refactor(term): extract eat-config.el from term-config.el

Move the eat use-package, the F12/C-; keymap wiring, and the F12 dock-and-remember toggle out of term-config.el into a dedicated eat-config.el. term-config.el keeps ghostel (ai-term's backend) and requires eat-config for cj/term-toggle and cj/turn-off-chrome-for-term. Pure relocation, no behavior change. First step toward consolidating on EAT and retiring ghostel. The toggle tests now require eat-config.

1 files changed, 213 insertions, 0 deletions

diff --git a/modules/eat-config.el b/modules/eat-config.el
new file mode 100644
index 000000000..9a52dabfd
--- /dev/null
+++ b/modules/eat-config.el
@@ -0,0 +1,213 @@
+;;; eat-config.el --- EAT terminal and the F12 toggle -*- lexical-binding: t; coding: utf-8; -*-
+
+;;; Commentary:
+;;
+;; EAT (Emulate A Terminal, pure elisp) is the F12 terminal.  Because EAT renders
+;; entirely in elisp, its whole palette is real Emacs faces, so it themes from
+;; the theme.  This module owns the eat package configuration, the keymap wiring
+;; that lets F12 and C-; reach Emacs from inside a terminal, and the F12
+;; dock-and-remember toggle.
+;;
+;; The toggle reuses the geometry-preservation pattern from cj-window-toggle-lib:
+;; capture direction + body size at toggle-off, replay them via a custom display
+;; action using frame-edge directions and body-relative sizes, so the docked
+;; terminal returns at the same size and the result is divider-independent.
+
+;;; Code:
+
+(require 'cj-window-geometry-lib)
+(require 'cj-window-toggle-lib)
+
+(declare-function eat "eat" (&optional program arg))
+(defvar eat-buffer-name)
+(defvar eat-mode-map)
+(defvar eat-semi-char-mode-map)
+(defvar cj/custom-keymap)
+
+(defun cj/turn-off-chrome-for-term ()
+  "Turn off line numbers and hl-line in a terminal buffer."
+  (hl-line-mode -1)
+  (display-line-numbers-mode -1))
+
+;; ------------------------------- eat package ---------------------------------
+
+(use-package eat
+  :ensure t
+  :commands (eat)
+  :hook (eat-mode . cj/turn-off-chrome-for-term)
+  :custom
+  ;; Close the EAT buffer when its shell exits.
+  (eat-kill-buffer-on-exit t)
+  :config
+  ;; F12 and C-; must reach Emacs from inside EAT.  In semi-char mode (EAT's
+  ;; default) EAT forwards unbound keys to the terminal -- a letter runs
+  ;; `eat-self-input' -- so bind these explicitly or they never reach Emacs:
+  ;; F12 toggles the terminal window, C-; opens the global prefix map.
+  (keymap-set eat-semi-char-mode-map "<f12>" #'cj/term-toggle)
+  (keymap-set eat-semi-char-mode-map "C-;" cj/custom-keymap)
+  (keymap-set eat-mode-map "<f12>" #'cj/term-toggle)
+  (keymap-set eat-mode-map "C-;" cj/custom-keymap))
+
+;; ----------------------- F12 toggle (custom) -----------------------
+;;
+;; Mirrors the geometry-preservation pattern shared with ai-term.el: capture
+;; direction + body size at toggle-off, replay them via a custom display action
+;; using frame-edge directions and body-relative sizes so the result is
+;; divider-independent and layout-stable.  Manages the EAT terminal only;
+;; ai-term.el's ghostel agent buffers are separate (M-SPC).
+
+(defcustom cj/term-toggle-window-height 0.7
+  "Default fraction of frame height for the F12 terminal window.
+Used as the size fallback when F12 docks the terminal as a bottom split."
+  :type 'number
+  :group 'term)
+
+(defcustom cj/term-toggle-window-width 0.5
+  "Default fraction of frame width for the F12 terminal window.
+Used as the size fallback when F12 docks the terminal as a right-side
+column (see `cj/--term-toggle-default-direction')."
+  :type 'number
+  :group 'term)
+
+(defun cj/--term-toggle-default-direction ()
+  "Return the default dock direction for the F12 terminal: `right' or `below'.
+Docks as a right-side column only when a side-by-side split would leave
+both panes at least `cj/window-dock-min-columns' wide (the terminal's
+share is `cj/term-toggle-window-width'); otherwise stacks below.  See
+`cj/preferred-dock-direction'."
+  (cj/preferred-dock-direction (frame-width) cj/term-toggle-window-width))
+
+(defun cj/--term-toggle-default-size (direction)
+  "Return the default size fraction paired with DIRECTION for the F12 terminal.
+`cj/term-toggle-window-width' for `right', `cj/term-toggle-window-height'
+otherwise."
+  (if (eq direction 'right)
+      cj/term-toggle-window-width
+    cj/term-toggle-window-height))
+
+(defvar cj/--term-toggle-last-direction nil
+  "Last user-chosen direction for the F12 terminal display.
+Symbol: right, left, or below.  `above' is never stored.  nil means use the
+default `below' for F12's traditional bottom split.")
+
+(defvar cj/--term-toggle-last-size nil
+  "Last user-chosen size for the F12 terminal display.
+Positive integer: body-cols (right/left) or total-lines (below/above) -- see
+`cj/window-replay-size' for why the vertical axis uses total, not body.
+nil means fall back to `cj/term-toggle-window-height' as a fraction.")
+
+(defun cj/--term-toggle-buffer-p (buffer)
+  "Return non-nil when BUFFER is the EAT terminal F12 should manage.
+
+Qualifies when BUFFER is alive and has `eat-mode' (or its name starts with the
+EAT buffer-name prefix).  ai-term's ghostel agent buffers never match -- they
+are managed separately via M-SPC, not F12."
+  (and (bufferp buffer)
+       (buffer-live-p buffer)
+       (with-current-buffer buffer
+         (or (eq major-mode 'eat-mode)
+             (string-prefix-p (or (bound-and-true-p eat-buffer-name)
+                                  "*eat*")
+                              (buffer-name buffer))))))
+
+(defun cj/--term-toggle-buffers ()
+  "Return live F12-managed terminal buffers in `buffer-list' (MRU) order."
+  (seq-filter #'cj/--term-toggle-buffer-p (buffer-list)))
+
+(defun cj/--term-toggle-displayed-window (&optional frame)
+  "Return a window in FRAME currently displaying an F12 terminal buffer, or nil.
+FRAME defaults to the selected frame.  Minibuffer is excluded."
+  (seq-find (lambda (w)
+              (cj/--term-toggle-buffer-p (window-buffer w)))
+            (window-list (or frame (selected-frame)) 'never)))
+
+(defun cj/--term-toggle-capture-state (window)
+  "Capture WINDOW's direction + body size into module-level state.
+The default direction (used when WINDOW fills its frame) is the
+column-rule choice from `cj/--term-toggle-default-direction'."
+  (cj/window-toggle-capture-state
+   window (cj/--term-toggle-default-direction)
+   'cj/--term-toggle-last-direction
+   'cj/--term-toggle-last-size
+   '(right below left)))
+
+(defun cj/--term-toggle-display-saved (buffer alist)
+  "Display-buffer action: split per saved direction and body size.
+Delegates to `cj/window-toggle-display-saved' against the F12 state vars,
+falling back to the column-rule default direction
+\(`cj/--term-toggle-default-direction') and its paired size."
+  (let ((dir (cj/--term-toggle-default-direction)))
+    (cj/window-toggle-display-saved
+     buffer alist
+     'cj/--term-toggle-last-direction dir
+     'cj/--term-toggle-last-size (cj/--term-toggle-default-size dir))))
+
+(defun cj/--term-toggle-display-rule-list ()
+  "Return the `display-buffer-alist' entry list installed by F12.
+Routes any terminal buffer satisfying `cj/--term-toggle-buffer-p' through
+reuse-window then the saved-geometry action.  Excludes agent buffers."
+  '(((lambda (buffer-or-name _)
+       (cj/--term-toggle-buffer-p (get-buffer buffer-or-name)))
+     (display-buffer-reuse-window
+      cj/--term-toggle-display-saved)
+     (inhibit-same-window . t))))
+
+(dolist (entry (cj/--term-toggle-display-rule-list))
+  (add-to-list 'display-buffer-alist entry))
+
+(defun cj/--term-toggle-dispatch ()
+  "Compute the F12 (`cj/term-toggle') action without performing it.
+
+Returns one of:
+- (toggle-off . WINDOW)        -- terminal displayed in WINDOW; hide it.
+- (show-recent . BUFFER)       -- terminal alive but not shown; redisplay.
+- (create-new)                 -- no terminal buffer alive; create one."
+  (let ((win (cj/--term-toggle-displayed-window)))
+    (cond
+     (win (cons 'toggle-off win))
+     (t
+      (let ((buffers (cj/--term-toggle-buffers)))
+        (cond
+         (buffers (cons 'show-recent (car buffers)))
+         (t '(create-new))))))))
+
+(defun cj/term-toggle ()
+  "Toggle the EAT terminal buffer.
+
+- If the EAT terminal is displayed in this frame, capture its geometry and
+  delete its window (toggle off).  Falls back to burying when it is the only
+  window in the frame.
+- Otherwise, if the EAT terminal buffer is alive, display it via the
+  saved-geometry action.
+- Otherwise, create a new EAT terminal, displaying it through the same
+  saved-geometry action.
+
+ai-term's ghostel agent buffers are managed separately via M-SPC, not F12."
+  (interactive)
+  (pcase (cj/--term-toggle-dispatch)
+    (`(toggle-off . ,win)
+     (cj/--term-toggle-capture-state win)
+     (if (one-window-p)
+         (bury-buffer (window-buffer win))
+       (delete-window win))
+     nil)
+    (`(show-recent . ,buf)
+     (display-buffer buf)
+     (let ((w (get-buffer-window buf)))
+       (when w (select-window w)))
+     buf)
+    (`(create-new)
+     ;; Create the EAT buffer without stealing the layout, then display it
+     ;; through the saved-geometry dock rule (same path as show-recent).
+     (save-window-excursion (eat))
+     (let ((buf (get-buffer (or (bound-and-true-p eat-buffer-name) "*eat*"))))
+       (when buf
+         (display-buffer buf)
+         (let ((w (get-buffer-window buf)))
+           (when w (select-window w))))
+       buf))))
+
+(keymap-global-set "<f12>" #'cj/term-toggle)
+
+(provide 'eat-config)
+;;; eat-config.el ends here