feat(tui): implement SomaFM terminal radio player

somafm_tui/widgets/header.py

@@ -0,0 +1,97 @@
+"""Header: logo, clock and a live ticker."""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, cast
+
+from rich.cells import cell_len
+from rich.console import Group, RenderableType
+from rich.text import Text
+from textual.widget import Widget
+
+from .common import (
+    SPECTRUM_STOPS,
+    clock_time,
+    date_label,
+    gradient,
+    marquee,
+    state_glyph,
+)
+
+if TYPE_CHECKING:
+    from ..app import SomaFMApp
+
+LOGO = (
+    "▄▀▀▀ ▄▀▀▄ █▄ ▄█ ▄▀▀▄",
+    "▀▀▀▄ █  █ █ █ █ █▀▀█",
+    "▄▄▄▀ ▀▄▄▀ █   █ █  █",
+)
+
+MIDDLE = ("SOMA FM RADIO", "LISTENER SUPPORTED", "SAN FRANCISCO")
+
+
+class HeaderBar(Widget):
+    can_focus = False
+
+    def render(self) -> RenderableType:
+        app = cast("SomaFMApp", self.app)
+        width = max(24, self.size.width)
+        height = max(1, self.size.height)
+        state = app.playing_state
+        glyph, colour = state_glyph(state)
+
+        logo_width = max(len(row) for row in LOGO)
+        middle_width = max(len(row) for row in MIDDLE)
+        right = (clock_time(), date_label(), f"vol {app.volume}%")
+        right_width = max(len(item) for item in right)
+
+        show_middle = width >= logo_width + middle_width + 8
+        show_right = width >= logo_width + right_width + 8
+        if show_middle and show_right:
+            show_middle = width >= logo_width + 4 + middle_width + 2 + right_width
+
+        lines: list[Text] = []
+        for index, row in enumerate(LOGO):
+            line = Text(no_wrap=True)
+            for column, char in enumerate(row):
+                position = (
+                    column / max(1, logo_width - 1) + index * 0.055
+                ) % 1.0
+                line.append(
+                    char, style=f"bold {gradient(SPECTRUM_STOPS, position)}"
+                )
+            if show_middle:
+                line.append(" " * 4)
+                line.append(MIDDLE[index], style="dim")
+            if show_right:
+                used = logo_width
+                if show_middle:
+                    used += 4 + middle_width
+                pad = max(1, width - used - right_width)
+                line.append(" " * pad)
+                style = "bold" if index == 0 else "dim"
+                line.append(right[index], style=style)
+            lines.append(line)
+
+        if height >= 4:
+            ticker = Text(no_wrap=True)
+            prefix = f"{glyph} {state.upper():<8}  "
+            ticker.append(prefix, style=f"bold {colour}")
+            station = app.current
+            if app.notice:
+                text = app.notice
+                text_style = "italic yellow"
+            elif station is not None:
+                song = station.now_playing
+                if song is not None:
+                    text = f"{station.title}  ·  {song.display_artist} — {song.display_title}"
+                else:
+                    text = f"{station.title}  ·  {station.description}"
+                text_style = ""
+            else:
+                text = "Pick a station — press enter to tune in"
+                text_style = "italic dim"
+            ticker.append(marquee(text, max(4, width - cell_len(prefix))), style=text_style)
+            lines.append(ticker)
+
+        return Group(*lines[:height])