feat: theme hyprlock from the UDT palette and accent

udt-palette renders the scheme-level palette to
templates/hyprlock/hyprlock-palette.conf ($panel, $input_bg, $text,
$subtext, $fail); udt-accent writes the wallpaper accent gradient to
~/.cache/udt/hyprlock-border.conf as a hyprlang variable. The hyprlock
config sources both, so a scheme switch recolours the lock and a
wallpaper change recolours its border.

install.sh copies the palette and seeds the border from the committed
fallback on a fresh cache. Both selftests cover the new outputs.

2 files changed, 77 insertions, 0 deletions

diff --git a/bin/udt-accent b/bin/udt-accent
index a862ae9..6462aae 100755
--- a/bin/udt-accent
+++ b/bin/udt-accent
@@ -34,6 +34,9 @@ MIN_CHROMA = 10.0
 CACHE = Path.home() / ".cache" / "udt"
 OUTPUT = CACHE / "udt-accent.rasi"
 BORDER_OUTPUT = CACHE / "udt-border.lua"
+# hyprlock cannot read the Lua border table, so the same three hues are also
+# written as a hyprlang variable the lock config sources. See write_hyprlock.
+HYPRLOCK_BORDER_OUTPUT = CACHE / "hyprlock-border.conf"
 SUBLIME = (Path.home() / ".config" / "sublime-text" / "Packages" / "User"
            / "udt.sublime-color-scheme")
 QML_OUTPUT = CACHE / "udt-palette.qml"
@@ -208,6 +211,28 @@ def write_border(name):
     write_atomic(BORDER_OUTPUT, content)
 
 
+def hyprlock_border_content(name):
+    """The hyprlock border gradient, as a hyprlang variable assignment.
+
+    The lock panel, its avatar ring and the password outline all take this
+    gradient: the same three hues the Hyprland window border rotates through,
+    so a wallpaper change recolours the lock with the rest of the desktop.
+    One `rgb(hex) rgb(hex) rgb(hex) <angle>` line, which is the syntax the
+    input-field already used before it followed the theme.
+    """
+    before, after = hue_neighbours(name)
+    stops = " ".join(f"rgb({ACCENTS[n].lstrip('#')})" for n in (before, name, after))
+    return (
+        "# Generated by udt-accent. Do not edit.\n"
+        f"$border = {stops} 45deg\n"
+    )
+
+
+def write_hyprlock_border(name):
+    """Write the hyprlock border gradient, atomically."""
+    write_atomic(HYPRLOCK_BORDER_OUTPUT, hyprlock_border_content(name))
+
+
 def read_palette():
     """Parse palette.rasi into {name: "#rrggbb"}.
 
@@ -429,6 +454,7 @@ def main(image):
 
     write_accent(name)
     write_border(name)
+    write_hyprlock_border(name)
     write_qml(name)
     write_sublime(name)
     write_sddm(name, image)
@@ -485,6 +511,15 @@ def selftest():
             delta = abs(_hue(ACCENTS[neighbour]) - _hue(ACCENTS[name]))
             assert min(delta, 2 * math.pi - delta) < math.pi, (name, neighbour)
 
+    # The lock border carries the same three hues as the window border, in
+    # hyprlang gradient syntax: three rgb() stops and an angle. Get it wrong and
+    # the panel border, avatar ring and password outline all draw hyprlock's
+    # default cyan instead of the accent.
+    lock = hyprlock_border_content(FALLBACK)
+    assert lock.count("rgb(") == 3, lock
+    assert lock.rstrip().endswith("45deg"), lock
+    assert "$border = " in lock, lock
+
     # The SDDM theme reads this file through a symlink, so it has to carry every
     # key the theme asks for. The names are spelled out here rather than read
     # from SDDM_KEYS: deriving both the input and the check from the same
diff --git a/bin/udt-palette b/bin/udt-palette
index 9bd3838..fbe53e6 100755
--- a/bin/udt-palette
+++ b/bin/udt-palette
@@ -260,6 +260,39 @@ def gen_kitty(res, scheme, palette):
     return "\n".join(lines) + "\n"
 
 
+def gen_hyprlock(res, scheme, palette):
+    """hyprlock: the lock screen's scheme-level palette, as hyprlang variables.
+
+    Only the values that move with the scheme. The accent border is a separate
+    generated file, written by udt-accent, because it follows the wallpaper
+    rather than the scheme; hyprlock.conf sources both.
+
+    The panel alpha is a design constant, not a role: it matches the drawer's
+    Qt.alpha(Theme.base, 0.72), so the lock panel and the drawer read as one
+    surface.
+    """
+    def with_alpha(role, alpha):
+        r, g, b, _ = res[role]
+        return f"rgba({r},{g},{b},{alpha})"
+
+    rows = [
+        ("panel",    with_alpha("bg", 0.72)),
+        ("input_bg", rgba(res["surface"])),
+        ("text",     rgba(res["fg"])),
+        ("subtext",  rgba(res["fg_dim"])),
+        ("fail",     rgba(res["critical"])),
+    ]
+    body = "\n".join(f"${name} = {value}" for name, value in rows)
+
+    return (
+        f"# {BANNER.format(scheme=scheme)}\n"
+        "#\n"
+        "# hyprlock's static palette. The accent border is generated separately\n"
+        "# by udt-accent, at ~/.cache/udt/hyprlock-border.conf.\n"
+        f"{body}\n"
+    )
+
+
 def gen_obsidian(res, scheme, palette):
     """Obsidian: a CSS snippet overriding the theme variables.
 
@@ -659,6 +692,7 @@ TARGETS = [
     ("rofi/udt/palette.rasi", gen_rofi, None),
     ("templates/waybar/theme.css", gen_waybar, None),
     ("templates/terminal/kitty-theme.conf", gen_kitty, None),
+    ("templates/hyprlock/hyprlock-palette.conf", gen_hyprlock, None),
     (str(CONKY_REPO / "conky.conf"), gen_conky, str(CONKY_REPO / "conky.conf.in")),
     ("bin/udt_colors.py", gen_accent_py, None),
     ("templates/homepage/custom.css", gen_homepage, None),
@@ -782,6 +816,14 @@ def selftest():
         assert not missing, f"{scheme} is missing roles: {sorted(missing)}"
         assert not extra, f"{scheme} has roles no other scheme has: {sorted(extra)}"
 
+    # The hyprlock palette must name every variable the lock config references.
+    # A missing one renders a literal `$var`, and hyprlock then falls back to a
+    # default colour with nothing to say so.
+    _, _, res, _ = load(None, scheme=names[0])
+    lock = gen_hyprlock(res, names[0], None)
+    for var in ("panel", "input_bg", "text", "subtext", "fail"):
+        assert f"${var} = " in lock, f"hyprlock palette is missing ${var}"
+
     # Every placeholder in the GTK templates must correspond to a role, or it
     # renders literally and GTK drops the declaration without an error. The
     # stylesheets are too large to eyeball, so this is the only thing standing