Files
2026-07-12 18:56:10 +05:45

264 lines
6.7 KiB
Python

# Author: Yousef EL-Darsh
# License (SPDX): AGPL-3.0-or-later
from functools import cache
from typing import Protocol, cast
from fabric.core.service import Property, Service, Signal
from fabric.utils import GLib, Gtk, clamp
@cache
def lerp(start: float, end: float, progress: float) -> float:
return start + (end - start) * progress
@cache
def steps(n: int, progress: float, start_jump: bool = False) -> float:
if start_jump:
return min(int(progress * n), n - 1) / (n - 1) if n > 1 else 0.0
return min(int(progress * n + 1e-10), n) / n
@cache
def cubic_bezier(
x1: float, y1: float, x2: float, y2: float, progress: float, epsilon=1e-6
) -> float:
# implementation yanked off of the internet, don't blame me about anything.
# Fast-path boundaries to avoid overshoot and unnecessary work
if progress <= 0.0 or progress >= 1.0:
return clamp(progress, 0.0, 1.0)
t_guess = progress
for _ in range(8):
t = t_guess
t_sq = t * t
omt = 1.0 - t
omt_sq = omt * omt
x = 3 * x1 * omt_sq * t + 3 * x2 * omt * t_sq + t * t_sq
dx = 3 * x1 * omt_sq + 6 * (x2 - x1) * omt * t + 3 * (1 - x2) * t_sq
if abs(dx) < epsilon:
break
delta = (x - progress) / dx
t_guess -= delta
t_guess = clamp(t_guess, 0.0, 1.0)
if abs(delta) < epsilon:
break
t = clamp(t_guess, 0.0, 1.0)
t_sq = t * t
omt = 1.0 - t
return 3 * y1 * omt * omt * t + 3 * y2 * omt * t_sq + t * t_sq
def ease_linear(progress: float) -> float:
return cubic_bezier(1, 1, 0, 0, progress)
def ease_in(progress: float) -> float:
return cubic_bezier(0.4, 0, 1, 1, progress)
def ease_out(progress: float) -> float:
return cubic_bezier(0, 0, 0.2, 1, progress)
def ease_in_out(progress: float) -> float:
return cubic_bezier(0.4, 0, 0.2, 1, progress)
class TimingFunctionCallback(Protocol):
def __call__(self, progress: float, *args, **kwargs) -> float: ...
class Animator(Service):
"""
An animator is a simple way for animating a value on
a set timeline based on a given timing function
"""
@Signal
def finished(self) -> None: ...
@Property(TimingFunctionCallback, "read-write")
def timing_function(self) -> TimingFunctionCallback:
return self._timing_function
@timing_function.setter
def timing_function(self, value: TimingFunctionCallback):
self._timing_function = value
return
@Property(float, "read-write")
def duration(self):
return self._duration
@duration.setter
def duration(self, value: float):
if value <= 0.0:
raise ValueError("duration can't be smaller than or equal to 0.0")
self._duration = value
return
@Property(float, "read-write")
def value(self):
return self._value
@value.setter
def value(self, value: float):
self._value = value
return
@Property(float, "read-write")
def max_value(self):
return self._max_value
@max_value.setter
def max_value(self, value: float):
self._max_value = value
return
@Property(float, "read-write")
def min_value(self):
return self._min_value
@min_value.setter
def min_value(self, value: float):
self._min_value = value
return
@Property(bool, "read-write", default_value=False)
def playing(self):
return self._playing
@playing.setter
def playing(self, value: bool): # this setter is intended for internal usage only
self._playing = value
return
@Property(bool, "read-write", default_value=False)
def repeat(self):
return self._repeat
@repeat.setter
def repeat(self, value: bool):
self._repeat = value
return
def __init__(
self,
duration: float = 0.8,
timing_function: TimingFunctionCallback = ease_linear,
value: float = 0.0,
min_value: float = 0.0,
max_value: float = 1.0,
repeat: bool = False,
tick_widget: Gtk.Widget | None = None,
tick_interval: int = 16,
**kwargs,
):
super().__init__(**kwargs)
self._playing = False
self._value = value
self._min_value = 0.0
self._max_value = 1.0
self._repeat = False
self._duration = 0.8
self._timing_function = timing_function
self._tick_widget = tick_widget
self._tick_interval = tick_interval
self.timing_function = timing_function
self.repeat = repeat
self.duration = duration
self.min_value = min_value
self.max_value = max_value
self.value = value
self.playing = False
self._start_time = None
self._tick_handler = None
self._timeline_pos = 0.0
def do_get_time_now(self):
return GLib.get_monotonic_time() / 1_000_000
def do_update_value(self, delta_time: float):
if not self._playing:
return
elapsed_time = delta_time - cast(float, self._start_time)
self._timeline_pos = min(1.0, elapsed_time / self._duration)
self.value = lerp(
self._min_value,
self._max_value,
self._timing_function(progress=self._timeline_pos),
)
if not self._timeline_pos >= 1.0:
return
if not self._repeat:
# all done..
self.value = self._max_value
self.finished()
self.pause()
return
self._start_time = delta_time
self._timeline_pos = 0.0
return
def do_handle_tick(self, *_):
current_time = self.do_get_time_now()
self.do_update_value(current_time)
return True
def do_remove_tick_handlers(self):
if not self._tick_handler:
return
if self._tick_widget:
self._tick_widget.remove_tick_callback(self._tick_handler)
else:
GLib.source_remove(self._tick_handler)
self._tick_handler = None
return
def play(self):
if self._playing:
return
self.playing = True
self._start_time = self.do_get_time_now()
if self._tick_handler:
return
if self._tick_widget:
self._tick_handler = self._tick_widget.add_tick_callback(
self.do_handle_tick
)
return
self._tick_handler = GLib.timeout_add(self._tick_interval, self.do_handle_tick)
return
def pause(self):
self.playing = False
return self.do_remove_tick_handlers()
def stop(self):
if not self._tick_handler:
self._timeline_pos = 0
self.playing = False
return
return self.do_remove_tick_handlers()