refactor(ui): color the cursor and modeline from theme faces, in sync

The cursor color and the modeline buffer-name indicator both hard-coded hex colors through cj/buffer-status-colors. Replaced that constant with cj/buffer-status-faces, mapping each buffer state to a theme face: read-only to error, overwrite and modified to warning, unmodified to success. A shared classifier (cj/buffer-status-state) and resolver (cj/buffer-status-color) in user-constants now drive both consumers, so the cursor and the modeline resolve their color from the active theme at use time and stay in sync, including the ghostel-terminal case the cursor already special-cased. Tests cover the map, the classifier, the resolver, and both integration paths.

1 files changed, 38 insertions, 7 deletions

diff --git a/modules/user-constants.el b/modules/user-constants.el
index 2e64b355e..1ee8ecda3 100644
--- a/modules/user-constants.el
+++ b/modules/user-constants.el
@@ -55,13 +55,44 @@ mail, chime, etc."
 
 ;; ---------------------------- Buffer Status Colors ---------------------------
 
-(defconst cj/buffer-status-colors
-  '((read-only  . "#f06a3f")  ; red   – buffer is read-only
-    (overwrite  . "#c48702")  ; gold  – overwrite mode
-    (modified   . "#64aa0f")  ; green – modified & writeable
-    (unmodified . "#ffffff")) ; white – unmodified & writeable
-  "Alist mapping buffer states to their colors.
-Used by cursor color, modeline, and other UI elements.")
+(defconst cj/buffer-status-faces
+  '((read-only  . error)     ; can't edit
+    (overwrite  . warning)   ; overwrite mode
+    (modified   . warning)   ; writeable, with unsaved changes
+    (unmodified . success))  ; clean and writeable
+  "Alist mapping a buffer state to the theme face whose foreground colors it.
+Shared by the cursor color (ui-config.el) and the modeline buffer-status
+indicator (modeline-config.el) so the two stay in sync and follow the active
+theme, rather than hard-coding hex colors.")
+
+(defun cj/buffer-status-state ()
+  "Return the buffer-state symbol for the current buffer.
+One of `read-only', `overwrite', `modified', or `unmodified' -- the keys of
+`cj/buffer-status-faces'.
+
+A live ghostel terminal (in `ghostel-mode' and an input mode that forwards keys
+-- semi-char / char / line) reports `unmodified' even though the buffer is
+read-only: keystrokes go to the terminal process, so from the user's side it is
+writeable and the read-only state would be misleading.  ghostel's `copy' and
+`emacs' input modes are the exception -- there the buffer really is a read-only
+Emacs buffer the user navigates, so it falls through to `read-only'."
+  (cond
+   ((and (eq major-mode 'ghostel-mode)
+         (not (memq (bound-and-true-p ghostel--input-mode) '(copy emacs))))
+    'unmodified)
+   (buffer-read-only    'read-only)
+   (overwrite-mode      'overwrite)
+   ((buffer-modified-p) 'modified)
+   (t                   'unmodified)))
+
+(defun cj/buffer-status-color (state)
+  "Return the foreground color of the theme face mapped to buffer STATE.
+Resolves STATE through `cj/buffer-status-faces' against the active theme.  Nil
+when the state is unknown or its face has no concrete foreground (face-attribute
+returns the symbol `unspecified' there), so callers can skip cleanly."
+  (when-let* ((face (alist-get state cj/buffer-status-faces))
+              (fg (face-attribute face :foreground nil t)))
+    (and (stringp fg) fg)))
 
 ;; --------------------------- Media File Extensions ---------------------------