Edit notebook cells in popout buffer ala org-mode

Using C-c', users can create a temporary buffer running an appropriate
mode to edit the contents of a notebook cell. This functionality is
intentionally very similar to what org-mode provides for editing blocks
of code or other.

lisp/ein-cell-edit.el

@@ -0,0 +1,147 @@
+;;; ein-cell-edit.el --- Notebook cell editing
+
+;; Copyright (C) 2016 John M. Miller
+
+;; Author: John Miller <millejoh at mac.com>
+
+;; This file is NOT part of GNU Emacs.
+
+;; ein-cell-edit.el is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; ein-cell-edit.el is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with ein-worksheet.el.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This code inspired by borrowing from org-src.el.
+
+;;; Code:
+
+(defvar ein:src--cell nil)
+(defvar ein:src--ws nil)
+(defvar ein:src--allow-write-back t)
+
+(defvar ein:edit-cell-mode-map
+  (let ((map (make-sparse-keymap)))
+    (define-key map "\C-c'" 'ein:edit-cell-exit)
+    (define-key map "\C-c\C-k" 'ein:edit-cell-abort)
+    (define-key map "\C-x\C-s" 'ein:edit-cell-save)
+    map))
+
+(define-minor-mode ein:edit-cell-mode
+  "Minor mode for language major mode buffers generated by EIN.
+  \\<org-mode-map>
+  This minor mode is turned on when editing a source code snippet with \\[org-edit-special]
+
+  \\{ein:edit-cell-mode-map}
+
+  See also `org-src-mode-hook'."
+  nil " EinCell" nil
+  (set (make-local-variable 'header-line-format)
+       (substitute-command-keys
+        "Edit, then exit with \\[ein:edit-cell-exit] or abort with \
+  \\[ein:edit-cell-abort]"))
+  ;; Possibly activate various auto-save features (for the edit buffer
+  ;; or the source buffer).
+  ;; (when org-edit-src-turn-on-auto-save
+  ;;   (setq buffer-auto-save-file-name
+  ;;   (concat (make-temp-name "org-src-")
+  ;;    (format-time-string "-%Y-%d-%m")
+  ;;    ".txt")))
+  ;; (unless (or org-src--auto-save-timer (zerop org-edit-src-auto-save-idle-delay))
+  ;;   (setq org-src--auto-save-timer
+  ;;         (run-with-idle-timer
+  ;;          org-edit-src-auto-save-idle-delay t
+  ;;          (lambda ()
+  ;;            (save-excursion
+  ;;              (let (edit-flag)
+  ;;                (dolist (b (buffer-list))
+  ;;                  (with-current-buffer b
+  ;;                    (when (org-src-edit-buffer-p)
+  ;;                      (unless edit-flag (setq edit-flag t))
+  ;;                      (when (buffer-modified-p) (org-edit-src-save)))))
+  ;;                (unless edit-flag
+  ;;                  (cancel-timer org-src--auto-save-timer)
+  ;;                  (setq org-src--auto-save-timer nil))))))))
+  )
+
+(defun ein:cell-configure-edit-buffer ()
+  (when (org-bound-and-true-p org-src--from-org-mode)
+    (org-add-hook 'kill-buffer-hook #'org-src--remove-overlay nil 'local)
+    (if (org-bound-and-true-p org-src--allow-write-back)
+        (progn
+          (setq buffer-offer-save t)
+          (setq buffer-file-name
+                (concat (buffer-file-name (marker-buffer org-src--beg-marker))
+                        "[" (buffer-name) "]"))
+          (setq write-contents-functions '(ein:edit-cell-save)))
+      (setq buffer-read-only t))))
+
+(defun ein:edit-cell-save ()
+  (interactive)
+  ;;(unless (ein:cell-edit-buffer-p) (user-error "Not in a sub-editing buffer"))
+  (set-buffer-modified-p nil)
+  (let ((edited-code (buffer-string)
+                     ;;(org-src--contents-for-write-back)
+                     )
+        ;; (beg org-src--beg-marker)
+        ;; (end org-src--end-marker)
+        ;; (overlay org-src--overlay)
+        )
+    (setf (slot-value ein:src--cell 'input) edited-code)
+    (ein:worksheet-render ein:src--ws)))
+
+(defun ein:edit-cell-exit ()
+  (interactive)
+  ;;(unless (org-src-edit-buffer-p) (error "Not in a sub-editing buffer"))
+  (let ((edit-buffer (current-buffer))
+        (ws ein:src--ws))
+    (switch-to-buffer (ein:worksheet-buffer ws))
+    (when ein:src--allow-write-back
+      (ein:edit-cell-save))
+    (kill-buffer edit-buffer)
+    ;; FIXME: put point at an appropriate location as org does?
+    ))
+
+(defun ein:edit-cell-abort ()
+  (interactive)
+  (let (ein:src--allow-write-back) (ein:edit-cell-exit)))
+
+(defun ein:construct-cell-edit-buffer-name (bufname cell-type)
+  (concat "*EIN Src " bufname "[ " cell-type " ]*" ))
+
+(defun ein:edit-cell-contents ()
+  (interactive)
+  (let* ((cell (or (ein:get-cell-at-point)
+                   (error "Must be called from inside an EIN worksheet cell.")))
+         (ws ein:%worksheet%)
+         (contents (slot-value cell 'input))
+         (type (slot-value cell 'cell-type))
+         (name (ein:construct-cell-edit-buffer-name (buffer-name) type))
+         (buffer (generate-new-buffer-name name)))
+    (switch-to-buffer-other-window buffer)
+    (insert contents)
+    (remove-text-properties (point-min) (point-max)
+                            '(display nil invisible nil intangible nil))
+    (set-buffer-modified-p nil)
+    (setq buffer-file-name nil)
+    (condition-case e
+        (ein:case-equal type
+          (("markdown") (markdown-mode))
+          (("code") (python-mode)))
+      (error (message "Language mode `%s' fails with: %S"
+                      type (nth 1 e))))
+    (set (make-local-variable 'ein:src--cell) cell)
+    (set (make-local-variable 'ein:src--ws) ws)
+    (set (make-local-variable 'ein:src--allow-write-back) t)
+    (ein:edit-cell-mode)))
+
+(provide 'ein-cell-edit)

lisp/ein-notebook.el

@@ -44,6 +44,7 @@
 (require 'ein-kernel)
 (require 'ein-kernelinfo)
 (require 'ein-cell)
+(require 'ein-cell-edit)
 (require 'ein-cell-output)
 (require 'ein-worksheet)
 (require 'ein-scratchsheet)
@@ -1385,6 +1386,7 @@ This hook is run regardless the actual major mode used."
 (defvar ein:notebook-mode-map (make-sparse-keymap))
 
 (let ((map ein:notebook-mode-map))
+  (define-key map "\C-c'" 'ein:edit-cell-contents)
   (define-key map "\C-cS" 'ein:worksheet-toggle-slideshow-view)
   (define-key map "\C-c\C-c" 'ein:worksheet-execute-cell)
   (define-key map (kbd "M-RET") 'ein:worksheet-execute-cell-and-goto-next)

lisp/ein-worksheet.el

@@ -25,7 +25,6 @@
 
 ;;; Code:
 
-
 (eval-when-compile (require 'cl))
 (require 'eieio)
 (require 'ewoc)

lisp/ob-ein.el

@@ -1,6 +1,6 @@
 ;;; ob-ein.el --- org-babel functions for template evaluation
 
-;; Copyright (C) John M. miller (
+;; Copyright (C) John M. Miller
 
 ;; Author: John M. Miller <millejoh at mac.com>
 ;;
@@ -29,7 +29,6 @@
 ;;; Code:
 (require 'ob)
 (require 'ob-python)
-;; possibly require modes required for your language
 (require 'cl)
 (require 'ein-notebook)
 (require 'ein-shared-output)