feat: add configurable theme with semantic color roles

src/IO/UI.py

@@ -14,10 +14,10 @@ class UI:
         self._app = app
 
     HEADER_ROWS = 2
-    ERROR_COLOR = 5
 
     def _get_attr(self, item: any, index: int) -> str:
-        attr = curses.color_pair(item.color_pair)
+        pair = self.app.config.theme.pair_for(item.color_role)
+        attr = curses.color_pair(pair)
         if index == self.app.navigator.cursor.pos:
             attr |= curses.A_REVERSE
         return attr
@@ -29,8 +29,9 @@ class UI:
 
         stdscr.addstr(0, 0, str(navigator.history[-1])[:width - 1])
         if navigator.error:
+            error_pair = self.app.config.theme.pair_for("error")
             stdscr.addstr(1, 0, navigator.error[:width - 1],
-                          curses.color_pair(self.ERROR_COLOR))
+                          curses.color_pair(error_pair))
 
         items = navigator.items
         available = max(0, height - self.HEADER_ROWS)
@@ -62,8 +63,10 @@ class UI:
         stdscr.addstr(row, 0, name.ljust(col_width), attr)
 
         if type(item) is Symlink:
+            target_pair = self.app.config.theme.pair_for(
+                Symlink.target_role(item.point_to))
             attr_arrow = curses.color_pair(0)
-            attr_target = curses.color_pair(Symlink.target_color(item.point_to))
+            attr_target = curses.color_pair(target_pair)
             if index == self.app.navigator.cursor.pos:
                 attr_arrow |= curses.A_REVERSE
                 attr_target |= curses.A_REVERSE

src/core/App.py

@@ -23,11 +23,7 @@ class App():
         curses.curs_set(0)
         curses.start_color()
         curses.use_default_colors()
-        curses.init_pair(1, curses.COLOR_WHITE, -1)
-        curses.init_pair(2, curses.COLOR_BLUE, -1)
-        curses.init_pair(3, curses.COLOR_CYAN, -1)
-        curses.init_pair(4, curses.COLOR_YELLOW, -1)
-        curses.init_pair(5, curses.COLOR_RED, -1)
+        self.config.theme.init_curses()
         stdscr.clear()
         while (True):
             self.navigator.refresh()

src/core/Config.py

@@ -4,6 +4,7 @@ import sys
 import tomllib
 from pathlib import Path
 from . import Sort
+from .Theme import Theme
 
 DEFAULT_KEYBINDS: dict[str, list[str]] = {
     "quit": ["q"],
@@ -20,10 +21,11 @@ DEFAULT_CURSOR_RESET = "top"
 
 class Config:
     def __init__(self, keybinds: dict[str, list[str]], cursor_reset: str,
-                 sort_mode: str) -> None:
+                 sort_mode: str, theme: Theme) -> None:
         self._keybinds = keybinds
         self._cursor_reset = cursor_reset
         self._sort_mode = sort_mode
+        self._theme = theme
         self._key_to_action: dict[str, str] = {
             key: action
             for action, keys in keybinds.items()
@@ -51,7 +53,8 @@ class Config:
             print(f"pyexplorer: unknown sort mode {sort_mode!r}, "
                   f"falling back to {Sort.DEFAULT_MODE!r}", file=sys.stderr)
             sort_mode = Sort.DEFAULT_MODE
-        return cls(keybinds, cursor_reset, sort_mode)
+        theme = Theme.load(data)
+        return cls(keybinds, cursor_reset, sort_mode, theme)
 
     @staticmethod
     def _default_path() -> Path:
@@ -71,3 +74,7 @@ class Config:
     @property
     def sort_mode(self) -> str:
         return self._sort_mode
+
+    @property
+    def theme(self) -> Theme:
+        return self._theme

src/core/Theme.py

@@ -0,0 +1,53 @@
+from __future__ import annotations
+import curses
+import sys
+
+COLOR_NAMES: dict[str, int] = {
+    "black": curses.COLOR_BLACK,
+    "red": curses.COLOR_RED,
+    "green": curses.COLOR_GREEN,
+    "yellow": curses.COLOR_YELLOW,
+    "blue": curses.COLOR_BLUE,
+    "magenta": curses.COLOR_MAGENTA,
+    "cyan": curses.COLOR_CYAN,
+    "white": curses.COLOR_WHITE,
+}
+
+ROLES = ["file", "folder", "symlink", "broken_symlink", "error"]
+
+DEFAULT_COLORS: dict[str, str] = {
+    "file": "white",
+    "folder": "blue",
+    "symlink": "cyan",
+    "broken_symlink": "red",
+    "error": "red",
+}
+
+
+class Theme:
+    def __init__(self, colors: dict[str, str]) -> None:
+        self._colors = colors
+        self._pair_for_role = {role: i + 1 for i, role in enumerate(ROLES)}
+
+    @classmethod
+    def load(cls, data: dict) -> Theme:
+        colors = dict(DEFAULT_COLORS)
+        for role, name in data.get("theme", {}).items():
+            if role not in ROLES:
+                print(f"pyexplorer: unknown theme role {role!r}, ignoring",
+                      file=sys.stderr)
+                continue
+            if name not in COLOR_NAMES:
+                print(f"pyexplorer: unknown color {name!r} for {role!r}, "
+                      f"ignoring", file=sys.stderr)
+                continue
+            colors[role] = name
+        return cls(colors)
+
+    def init_curses(self) -> None:
+        for role in ROLES:
+            curses.init_pair(self._pair_for_role[role],
+                              COLOR_NAMES[self._colors[role]], -1)
+
+    def pair_for(self, role: str) -> int:
+        return self._pair_for_role[role]

src/items/AItems.py

@@ -15,7 +15,7 @@ class AItem(ABC):
         self._path = path
         self.update()
 
-    COLOR = 0
+    COLOR_ROLE = "file"
 
     def update(self) -> None:
         self._stat = self._path.lstat()
@@ -48,5 +48,5 @@ class AItem(ABC):
         return self._permissions
 
     @property
-    def color_pair(self) -> int:
-        return self.COLOR
+    def color_role(self) -> str:
+        return self.COLOR_ROLE

src/items/File.py

@@ -3,7 +3,7 @@ from .AItems import AItem
 
 
 class File(AItem):
-    COLOR = 1
+    COLOR_ROLE = "file"
 
     def __init__(self, path: Path) -> None:
         super().__init__(path)

src/items/Folder.py

@@ -3,7 +3,7 @@ from .AItems import AItem
 
 
 class Folder(AItem):
-    COLOR = 2
+    COLOR_ROLE = "folder"
 
     def __init__(self, path: Path) -> None:
         super().__init__(path)

src/items/Symlink.py

@@ -5,7 +5,7 @@ from .Folder import Folder
 
 
 class Symlink(AItem):
-    COLOR = 3
+    COLOR_ROLE = "symlink"
 
     def __init__(self, path: Path) -> None:
         super().__init__(path)
@@ -18,13 +18,13 @@ class Symlink(AItem):
                                  self.point_to.name}"
 
     @staticmethod
-    def target_color(point_to: Path | None) -> int:
+    def target_role(point_to: Path | None) -> str:
         if point_to is None:
-            return 5
+            return "broken_symlink"
         elif point_to.is_dir():
-            return Folder.COLOR
+            return Folder.COLOR_ROLE
         else:
-            return File.COLOR
+            return File.COLOR_ROLE
 
     @property
     def point_to(self) -> Path: