Module textual.css.scalar_animation
Expand source code
from __future__ import annotations
from typing import TYPE_CHECKING
from .scalar import ScalarOffset
from .._animator import Animation
from .._animator import EasingFunction
from .._types import CallbackType
from ..geometry import Offset
if TYPE_CHECKING:
from ..widget import Widget
from .styles import Styles
class ScalarAnimation(Animation):
def __init__(
self,
widget: Widget,
styles: Styles,
start_time: float,
attribute: str,
value: ScalarOffset,
duration: float | None,
speed: float | None,
easing: EasingFunction,
on_complete: CallbackType | None = None,
):
assert (
speed is not None or duration is not None
), "One of speed or duration required"
self.widget = widget
self.styles = styles
self.start_time = start_time
self.attribute = attribute
self.final_value = value
self.easing = easing
self.on_complete = on_complete
size = widget.outer_size
viewport = widget.app.size
self.start: Offset = getattr(styles, attribute).resolve(size, viewport)
self.destination: Offset = value.resolve(size, viewport)
if speed is not None:
distance = self.start.get_distance_to(self.destination)
self.duration = distance / speed
else:
assert duration is not None, "Duration expected to be non-None"
self.duration = duration
def __call__(self, time: float) -> bool:
factor = min(1.0, (time - self.start_time) / self.duration)
eased_factor = self.easing(factor)
if eased_factor >= 1:
setattr(self.styles, self.attribute, self.final_value)
return True
if hasattr(self.start, "blend"):
value = self.start.blend(self.destination, eased_factor)
else:
value = self.start + (self.destination - self.start) * eased_factor
current = self.styles._rules.get(self.attribute)
if current != value:
setattr(self.styles, f"{self.attribute}", value)
return False
def __eq__(self, other: object) -> bool:
if isinstance(other, ScalarAnimation):
return (
self.final_value == other.final_value
and self.duration == other.duration
)
return FalseClasses
class ScalarAnimation (widget: Widget, styles: Styles, start_time: float, attribute: str, value: ScalarOffset, duration: float | None, speed: float | None, easing: EasingFunction, on_complete: CallbackType | None = None)-
Helper class that provides a standard way to create an ABC using inheritance.
Expand source code
class ScalarAnimation(Animation): def __init__( self, widget: Widget, styles: Styles, start_time: float, attribute: str, value: ScalarOffset, duration: float | None, speed: float | None, easing: EasingFunction, on_complete: CallbackType | None = None, ): assert ( speed is not None or duration is not None ), "One of speed or duration required" self.widget = widget self.styles = styles self.start_time = start_time self.attribute = attribute self.final_value = value self.easing = easing self.on_complete = on_complete size = widget.outer_size viewport = widget.app.size self.start: Offset = getattr(styles, attribute).resolve(size, viewport) self.destination: Offset = value.resolve(size, viewport) if speed is not None: distance = self.start.get_distance_to(self.destination) self.duration = distance / speed else: assert duration is not None, "Duration expected to be non-None" self.duration = duration def __call__(self, time: float) -> bool: factor = min(1.0, (time - self.start_time) / self.duration) eased_factor = self.easing(factor) if eased_factor >= 1: setattr(self.styles, self.attribute, self.final_value) return True if hasattr(self.start, "blend"): value = self.start.blend(self.destination, eased_factor) else: value = self.start + (self.destination - self.start) * eased_factor current = self.styles._rules.get(self.attribute) if current != value: setattr(self.styles, f"{self.attribute}", value) return False def __eq__(self, other: object) -> bool: if isinstance(other, ScalarAnimation): return ( self.final_value == other.final_value and self.duration == other.duration ) return FalseAncestors
- textual._animator.Animation
- abc.ABC
Class variables
var on_complete : CallbackType | None