feat(palette): sixteen ANSI colour ladders, cycled with c

beefy_player/widgets/frame.py

@@ -1,9 +1,12 @@
-"""Pane frames: one grey box, with two corners fading out of it.
+"""Pane frames: one grey box whose corners glow in the active palette.
 
 The panes draw their own frames instead of using Textual's ``border`` so the
-corners can be coloured individually.  Two of them — the top right and the
-bottom left — run white → light grey → bright cyan → cyan along both arms;
-everything else, including the other two corners, is the border grey.
+corners can be coloured.  Two of them — the top right and the bottom left —
+run a short fade out of the palette's hot end and back into the border grey;
+everything else, including the other two corners, is that grey.
+
+The ladder is whatever palette the app is on (``c`` cycles them), which is why
+every function here takes ``stops`` rather than reading a module constant.
 """
 
 from __future__ import annotations
@@ -13,26 +16,30 @@ from rich.console import Group, RenderableType
 from rich.text import Text
 from textual.widget import Widget
 
+from ..palettes import DEFAULT_PALETTE, PALETTES
+from .common import active_stops
+
 #: The frame itself: one grey, the same grey as the scrollbar thumb.
 EDGE = "bright_black"
 
-#: A faded corner runs white → light grey → bright cyan → cyan, then settles
-#: back into the border grey.
-CORNER_GRADIENT = ("bright_white", "white", "bright_cyan", "cyan")
+#: How many cells a corner fade reaches into the edge.
+FADE_CELLS = 4
 
 
-def fade(distance: int) -> str:
-    """Colour ``distance`` cells away from a corner (0 is the corner itself)."""
-    if 0 <= distance < len(CORNER_GRADIENT):
-        return CORNER_GRADIENT[distance]
-    return EDGE
+def corner_fade(distance: int, stops: tuple[str, ...] = ()) -> str:
+    """Colour ``distance`` cells out from a corner; 0 is the corner glyph.
 
-
-def side_style(row: int, rows: int, side: str = "left") -> str:
-    """Colour of a side cell: only two corners fade, so only one end glows."""
-    if side == "right":
-        return fade(row + 1)  # fades down from the top-right corner
-    return fade(rows - row)  # fades up from the bottom-left corner
+    The fade is short — four cells — and walks backwards down the palette from
+    its hot end, so the corner glows in the palette's brightest colour and then
+    hands over to the plain border grey.
+    """
+    if not stops:
+        stops = PALETTES[DEFAULT_PALETTE]
+    distance = max(0, distance)
+    if distance >= FADE_CELLS:
+        return EDGE
+    index = len(stops) - 1 - distance
+    return stops[index] if index >= 0 else EDGE
 
 
 def inner_size(width: int, height: int) -> tuple[int, int]:
@@ -40,12 +47,12 @@ def inner_size(width: int, height: int) -> tuple[int, int]:
     return max(1, width - 2), max(1, height - 2)
 
 
-def _edge_cells(width: int, faded_end: str = "right") -> list[tuple[str, str]]:
+def _edge_cells(width: int, faded_end: str, stops: tuple[str, ...]) -> list[tuple[str, str]]:
     """Inner cells of an edge; only one end of it fades into a corner."""
     inner = max(0, width - 2)
     if faded_end == "left":
-        return [("─", fade(column + 1)) for column in range(inner)]
-    return [("─", fade(inner - column)) for column in range(inner)]
+        return [("─", corner_fade(column + 1, stops)) for column in range(inner)]
+    return [("─", corner_fade(inner - column, stops)) for column in range(inner)]
 
 
 def _paint(line: Text, cells: list[tuple[str, str]]) -> None:
@@ -62,9 +69,9 @@ def _paint(line: Text, cells: list[tuple[str, str]]) -> None:
         line.append("".join(run), style=style)
 
 
-def top(width: int, title: str = "") -> Text:
+def top(width: int, title: str = "", stops: tuple[str, ...] = ()) -> Text:
     width = max(2, width)
-    cells = _edge_cells(width, "right")  # only the top-right corner fades
+    cells = _edge_cells(width, "right", stops)  # only the top-right corner fades
     if title:
         label = f" {title} "
         start = 1
@@ -75,29 +82,38 @@ def top(width: int, title: str = "") -> Text:
     line = Text(no_wrap=True)
     line.append("╭", style=EDGE)
     _paint(line, cells)
-    line.append("╮", style=f"bold {fade(0)}")
+    line.append("╮", style=f"bold {corner_fade(0, stops)}")
     return line
 
 
-def bottom(width: int) -> Text:
+def bottom(width: int, stops: tuple[str, ...] = ()) -> Text:
     width = max(2, width)
     line = Text(no_wrap=True)
-    line.append("╰", style=f"bold {fade(0)}")
-    _paint(line, _edge_cells(width, "left"))  # only the bottom-left fades
+    line.append("╰", style=f"bold {corner_fade(0, stops)}")
+    _paint(line, _edge_cells(width, "left", stops))  # only the bottom-left fades
     line.append("╯", style=EDGE)
     return line
 
 
-def side() -> Text:
-    return Text("│", style=EDGE)
+def side_style(row: int, rows: int, side: str = "left", stops: tuple[str, ...] = ()) -> str:
+    """Colour of a side cell: only two corners fade, so only one end glows."""
+    if side == "right":
+        return corner_fade(row + 1, stops)  # fades down from the top-right corner
+    return corner_fade(rows - row, stops)  # fades up from the bottom-left corner
 
 
-def side_row(row: int, rows: int, side: str = "left") -> Text:
-    return Text("│", style=side_style(row, rows, side))
+def side_row(
+    row: int, rows: int, side: str = "left", stops: tuple[str, ...] = ()
+) -> Text:
+    return Text("│", style=side_style(row, rows, side, stops))
 
 
 def wrap(
-    lines: list[Text], width: int, height: int, title: str = ""
+    lines: list[Text],
+    width: int,
+    height: int,
+    title: str = "",
+    stops: tuple[str, ...] = (),
 ) -> RenderableType:
     """Frame ``lines`` (already sized for the content box) in a pane."""
     width = max(4, width)
@@ -105,24 +121,29 @@ def wrap(
     inner_width, inner_height = inner_size(width, height)
     rows = len(lines[:inner_height])
 
-    framed: list[Text] = [top(width, title)]
+    framed: list[Text] = [top(width, title, stops)]
     for index, line in enumerate(lines[:inner_height]):
+        if cell_len(line.plain) > inner_width:
+            # A pane must never spill over its neighbour: trim, whatever the
+            # caller asked for.
+            line = line.copy()
+            line.truncate(inner_width, overflow="ellipsis")
         row = Text(no_wrap=True)
-        row.append_text(side_row(index, rows, "left"))
+        row.append_text(side_row(index, rows, "left", stops))
         row.append_text(line)
         pad = inner_width - cell_len(line.plain)
         if pad > 0:
             row.append(" " * pad)
-        row.append_text(side_row(index, rows, "right"))
+        row.append_text(side_row(index, rows, "right", stops))
         framed.append(row)
     while len(framed) < height - 1:
         index = len(framed) - 1
         row = Text(no_wrap=True)
-        row.append_text(side_row(index, inner_height, "left"))
+        row.append_text(side_row(index, inner_height, "left", stops))
         row.append(" " * inner_width)
-        row.append_text(side_row(index, inner_height, "right"))
+        row.append_text(side_row(index, inner_height, "right", stops))
         framed.append(row)
-    framed.append(bottom(width))
+    framed.append(bottom(width, stops))
     return Group(*framed[:height])
 
 
@@ -139,14 +160,14 @@ class FrameTop(Widget):
         self.title = title
 
     def render(self) -> RenderableType:
-        return top(max(2, self.size.width), self.title)
+        return top(max(2, self.size.width), self.title, active_stops(self.app))
 
 
 class FrameBottom(Widget):
     can_focus = False
 
     def render(self) -> RenderableType:
-        return bottom(max(2, self.size.width))
+        return bottom(max(2, self.size.width), active_stops(self.app))
 
 
 class FrameSide(Widget):
@@ -158,6 +179,7 @@ class FrameSide(Widget):
 
     def render(self) -> RenderableType:
         rows = max(1, self.size.height)
+        stops = active_stops(self.app)
         return Group(
-            *[side_row(row, rows, self.side) for row in range(rows)]
+            *[side_row(row, rows, self.side, stops) for row in range(rows)]
         )