) -> None:
self.name = name
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> tuple[Scalar, ...] | None:
return obj.get_rule(self.name)
def __set__(
self, obj: StylesBase, value: str | Iterable[str | float] | None
) -> None:
if value is None:
obj.clear_rule(self.name)
obj.refresh(layout=True)
return
parse_values: Iterable[str | float]
if isinstance(value, str):
parse_values = value.split()
else:
parse_values = value
scalars = []
for parse_value in parse_values:
if isinstance(parse_value, (int, float)):
scalars.append(Scalar.from_number(parse_value))
else:
scalars.append(
Scalar.parse(parse_value)
if isinstance(parse_value, str)
else parse_value
)
if obj.set_rule(self.name, tuple(scalars)):
obj.refresh(layout=True)
class BoxProperty:
"""Descriptor for getting and setting outlines and borders along a single edge.
For example "border-right", "outline-bottom", etc.
"""
def __init__(self, default_color: Color) -> None:
self._default_color = default_color
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
_type, edge = name.split("_")
self._type = _type
self.edge = edge
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> tuple[EdgeType, Color]:
"""Get the box property
Args:
obj (Styles): The ``Styles`` object
objtype (type[Styles]): The ``Styles`` class
Returns:
A ``tuple[EdgeType, Style]`` containing the string type of the box and
it's style. Example types are "rounded", "solid", and "dashed".
"""
return obj.get_rule(self.name) or ("", self._default_color)
def __set__(self, obj: Styles, border: tuple[EdgeType, str | Color] | None):
"""Set the box property
Args:
obj (Styles): The ``Styles`` object.
value (tuple[EdgeType, str | Color | Style], optional): A 2-tuple containing the type of box to use,
e.g. "dashed", and the ``Style`` to be used. You can supply the ``Style`` directly, or pass a
``str`` (e.g. ``"blue on #f0f0f0"`` ) or ``Color`` instead.
Raises:
StyleSyntaxError: If the string supplied for the color has invalid syntax.
"""
_rich_traceback_omit = True
if border is None:
if obj.clear_rule(self.name):
obj.refresh(layout=True)
else:
_type, color = border
if _type in ("none", "hidden"):
_type = ""
new_value = border
if isinstance(color, str):
try:
new_value = (_type, Color.parse(color))
except ColorParseError as error:
raise StyleValueError(
str(error),
help_text=border_property_help_text(
self.name, context="inline"
),
)
elif isinstance(color, Color):
new_value = (_type, color)
current_value: tuple[str, Color] = cast(
"tuple[str, Color]", obj.get_rule(self.name)
)
has_edge = bool(current_value and current_value[0])
new_edge = bool(_type)
if obj.set_rule(self.name, new_value):
obj.refresh(layout=has_edge != new_edge)
@rich.repr.auto
class Edges(NamedTuple):
"""Stores edges for border / outline."""
top: tuple[EdgeType, Color]
right: tuple[EdgeType, Color]
bottom: tuple[EdgeType, Color]
left: tuple[EdgeType, Color]
def __bool__(self) -> bool:
(top, _), (right, _), (bottom, _), (left, _) = self
return bool(top or right or bottom or left)
def __rich_repr__(self) -> rich.repr.Result:
top, right, bottom, left = self
if top[0]:
yield "top", top
if right[0]:
yield "right", right
if bottom[0]:
yield "bottom", bottom
if left[0]:
yield "left", left
@property
def spacing(self) -> Spacing:
"""Get spacing created by borders.
Returns:
tuple[int, int, int, int]: Spacing for top, right, bottom, and left.
"""
(top, _), (right, _), (bottom, _), (left, _) = self
return Spacing(
1 if top else 0,
1 if right else 0,
1 if bottom else 0,
1 if left else 0,
)
class BorderProperty:
"""Descriptor for getting and setting full borders and outlines.
Args:
layout (bool): True if the layout should be refreshed after setting, False otherwise.
"""
def __init__(self, layout: bool) -> None:
self._layout = layout
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
self._properties = (
f"{name}_top",
f"{name}_right",
f"{name}_bottom",
f"{name}_left",
)
self._get_properties = attrgetter(*self._properties)
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> Edges:
"""Get the border
Args:
obj (Styles): The ``Styles`` object
objtype (type[Styles]): The ``Styles`` class
Returns:
An ``Edges`` object describing the type and style of each edge.
"""
return Edges(*self._get_properties(obj))
def __set__(
self,
obj: StylesBase,
border: BorderDefinition | None,
) -> None:
"""Set the border
Args:
obj (Styles): The ``Styles`` object.
border (Sequence[tuple[EdgeType, str | Color | Style] | None] | tuple[EdgeType, str | Color | Style] | None):
A ``tuple[EdgeType, str | Color | Style]`` representing the type of box to use and the ``Style`` to apply
to the box.
Alternatively, you can supply a sequence of these tuples and they will be applied per-edge.
If the sequence is of length 1, all edges will be decorated according to the single element.
If the sequence is length 2, the first ``tuple`` will be applied to the top and bottom edges.
If the sequence is length 4, the tuples will be applied to the edges in the order: top, right, bottom, left.
Raises:
StyleValueError: When the supplied ``tuple`` is not of valid length (1, 2, or 4).
"""
_rich_traceback_omit = True
top, right, bottom, left = self._properties
border_spacing = Edges(*self._get_properties(obj)).spacing
def check_refresh() -> None:
"""Check if an update requires a layout"""
if not self._layout:
obj.refresh()
else:
layout = Edges(*self._get_properties(obj)).spacing != border_spacing
obj.refresh(layout=layout)
if border is None:
clear_rule = obj.clear_rule
clear_rule(top)
clear_rule(right)
clear_rule(bottom)
clear_rule(left)
check_refresh()
return
if isinstance(border, tuple) and len(border) == 2:
_border = normalize_border_value(border)
setattr(obj, top, _border)
setattr(obj, right, _border)
setattr(obj, bottom, _border)
setattr(obj, left, _border)
check_refresh()
return
count = len(border)
if count == 1:
_border = normalize_border_value(border[0])
setattr(obj, top, _border)
setattr(obj, right, _border)
setattr(obj, bottom, _border)
setattr(obj, left, _border)
elif count == 2:
_border1, _border2 = (
normalize_border_value(border[0]),
normalize_border_value(border[1]),
)
setattr(obj, top, _border1)
setattr(obj, bottom, _border1)
setattr(obj, right, _border2)
setattr(obj, left, _border2)
elif count == 4:
_border1, _border2, _border3, _border4 = (
normalize_border_value(border[0]),
normalize_border_value(border[1]),
normalize_border_value(border[2]),
normalize_border_value(border[3]),
)
setattr(obj, top, _border1)
setattr(obj, right, _border2)
setattr(obj, bottom, _border3)
setattr(obj, left, _border4)
else:
raise StyleValueError(
"expected 1, 2, or 4 values",
help_text=border_property_help_text(self.name, context="inline"),
)
check_refresh()
class SpacingProperty:
"""Descriptor for getting and setting spacing properties (e.g. padding and margin)."""
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> Spacing:
"""Get the Spacing
Args:
obj (Styles): The ``Styles`` object
objtype (type[Styles]): The ``Styles`` class
Returns:
Spacing: The Spacing. If unset, returns the null spacing ``(0, 0, 0, 0)``.
"""
return obj.get_rule(self.name, NULL_SPACING)
def __set__(self, obj: StylesBase, spacing: SpacingDimensions | None):
"""Set the Spacing
Args:
obj (Styles): The ``Styles`` object.
style (Style | str, optional): You can supply the ``Style`` directly, or a
string (e.g. ``"blue on #f0f0f0"``).
Raises:
ValueError: When the value is malformed, e.g. a ``tuple`` with a length that is
not 1, 2, or 4.
"""
_rich_traceback_omit = True
if spacing is None:
if obj.clear_rule(self.name):
obj.refresh(layout=True)
else:
try:
unpacked_spacing = Spacing.unpack(spacing)
except ValueError as error:
raise StyleValueError(
str(error),
help_text=spacing_wrong_number_of_values_help_text(
property_name=self.name,
num_values_supplied=len(spacing),
context="inline",
),
)
if obj.set_rule(self.name, unpacked_spacing):
obj.refresh(layout=True)
class DockProperty:
"""Descriptor for getting and setting the dock property. The dock property
allows you to specify which edge you want to fix a Widget to.
"""
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> DockEdge:
"""Get the Dock property
Args:
obj (Styles): The ``Styles`` object.
objtype (type[Styles]): The ``Styles`` class.
Returns:
str: The dock name as a string, or "" if the rule is not set.
"""
return cast(DockEdge, obj.get_rule("dock", ""))
def __set__(self, obj: Styles, dock_name: str | None):
"""Set the Dock property
Args:
obj (Styles): The ``Styles`` object
dock_name (str | None): The name of the dock to attach this widget to
"""
_rich_traceback_omit = True
if obj.set_rule("dock", dock_name):
obj.refresh(layout=True)
class LayoutProperty:
"""Descriptor for getting and setting layout."""
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> Layout | None:
"""
Args:
obj (Styles): The Styles object
objtype (type[Styles]): The Styles class
Returns:
The ``Layout`` object.
"""
return obj.get_rule(self.name)
def __set__(self, obj: StylesBase, layout: str | Layout | None):
"""
Args:
obj (Styles): The Styles object.
layout (str | Layout): The layout to use. You can supply the name of the layout
or a ``Layout`` object.
"""
from ..layouts.factory import (
Layout, # Prevents circular import
MissingLayout,
get_layout,
)
_rich_traceback_omit = True
if layout is None:
if obj.clear_rule("layout"):
obj.refresh(layout=True)
elif isinstance(layout, Layout):
if obj.set_rule("layout", layout):
obj.refresh(layout=True)
else:
try:
layout_object = get_layout(layout)
except MissingLayout as error:
raise StyleValueError(
str(error),
help_text=layout_property_help_text(self.name, context="inline"),
)
if obj.set_rule("layout", layout_object):
obj.refresh(layout=True)
class OffsetProperty:
"""Descriptor for getting and setting the offset property.
Offset consists of two values, x and y, that a widget's position
will be adjusted by before it is rendered.
"""
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> ScalarOffset:
"""Get the offset
Args:
obj (Styles): The ``Styles`` object.
objtype (type[Styles]): The ``Styles`` class.
Returns:
ScalarOffset: The ``ScalarOffset`` indicating the adjustment that
will be made to widget position prior to it being rendered.
"""
return obj.get_rule(self.name, NULL_SCALAR)
def __set__(
self, obj: StylesBase, offset: tuple[int | str, int | str] | ScalarOffset | None
):
"""Set the offset
Args:
obj: The ``Styles`` class
offset: A ScalarOffset object, or a 2-tuple of the form ``(x, y)`` indicating
the x and y offsets. When the ``tuple`` form is used, x and y can be specified
as either ``int`` or ``str``. The string format allows you to also specify
any valid scalar unit e.g. ``("0.5vw", "0.5vh")``.
Raises:
ScalarParseError: If any of the string values supplied in the 2-tuple cannot
be parsed into a Scalar. For example, if you specify a non-existent unit.
"""
_rich_traceback_omit = True
if offset is None:
if obj.clear_rule(self.name):
obj.refresh(layout=True)
elif isinstance(offset, ScalarOffset):
if obj.set_rule(self.name, offset):
obj.refresh(layout=True)
else:
x, y = offset
try:
scalar_x = (
Scalar.parse(x, Unit.WIDTH)
if isinstance(x, str)
else Scalar(float(x), Unit.CELLS, Unit.WIDTH)
)
scalar_y = (
Scalar.parse(y, Unit.HEIGHT)
if isinstance(y, str)
else Scalar(float(y), Unit.CELLS, Unit.HEIGHT)
)
except ScalarParseError as error:
raise StyleValueError(
str(error), help_text=offset_property_help_text(context="inline")
)
_offset = ScalarOffset(scalar_x, scalar_y)
if obj.set_rule(self.name, _offset):
obj.refresh(layout=True)
class StringEnumProperty:
"""Descriptor for getting and setting string properties and ensuring that the set
value belongs in the set of valid values.
"""
def __init__(self, valid_values: set[str], default: str, layout=False) -> None:
self._valid_values = valid_values
self._default = default
self._layout = layout
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
def __get__(self, obj: StylesBase, objtype: type[StylesBase] | None = None) -> str:
"""Get the string property, or the default value if it's not set
Args:
obj (Styles): The ``Styles`` object.
objtype (type[Styles]): The ``Styles`` class.
Returns:
str: The string property value
"""
return obj.get_rule(self.name, self._default)
def __set__(self, obj: StylesBase, value: str | None = None):
"""Set the string property and ensure it is in the set of allowed values.
Args:
obj (Styles): The ``Styles`` object
value (str, optional): The string value to set the property to.
Raises:
StyleValueError: If the value is not in the set of valid values.
"""
_rich_traceback_omit = True
if value is None:
if obj.clear_rule(self.name):
obj.refresh(layout=self._layout)
else:
if value not in self._valid_values:
raise StyleValueError(
f"{self.name} must be one of {friendly_list(self._valid_values)} (received {value!r})",
help_text=string_enum_help_text(
self.name,
valid_values=list(self._valid_values),
context="inline",
),
)
if obj.set_rule(self.name, value):
obj.refresh(layout=self._layout)
class NameProperty:
"""Descriptor for getting and setting name properties."""
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
def __get__(self, obj: StylesBase, objtype: type[StylesBase] | None) -> str:
"""Get the name property
Args:
obj (Styles): The ``Styles`` object.
objtype (type[Styles]): The ``Styles`` class.
Returns:
str: The name
"""
return obj.get_rule(self.name, "")
def __set__(self, obj: StylesBase, name: str | None):
"""Set the name property
Args:
obj: The ``Styles`` object
name: The name to set the property to
Raises:
StyleTypeError: If the value is not a ``str``.
"""
_rich_traceback_omit = True
if name is None:
if obj.clear_rule(self.name):
obj.refresh(layout=True)
else:
if not isinstance(name, str):
raise StyleTypeError(f"{self.name} must be a str")
if obj.set_rule(self.name, name):
obj.refresh(layout=True)
class NameListProperty:
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> tuple[str, ...]:
return cast("tuple[str, ...]", obj.get_rule(self.name, ()))
def __set__(self, obj: StylesBase, names: str | tuple[str] | None = None):
_rich_traceback_omit = True
if names is None:
if obj.clear_rule(self.name):
obj.refresh(layout=True)
elif isinstance(names, str):
if obj.set_rule(
self.name, tuple(name.strip().lower() for name in names.split(" "))
):
obj.refresh(layout=True)
elif isinstance(names, tuple):
if obj.set_rule(self.name, names):
obj.refresh(layout=True)
class ColorProperty:
"""Descriptor for getting and setting color properties."""
def __init__(self, default_color: Color | str) -> None:
self._default_color = Color.parse(default_color)
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> Color:
"""Get a ``Color``.
Args:
obj (Styles): The ``Styles`` object.
objtype (type[Styles]): The ``Styles`` class.
Returns:
Color: The Color
"""
return cast(Color, obj.get_rule(self.name, self._default_color))
def __set__(self, obj: StylesBase, color: Color | str | None):
"""Set the Color
Args:
obj (Styles): The ``Styles`` object
color (Color | str | None): The color to set. Pass a ``Color`` instance directly,
or pass a ``str`` which will be parsed into a color (e.g. ``"red""``, ``"rgb(20, 50, 80)"``,
``"#f4e32d"``).
Raises:
ColorParseError: When the color string is invalid.
"""
_rich_traceback_omit = True
if color is None:
if obj.clear_rule(self.name):
obj.refresh(children=True)
elif isinstance(color, Color):
if obj.set_rule(self.name, color):
obj.refresh(children=True)
elif isinstance(color, str):
alpha = 1.0
parsed_color = Color(255, 255, 255)
for token in color.split():
if token.endswith("%"):
try:
alpha = percentage_string_to_float(token)
except ValueError:
raise StyleValueError(f"invalid percentage value '{token}'")
continue
try:
parsed_color = Color.parse(token)
except ColorParseError as error:
raise StyleValueError(
f"Invalid color value '{token}'",
help_text=color_property_help_text(
self.name, context="inline", error=error
),
)
parsed_color = parsed_color.with_alpha(alpha)
if obj.set_rule(self.name, parsed_color):
obj.refresh(children=True)
else:
raise StyleValueError(f"Invalid color value {color}")
class StyleFlagsProperty:
"""Descriptor for getting and set style flag properties (e.g. ``bold italic underline``)."""
def __set_name__(self, owner: Styles, name: str) -> None:
self.name = name
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> Style:
"""Get the ``Style``
Args:
obj (Styles): The ``Styles`` object.
objtype (type[Styles]): The ``Styles`` class.
Returns:
Style: The ``Style`` object
"""
return obj.get_rule(self.name, Style.null())
def __set__(self, obj: StylesBase, style_flags: Style | str | None):
"""Set the style using a style flag string
Args:
obj (Styles): The ``Styles`` object.
style_flags (str, optional): The style flags to set as a string. For example,
``"bold italic"``.
Raises:
StyleValueError: If the value is an invalid style flag
"""
_rich_traceback_omit = True
if style_flags is None:
if obj.clear_rule(self.name):
obj.refresh()
elif isinstance(style_flags, Style):
if obj.set_rule(self.name, style_flags):
obj.refresh()
else:
words = [word.strip() for word in style_flags.split(" ")]
valid_word = VALID_STYLE_FLAGS.__contains__
for word in words:
if not valid_word(word):
raise StyleValueError(
f"unknown word {word!r} in style flags",
help_text=style_flags_property_help_text(
self.name, word, context="inline"
),
)
try:
style = Style.parse(style_flags)
except rich.errors.StyleSyntaxError as error:
if "none" in words and len(words) > 1:
raise StyleValueError(
"cannot mix 'none' with other style flags",
help_text=style_flags_property_help_text(
self.name, " ".join(words), context="inline"
),
) from None
raise error from None
if obj.set_rule(self.name, style):
obj.refresh()
class TransitionsProperty:
"""Descriptor for getting transitions properties"""
def __get__(
self, obj: StylesBase, objtype: type[StylesBase] | None = None
) -> dict[str, Transition]:
"""Get a mapping of properties to the transitions applied to them.
Args:
obj (Styles): The ``Styles`` object.
objtype (type[Styles]): The ``Styles`` class.
Returns:
dict[str, Transition]: A ``dict`` mapping property names to the ``Transition`` applied to them.
e.g. ``{"offset": Transition(...), ...}``. If no transitions have been set, an empty ``dict``
is returned.
"""
return obj.get_rule("transitions", {})
def __set__(self, obj: Styles, transitions: dict[str, Transition] | None) -> None:
_rich_traceback_omit = True
if transitions is None:
obj.clear_rule("transitions")
else:
obj.set_rule("transitions", transitions.copy())
class FractionalProperty:
"""Property that can be set either as a float (e.g. 0.1) or a
string percentage (e.g. '10%'). Values will be clamped to the range (0, 1).
"""
def __init__(self, default: float = 1.0):
self.default = default
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.name = name
def __get__(self, obj: StylesBase, type: type[StylesBase]) -> float:
"""Get the property value as a float between 0 and 1
Args:
obj (Styles): The ``Styles`` object.
objtype (type[Styles]): The ``Styles`` class.
Returns:
float: The value of the property (in the range (0, 1))
"""
return cast(float, obj.get_rule(self.name, self.default))
def __set__(self, obj: StylesBase, value: float | str | None) -> None:
"""Set the property value, clamping it between 0 and 1.
Args:
obj (Styles): The Styles object.
value (float|str|None): The value to set as a float between 0 and 1, or
as a percentage string such as '10%'.
"""
_rich_traceback_omit = True
name = self.name
if value is None:
if obj.clear_rule(name):
obj.refresh()
return
if isinstance(value, float):
float_value = value
elif isinstance(value, str) and value.endswith("%"):
float_value = float(Scalar.parse(value).value) / 100
else:
raise StyleValueError(
f"{self.name} must be a str (e.g. '10%') or a float (e.g. 0.1)",
help_text=fractional_property_help_text(name, context="inline"),
)
if obj.set_rule(name, clamp(float_value, 0, 1)):
obj.refresh()
class AlignProperty:
"""Combines the horizontal and vertical alignment properties in to a single property."""
def __set_name__(self, owner: StylesBase, name: str) -> None:
self.horizontal = f"{name}_horizontal"
self.vertical = f"{name}_vertical"
def __get__(
self, obj: StylesBase, type: type[StylesBase]
) -> tuple[AlignHorizontal, AlignVertical]:
horizontal = getattr(obj, self.horizontal)
vertical = getattr(obj, self.vertical)
return (horizontal, vertical)
def __set__(
self, obj: StylesBase, value: tuple[AlignHorizontal, AlignVertical]
) -> None:
horizontal, vertical = value
setattr(obj, self.horizontal, horizontal)
setattr(obj, self.vertical, vertical)