Refactor app layout and load defaults from config

app/__init__.py

@@ -1,4 +1,4 @@
-"""ColorCalc application package."""
+"""Application package."""
 
 from .app import PurpleTunerApp, start_app
 

app/app.py

@@ -4,13 +4,8 @@ from __future__ import annotations
 
 import tkinter as tk
 
-from .color_picker import ColorPickerMixin
-from .constants import DEFAULTS
-from .exclusions import ExclusionMixin
-from .image_processing import ImageProcessingMixin
-from .reset import ResetMixin
-from .theme import ThemeMixin
-from .ui import UIBuilderMixin
+from .gui import ColorPickerMixin, ExclusionMixin, ThemeMixin, UIBuilderMixin
+from .logic import DEFAULTS, ImageProcessingMixin, ResetMixin
 
 
 class PurpleTunerApp(

app/gui/__init__.py

@@ -0,0 +1,14 @@
+"""GUI-related mixins and helpers for the application."""
+
+from .color_picker import ColorPickerMixin
+from .exclusions import ExclusionMixin
+from .theme import ThemeMixin, HAS_TTKBOOTSTRAP
+from .ui import UIBuilderMixin
+
+__all__ = [
+    "ColorPickerMixin",
+    "ExclusionMixin",
+    "ThemeMixin",
+    "HAS_TTKBOOTSTRAP",
+    "UIBuilderMixin",
+]

app/logic/__init__.py

@@ -0,0 +1,14 @@
+"""Logic utilities and mixins for processing and configuration."""
+
+from .constants import BASE_DIR, DEFAULTS, IMAGES_DIR, PREVIEW_MAX_SIZE
+from .image_processing import ImageProcessingMixin
+from .reset import ResetMixin
+
+__all__ = [
+    "BASE_DIR",
+    "DEFAULTS",
+    "IMAGES_DIR",
+    "PREVIEW_MAX_SIZE",
+    "ImageProcessingMixin",
+    "ResetMixin",
+]

app/logic/constants.py

@@ -0,0 +1,66 @@
+"""Shared configuration constants for the application."""
+
+from __future__ import annotations
+
+import contextlib
+from pathlib import Path
+from typing import Any, Callable
+
+try:  # Python 3.11 and above
+    import tomllib  # type: ignore[attr-defined]
+except ModuleNotFoundError:  # pragma: no cover - fallback for <3.11
+    with contextlib.suppress(ModuleNotFoundError):
+        import tomli as tomllib  # type: ignore[assignment]
+    if "tomllib" not in globals():
+        tomllib = None  # type: ignore[assignment]
+
+PREVIEW_MAX_SIZE = (1200, 800)
+
+BASE_DIR = Path(__file__).resolve().parents[2]
+IMAGES_DIR = BASE_DIR / "images"
+CONFIG_FILE = BASE_DIR / "config.toml"
+
+_DEFAULTS_BASE = {
+    "hue_min": 250.0,
+    "hue_max": 310.0,
+    "sat_min": 15.0,
+    "val_min": 15.0,
+    "val_max": 100.0,
+    "alpha": 120,
+}
+
+_DEFAULT_TYPES: dict[str, Callable[[Any], Any]] = {
+    "hue_min": float,
+    "hue_max": float,
+    "sat_min": float,
+    "val_min": float,
+    "val_max": float,
+    "alpha": int,
+}
+
+
+def _load_default_overrides() -> dict[str, Any]:
+    """Load default slider overrides from config.toml if available."""
+    if tomllib is None or not CONFIG_FILE.exists():
+        return {}
+    decode_error = getattr(tomllib, "TOMLDecodeError", ValueError)  # type: ignore[attr-defined]
+    try:
+        with CONFIG_FILE.open("rb") as handle:
+            data = tomllib.load(handle)
+    except (OSError, AttributeError, decode_error, TypeError):  # type: ignore[arg-type]
+        return {}
+    settings = data.get("defaults")
+    if not isinstance(settings, dict):
+        return {}
+    overrides: dict[str, Any] = {}
+    for key, caster in _DEFAULT_TYPES.items():
+        if key not in settings:
+            continue
+        try:
+            overrides[key] = caster(settings[key])
+        except (TypeError, ValueError):
+            continue
+    return overrides
+
+
+DEFAULTS = {**_DEFAULTS_BASE, **_load_default_overrides()}

colorcalc/constants.py

@@ -1,19 +0,0 @@
-"""Shared configuration constants for ColorCalc."""
-
-from __future__ import annotations
-
-from pathlib import Path
-
-PREVIEW_MAX_SIZE = (1200, 800)
-
-DEFAULTS = {
-    "hue_min": 250.0,
-    "hue_max": 310.0,
-    "sat_min": 15.0,
-    "val_min": 15.0,
-    "val_max": 100.0,
-    "alpha": 120,
-}
-
-BASE_DIR = Path(__file__).resolve().parent.parent
-IMAGES_DIR = BASE_DIR / "images"

config.toml

@@ -0,0 +1,10 @@
+[defaults]
+# Override any of the following keys to tweak the initial slider values:
+# hue_min, hue_max, sat_min, val_min, val_max accept floating point numbers.
+# alpha accepts an integer between 0 and 255.
+hue_min = 250.0
+hue_max = 310.0
+sat_min = 15.0
+val_min = 15.0
+val_max = 100.0
+alpha = 120

main.py

@@ -1,6 +1,6 @@
-"""CLI entry point for the ColorCalc application."""
+"""CLI entry point for the application."""
 
-from colorcalc import start_app
+from app import start_app
 
 
 if __name__ == "__main__":