SaraTune/Transport.py

"""The play bar at the bottom of both modes: what's playing, previous / play /
next, the seek bar and volume. Each mode adds its own toggles (loop, shuffle,
repeat) through Extras."""

import asyncio
from typing import Awaitable, Callable, Optional

import flet as ft

from Core import FormatTime, Palette
from Player import Player

CoverSize = 52


def CoverImage(Data: Optional[bytes], Size: int, Radius: int = 4) -> ft.Control:
    """A cover, or a pixel-style note on the theme's colours when there's none."""
    if Data:
        return ft.Image(src=Data, width=Size, height=Size, fit=ft.BoxFit.COVER,
                        border_radius=Radius, filter_quality=ft.FilterQuality.MEDIUM, gapless_playback=True)
    return ft.Container(
        ft.Icon(ft.Icons.MUSIC_NOTE, color=Palette.Mauve, size=Size * 0.5),
        width=Size, height=Size, bgcolor=Palette.Surface0, border_radius=Radius,
        border=ft.Border.all(1, Palette.Surface1), alignment=ft.Alignment.CENTER,
    )


class Transport(ft.Container):
    def __init__(self, ThePlayer: Player, OnPrevious: Callable[[], Awaitable[None]],
                 OnNext: Callable[[], Awaitable[None]], OnVolume: Callable[[float], None],
                 Extras: Optional[list[ft.Control]] = None, OnInfoClick: Optional[Callable] = None):
        super().__init__(
            bgcolor=Palette.Mantle,
            border=ft.Border.only(top=ft.BorderSide(1, Palette.Surface1)),
            padding=ft.Padding.symmetric(horizontal=12, vertical=8),
        )
        self.ThePlayer = ThePlayer
        self._Dragging = False
        self.Shown = False  # set by Main: only the shown mode's bar is on the page

        self.Cover = ft.Container(CoverImage(None, CoverSize))
        self.Title = ft.Text("Nothing playing", color=Palette.Text, size=15, max_lines=1,
                             overflow=ft.TextOverflow.ELLIPSIS)
        self.Subtitle = ft.Text("", color=Palette.Overlay0, size=12, max_lines=1, overflow=ft.TextOverflow.ELLIPSIS)
        Info = ft.Container(
            ft.Row([self.Cover, ft.Column([self.Title, self.Subtitle], spacing=2, expand=True, tight=True)],
                   spacing=10),
            width=280, on_click=OnInfoClick, ink=OnInfoClick is not None, border_radius=4,
        )

        async def Previous(e) -> None:
            await OnPrevious()

        async def Next(e) -> None:
            await OnNext()

        async def Toggle(e) -> None:
            await ThePlayer.Toggle()

        self.PlayButton = ft.IconButton(
            ft.Icons.PLAY_ARROW_ROUNDED, icon_size=34, icon_color=Palette.Crust, bgcolor=Palette.Mauve,
            tooltip="Play / pause (space)", on_click=Toggle,
        )
        Buttons = ft.Row([
            ft.IconButton(ft.Icons.SKIP_PREVIOUS_ROUNDED, icon_color=Palette.Text, tooltip="Previous", on_click=Previous),
            self.PlayButton,
            ft.IconButton(ft.Icons.SKIP_NEXT_ROUNDED, icon_color=Palette.Text, tooltip="Next", on_click=Next),
        ], spacing=4)

        self.Elapsed = ft.Text("0:00", color=Palette.Overlay0, size=12, width=52, text_align=ft.TextAlign.RIGHT)
        self.Total = ft.Text("0:00", color=Palette.Overlay0, size=12, width=52)
        self.Seek = ft.Slider(
            min=0, max=1, value=0, expand=True, active_color=Palette.Mauve, inactive_color=Palette.Surface1,
            thumb_color=Palette.Mauve, on_change_start=self._DragStart, on_change=self._Dragged,
            on_change_end=self._DragEnd,
        )

        def VolumeChanged(e) -> None:
            OnVolume(e.control.value)
            self.VolumeIcon.icon = self._VolumeIconFor(e.control.value)
            self.VolumeIcon.update()

        self.VolumeIcon = ft.Icon(self._VolumeIconFor(ThePlayer.Volume), color=Palette.Overlay0, size=20)
        self.Volume = ft.Slider(min=0, max=1, value=ThePlayer.Volume, width=120, active_color=Palette.Mauve,
                                inactive_color=Palette.Surface1, thumb_color=Palette.Mauve, on_change=VolumeChanged)

        self.content = ft.Row([
            Info,
            Buttons,
            self.Elapsed, self.Seek, self.Total,
            *(Extras or []),
            self.VolumeIcon, self.Volume,
        ], spacing=8, vertical_alignment=ft.CrossAxisAlignment.CENTER)

    @staticmethod
    def _VolumeIconFor(Value: float):
        return ft.Icons.VOLUME_OFF if Value <= 0 else ft.Icons.VOLUME_DOWN if Value < 0.5 else ft.Icons.VOLUME_UP

    def SetVolume(self, Value: float) -> None:
        """The other mode's bar changed the shared volume."""
        self.Volume.value = Value
        self.VolumeIcon.icon = self._VolumeIconFor(Value)

    def ShowTrack(self, Title: str, Subtitle: str, Cover: Optional[bytes]) -> None:
        self.Title.value = Title
        self.Subtitle.value = Subtitle
        self.Cover.content = CoverImage(Cover, CoverSize)
        if self.Shown:
            self.update()

    # --- Seek bar -----------------------------------------------------------

    def _DragStart(self, e) -> None:
        self._Dragging = True

    def _Dragged(self, e) -> None:
        self.Elapsed.value = FormatTime(e.control.value)
        self.Elapsed.update()

    async def _DragEnd(self, e) -> None:
        self._Dragging = False
        await self.ThePlayer.Seek(int(e.control.value))

    def Refresh(self) -> None:
        """Play button, times and seek bar from the player; called by a
        ticker a few times a second while playing."""
        P = self.ThePlayer
        self.PlayButton.icon = ft.Icons.PAUSE_ROUNDED if P.Playing else ft.Icons.PLAY_ARROW_ROUNDED
        Duration = max(P.Duration, 1)
        self.Seek.max = Duration
        self.Seek.disabled = not P.Source
        self.Total.value = FormatTime(P.Duration)
        if not self._Dragging:
            self.Seek.value = min(P.Position, Duration)
            self.Elapsed.value = FormatTime(P.Position)
        if self.Shown:
            self.update()


async def Ticker(Bars: list[Transport], Interval: float = 0.25) -> None:
    """Keeps the playing bars moving. Runs for the app's lifetime."""
    while True:
        for Bar in Bars:
            if Bar.ThePlayer.Playing and Bar.Shown:
                Bar.Refresh()
        await asyncio.sleep(Interval)