Add Mid Gray and Light Gray UI themes

docs/USER_GUIDE.md

@@ -826,6 +826,7 @@ Shows the whole strip, to place and pick the frames before the scan. **Apply Fra
 
 *   **Language**: English, Simplified Chinese, Japanese or Korean, after a restart.
 *   **UI scale**: 80% to 120%, after a restart.
+*   **UI theme**: **Black** (default), **Mid Gray** or **Light Gray** for the app's panels and chrome, after a restart.
 *   **Canvas background**: from black to white. Mid gray is best for judging a print.
 *   **Sticky Zoom**: keeps the zoom when you change frames. **Reverse Scroll Zoom**: scroll up zooms out.
 *   **Shortcut Hints** (on at first): after you use a control with the mouse, a toast on the canvas shows its keyboard shortcut, once per session.

negpy/desktop/main.py

@@ -332,6 +332,10 @@ def main() -> None:
         if scale != 1.0 and "QT_SCALE_FACTOR" not in os.environ:
             os.environ["QT_SCALE_FACTOR"] = f"{scale:.2f}"
 
+        from negpy.desktop.view.styles.theme import apply_theme
+
+        apply_theme(str(repo.get_global_setting("ui_theme", "black") or "black"))
+
         # Global attributes for Windows stability
         if sys.platform == "win32":
             QCoreApplication = getattr(sys.modules["PyQt6.QtCore"], "QCoreApplication")

negpy/desktop/view/styles/theme.py

@@ -1,6 +1,9 @@
+import dataclasses
 from dataclasses import dataclass, field
 from typing import Dict
 
+from negpy.kernel.system.i18n import mark
+
 
 @dataclass(frozen=True)
 class ThemeConfig:
@@ -157,3 +160,78 @@ class ThemeConfig:
 
 def scene_color(ordinal: int) -> str:
     return SCENE_COLORS[(ordinal - 1) % len(SCENE_COLORS)]
+
+
+# Preferences > Interface > UI Theme. Every "surfaces, darkest first" background and border
+# lightened by the same offset that turns bg_dark into a photographic middle gray (Light Gray), so the
+# depth ordering between panel, card and header is unchanged. The grays used for secondary
+# and hint copy go white, since they read too close to the new light-gray surfaces otherwise;
+# text_muted stays put, since it is documented as deliberately low-contrast (disabled only).
+# header_veil/_hover and surface_overlay/_hover are translucent washes over a card's chart
+# and over the canvas, not flat token reads, so each needs its own override beside bg_header.
+_LIGHT_GRAY_OVERRIDES: Dict[str, str] = {
+    "bg_dark": "#808080",
+    "bg_panel": "#808080",
+    "bg_input": "#7D7D7D",
+    "bg_card": "#858585",
+    "bg_header": "#898989",
+    "bg_selected": "#959595",
+    "bg_hover": "#999999",
+    "bg_menu_selected": "#A1A1A1",
+    "border_input": "#8D8D8D",
+    "border_primary": "#999999",
+    "border_color": "#A6A6A6",
+    "border_hover": "#ADADAD",
+    "border_indicator": "#B5B5B5",
+    "slider_disabled": "#C8C8C8",
+    "surface_overlay": "rgba(128,128,128,0.88)",
+    "surface_overlay_hover": "rgba(149,149,149,0.88)",
+    "header_veil": "rgba(141,141,141,0.55)",
+    "header_veil_hover": "rgba(149,149,149,0.62)",
+    "text_secondary": "#FFFFFF",
+    "text_hint": "#FFFFFF",
+    "text_unit": "#FFFFFF",
+}
+
+# Same lightening, anchored to canvas_bg_mid_grey (the "Mid Gray" canvas swatch). Still dark
+# enough that the existing text grays stay readable, so none of them need the white override above.
+_MID_GRAY_OVERRIDES: Dict[str, str] = {
+    "bg_dark": "#404040",
+    "bg_panel": "#404040",
+    "bg_input": "#3D3D3D",
+    "bg_card": "#454545",
+    "bg_header": "#494949",
+    "bg_selected": "#555555",
+    "bg_hover": "#595959",
+    "bg_menu_selected": "#616161",
+    "border_input": "#4D4D4D",
+    "border_primary": "#595959",
+    "border_color": "#666666",
+    "border_hover": "#6D6D6D",
+    "border_indicator": "#757575",
+    "slider_disabled": "#888888",
+    "surface_overlay": "rgba(64,64,64,0.88)",
+    "surface_overlay_hover": "rgba(85,85,85,0.88)",
+    "header_veil": "rgba(77,77,77,0.55)",
+    "header_veil_hover": "rgba(85,85,85,0.62)",
+}
+
+UI_THEMES: tuple[tuple[str, str], ...] = (
+    ("black", mark("Black (Default)")),
+    ("mid_gray", mark("Mid Gray")),
+    ("light_gray", mark("Light Gray")),
+)
+_THEME_OVERRIDES: Dict[str, Dict[str, str]] = {
+    "mid_gray": _MID_GRAY_OVERRIDES,
+    "light_gray": _LIGHT_GRAY_OVERRIDES,
+}
+_DEFAULT_THEME = ThemeConfig()
+
+
+def apply_theme(key: str) -> None:
+    """Patches the shared THEME instance in place so every module that already holds a
+    reference to it (imported at their own load time) picks up the chosen palette. Read once
+    at startup; switching requires a restart to repaint every baked stylesheet and icon."""
+    overrides = _THEME_OVERRIDES.get(key, {})
+    for f in dataclasses.fields(THEME):
+        object.__setattr__(THEME, f.name, overrides.get(f.name, getattr(_DEFAULT_THEME, f.name)))

negpy/desktop/view/widgets/preferences_dialog.py

@@ -19,7 +19,7 @@
 from negpy.desktop.controller import AppController
 from negpy.desktop.view.styles.color_vision import PALETTES
 from negpy.desktop.view.styles.templates import field_label, hint_label, labeled_action, labeled_toggle, pin_dialog_default
-from negpy.desktop.view.styles.theme import THEME
+from negpy.desktop.view.styles.theme import THEME, UI_THEMES
 from negpy.desktop.view.widgets.collapsible import CollapsibleSection
 from negpy.desktop.view.widgets.dialog_geometry import remember_dialog_geometry
 from negpy.desktop.view.widgets.semantic_download_dialog import ClipDownloadDialog
@@ -244,6 +244,16 @@ def _build_interface(self) -> QWidget:
         grid.addWidget(self.scale_combo, row, 1)
         row += 1
 
+        grid.addWidget(field_label(tr("UI theme")), row, 0)
+        self.theme_combo = StepCombo()
+        for key, label in UI_THEMES:
+            self.theme_combo.addItem(tr(label), key)
+        stored_theme = str(self.repo.get_global_setting("ui_theme", "black") or "black")
+        self.theme_combo.setCurrentIndex(max(self.theme_combo.findData(stored_theme), 0))
+        self.theme_combo.currentIndexChanged.connect(self._on_ui_theme_changed)
+        self.theme_combo.setToolTip(tr("Color of the app's panels and chrome"))
+        grid.addWidget(self.theme_combo, row, 1)
+        row += 1
         grid.addWidget(field_label(tr("Canvas background")), row, 0)
         self.canvas_combo = StepCombo()
         # Darkest to lightest; the item data is the saved index, which is not in that order.
@@ -484,6 +494,10 @@ def _on_ui_scale_changed(self, index: int) -> None:
         self.repo.save_global_setting("ui_scale", float(self.scale_combo.itemData(index)))
         self._mark_restart()
 
+    def _on_ui_theme_changed(self, index: int) -> None:
+        self.repo.save_global_setting("ui_theme", str(self.theme_combo.itemData(index)))
+        self._mark_restart()
+
     def _on_language_changed(self, index: int) -> None:
         self.repo.save_global_setting("ui_language", self.language_combo.currentData())
         self._mark_restart()

negpy/translations/USER_GUIDE.en.md

@@ -826,6 +826,7 @@ Shows the whole strip, to place and pick the frames before the scan. **Apply Fra
 
 *   **Language**: English, Simplified Chinese, Japanese or Korean, after a restart.
 *   **UI scale**: 80% to 120%, after a restart.
+*   **UI theme**: **Black** (default), **Mid Gray** or **Light Gray** for the app's panels and chrome, after a restart.
 *   **Canvas background**: from black to white. Mid gray is best for judging a print.
 *   **Sticky Zoom**: keeps the zoom when you change frames. **Reverse Scroll Zoom**: scroll up zooms out.
 *   **Shortcut Hints** (on at first): after you use a control with the mouse, a toast on the canvas shows its keyboard shortcut, once per session.

negpy/translations/ja.json

@@ -265,6 +265,7 @@
   "Bit depth": "ビット深度",
   "Bits per channel in the scanned file": "スキャンされたファイルのチャネルあたりのビット数",
   "Black": "ブラック",
+  "Black (Default)": "ブラック（デフォルト）",
   "Black Point": "黒点",
   "Black Point Compensation": "黒点補正",
   "Black Point Trim": "ブラックポイントトリム",
@@ -510,6 +511,7 @@
   "Color added to the highlights.": "ハイライトに加える色。",
   "Color added to the shadows.": "シャドウに加える色。",
   "Color negatives only: use the roll's gray balance for Cast Removal, so frames under one light match.": "カラーネガのみ: 色かぶり除去にロールのグレーバランスを使い、同じ光で撮ったフレームをそろえます。",
+  "Color of the app's panels and chrome": "アプリのパネルとインターフェースの色",
   "Color or black and white, negative or slide": "カラーか白黒か、ネガかスライドか",
   "Color range clip down": "色範囲クリップダウン",
   "Color range clip up": "色範囲クリップアップ",
@@ -2747,6 +2749,7 @@
   "Type a search first, e.g. film:portra": "先に検索条件を入力してください。例：film:portra",
   "Type a slider, card or action, or another editor's word for it: contrast, white balance.": "スライダー、カード、操作、または他の編集ソフトでの呼び名（コントラスト、ホワイトバランスなど）を入力します。",
   "UI scale": "UIスケール",
+  "UI theme": "UIテーマ",
   "USE AVERAGE": "平均を使用",
   "UV exposure time: more makes the print bluer, and less makes it paler.": "UV 露光時間: 多いほど青く、少ないほど淡くなります。",
   "Unavailable: {reason}": "利用不可: {reason}",

negpy/translations/ko.json

@@ -265,6 +265,7 @@
   "Bit depth": "비트 심도",
   "Bits per channel in the scanned file": "스캔한 파일의 채널당 비트",
   "Black": "블랙",
+  "Black (Default)": "블랙(기본값)",
   "Black Point": "블랙 포인트",
   "Black Point Compensation": "블랙 포인트 보상",
   "Black Point Trim": "블랙 포인트 트림",
@@ -510,6 +511,7 @@
   "Color added to the highlights.": "밝은 영역에 더하는 색입니다.",
   "Color added to the shadows.": "어두운 영역에 더하는 색입니다.",
   "Color negatives only: use the roll's gray balance for Cast Removal, so frames under one light match.": "컬러 네거티브 전용: 색 편향 제거에 롤의 회색 균형을 써서 같은 빛에서 찍은 프레임을 맞춥니다.",
+  "Color of the app's panels and chrome": "앱 패널과 인터페이스의 색상",
   "Color or black and white, negative or slide": "컬러 또는 흑백, 네거티브 또는 슬라이드",
   "Color range clip down": "색상 범위 클립 다운",
   "Color range clip up": "색상 범위 클립 업",
@@ -2747,6 +2749,7 @@
   "Type a search first, e.g. film:portra": "먼저 검색 조건을 입력하세요. 예: film:portra",
   "Type a slider, card or action, or another editor's word for it: contrast, white balance.": "슬라이더, 카드, 동작 이름이나 다른 편집 앱에서 쓰는 말(대비, 화이트 밸런스 등)을 입력하세요.",
   "UI scale": "UI 배율",
+  "UI theme": "UI 테마",
   "USE AVERAGE": "평균 사용",
   "UV exposure time: more makes the print bluer, and less makes it paler.": "UV 노출 시간: 많을수록 더 파랗고, 적을수록 더 옅어집니다.",
   "Unavailable: {reason}": "사용할 수 없음: {reason}",

negpy/translations/zh_CN.json

@@ -265,6 +265,7 @@
   "Bit depth": "位深",
   "Bits per channel in the scanned file": "扫描文件每个通道的位数",
   "Black": "黑色",
+  "Black (Default)": "黑色（默认）",
   "Black Point": "黑点",
   "Black Point Compensation": "黑点补偿",
   "Black Point Trim": "黑点微调",
@@ -510,6 +511,7 @@
   "Color added to the highlights.": "加到高光的颜色。",
   "Color added to the shadows.": "加到暗部的颜色。",
   "Color negatives only: use the roll's gray balance for Cast Removal, so frames under one light match.": "仅限彩色负片：去色偏使用整卷的灰平衡，让同一光线下的各帧一致。",
+  "Color of the app's panels and chrome": "应用面板和界面的颜色",
   "Color or black and white, negative or slide": "彩色或黑白，负片或反转片",
   "Color range clip down": "减小颜色范围截断",
   "Color range clip up": "增大颜色范围截断",
@@ -2747,6 +2749,7 @@
   "Type a search first, e.g. film:portra": "请先输入搜索内容，例如 film:portra",
   "Type a slider, card or action, or another editor's word for it: contrast, white balance.": "输入滑块、卡片或操作名称，也可使用反差、白平衡等常用词。",
   "UI scale": "界面缩放",
+  "UI theme": "界面主题",
   "USE AVERAGE": "使用平均值",
   "UV exposure time: more makes the print bluer, and less makes it paler.": "紫外曝光时间：越多越蓝，越少越浅。",
   "Unavailable: {reason}": "不可用：{reason}",

tests/test_ui_theme.py

@@ -0,0 +1,50 @@
+import dataclasses
+
+import pytest
+
+from negpy.desktop.view.styles import theme
+from negpy.desktop.view.styles.theme import THEME, UI_THEMES, ThemeConfig, apply_theme
+
+
+@pytest.fixture(autouse=True)
+def _restore_default_theme():
+    yield
+    apply_theme("black")
+
+
+def test_black_leaves_every_token_at_its_default():
+    apply_theme("mid_gray")
+    apply_theme("black")
+    assert dataclasses.asdict(THEME) == dataclasses.asdict(ThemeConfig())
+
+
+def test_an_unknown_key_falls_back_to_black():
+    apply_theme("light_gray")
+    apply_theme("no_such_theme")
+    assert dataclasses.asdict(THEME) == dataclasses.asdict(ThemeConfig())
+
+
+@pytest.mark.parametrize("key", ["mid_gray", "light_gray"])
+def test_a_gray_theme_retints_the_surfaces_in_place(key: str):
+    before = THEME
+    apply_theme(key)
+    assert THEME is before
+    assert THEME.bg_dark != ThemeConfig().bg_dark
+    assert THEME.bg_dark == theme._THEME_OVERRIDES[key]["bg_dark"]
+
+
+def test_switching_themes_does_not_leak_the_previous_override():
+    apply_theme("light_gray")
+    assert THEME.text_secondary == "#FFFFFF"
+    apply_theme("mid_gray")
+    assert THEME.text_secondary == ThemeConfig().text_secondary
+
+
+def test_every_override_names_a_real_token():
+    tokens = {f.name for f in dataclasses.fields(ThemeConfig)}
+    for key, overrides in theme._THEME_OVERRIDES.items():
+        assert set(overrides) <= tokens, key
+
+
+def test_every_listed_theme_resolves():
+    assert {key for key, _ in UI_THEMES} == {"black", *theme._THEME_OVERRIDES}