from __future__ import annotations from rich.console import RenderableType from textual._easing import EASING from textual.app import App, ComposeResult from textual.cli.previews.borders import TEXT from textual.containers import Container, Horizontal, Vertical from textual.reactive import Reactive from textual.scrollbar import ScrollBarRender from textual.widget import Widget from textual.widgets import Button, Footer, Static, Input VIRTUAL_SIZE = 100 WINDOW_SIZE = 10 START_POSITION = 0.0 END_POSITION = float(VIRTUAL_SIZE - WINDOW_SIZE) class EasingButtons(Widget): def compose(self) -> ComposeResult: for easing in sorted(EASING, reverse=True): yield Button(easing, id=easing) class Bar(Widget): position = Reactive.init(START_POSITION) animation_running = Reactive(False) DEFAULT_CSS = """ Bar { background: $surface; color: $error; } Bar.-active { background: $surface; color: $success; } """ def watch_animation_running(self, running: bool) -> None: self.set_class(running, "-active") def render(self) -> RenderableType: return ScrollBarRender( virtual_size=VIRTUAL_SIZE, window_size=WINDOW_SIZE, position=self.position, style=self.rich_style, ) class EasingApp(App): position = Reactive.init(START_POSITION) duration = Reactive.var(1.0) def on_load(self): self.bind( "ctrl+p", "focus('duration-input')", description="Focus: Duration Input" ) self.bind("ctrl+b", "toggle_dark", description="Toggle Dark") def compose(self) -> ComposeResult: self.animated_bar = Bar() self.animated_bar.position = START_POSITION duration_input = Input("1.0", placeholder="Duration", id="duration-input") self.opacity_widget = Static( f"[b]Welcome to Textual![/]\n\n{TEXT}", id="opacity-widget" ) yield EasingButtons() yield Vertical( Horizontal( Static("Animation Duration:", id="label"), duration_input, id="inputs" ), Horizontal( self.animated_bar, Container(self.opacity_widget, id="other"), ), Footer(), ) def on_button_pressed(self, event: Button.Pressed) -> None: self.animated_bar.animation_running = True def _animation_complete(): self.animated_bar.animation_running = False target_position = ( END_POSITION if self.position == START_POSITION else START_POSITION ) self.animate( "position", value=target_position, final_value=target_position, duration=self.duration, easing=event.button.id, on_complete=_animation_complete, ) def watch_position(self, value: int): self.animated_bar.position = value self.opacity_widget.styles.opacity = 1 - value / END_POSITION def on_input_changed(self, event: Input.Changed): if event.sender.id == "duration-input": new_duration = _try_float(event.value) if new_duration is not None: self.duration = new_duration def action_toggle_dark(self): self.dark = not self.dark def _try_float(string: str) -> float | None: try: return float(string) except ValueError: return None app = EasingApp(css_path="easing.css") if __name__ == "__main__": app.run()