(feat): Protect region targeted by org-roam-insert (#974)

Co-authored-by: Jethro Kuan <jethrokuan95@gmail.com>

CHANGELOG.md

@@ -1,5 +1,15 @@
 # Changelog
 
+## 1.2.2 (TBD)
+
+### Breaking Changes
+
+### Features
+
+-[#974](https://github.com/org-roam/org-roam/pull/974) Protect region targeted by `org-roam-insert`
+
+### Bugfixes
+
 ## 1.2.1 (27-07-2020)
 
 This release consisted of a big deal of refactoring and bug fixes. Notably, we fixed several catastrophic failures on db builds with bad setups (#854), and modularized tag and title extractions.

org-roam-capture.el

@@ -31,6 +31,7 @@
 ;;; Code:
 ;;;; Library Requires
 (require 'org-capture)
+(require 'org-roam-macs)
 (require 'dash)
 (require 's)
 (require 'cl-lib)
@@ -320,8 +321,14 @@ the capture)."
 
 (defun org-roam-capture--finalize ()
   "Finalize the `org-roam-capture' process."
+  (let* ((finalize (org-roam-capture--get :finalize))
+         ;; In case any regions were shielded before, unshield them
+         (region (when-let ((region (org-roam-capture--get :region)))
+                   (org-roam-unshield-region (car region) (cdr region))))
+         (beg (car region))
+         (end (cdr region)))
     (unless org-note-abort
-    (pcase (org-roam-capture--get :finalize)
+      (pcase finalize
         ('find-file
          (when-let ((file-path (org-roam-capture--get :file-path)))
            (org-roam--find-file file-path)
@@ -330,7 +337,7 @@ the capture)."
          (when-let* ((mkr (org-roam-capture--get :insert-at))
                      (buf (marker-buffer mkr)))
            (with-current-buffer buf
-           (when-let ((region (org-roam-capture--get :region))) ;; Remove previously selected text.
+             (when region
                (delete-region (car region) (cdr region)))
              (let ((path (org-roam-capture--get :file-path))
                    (desc (org-roam-capture--get :link-description)))
@@ -338,8 +345,11 @@ the capture)."
                    (insert (org-roam--format-link path desc))
                  (org-with-point-at mkr
                    (insert (org-roam--format-link path desc))))))))))
+    (when region
+      (set-marker beg nil)
+      (set-marker end nil))
     (org-roam-capture--save-file-maybe)
-  (remove-hook 'org-capture-after-finalize-hook #'org-roam-capture--finalize))
+    (remove-hook 'org-capture-after-finalize-hook #'org-roam-capture--finalize)))
 
 (defun org-roam-capture--install-finalize ()
   "Install `org-roam-capture--finalize' if the capture is an Org-roam capture."

org-roam-macs.el

@@ -77,6 +77,28 @@ to look.
        (s-replace "\\" "\\\\")
        (s-replace "\"" "\\\"")))
 
+;;; Shielding regions
+(defun org-roam-shield-region (beg end)
+  "Shield REGION against modifications.
+REGION must be a cons-cell containing the marker to the region
+beginning and maximum values."
+  (when (and beg end)
+    (add-text-properties beg end
+                           '(font-lock-face org-roam-link-shielded
+                                            read-only t)
+                           (marker-buffer beg))
+    (cons beg end)))
+
+(defun org-roam-unshield-region (beg end)
+  "Unshield the shielded REGION."
+  (when (and beg end)
+    (let ((inhibit-read-only t))
+      (remove-text-properties beg end
+                              '(font-lock-face org-roam-link-shielded
+                                               read-only t)
+                              (marker-buffer beg)))
+    (cons beg end)))
+
 (provide 'org-roam-macs)
 
 ;;; org-roam-macs.el ends here

org-roam.el

@@ -960,6 +960,13 @@ Return nil if the file does not exist."
 This face is used for links without a destination."
   :group 'org-roam-faces)
 
+(defface org-roam-link-shielded
+  '((t :inherit (warning org-link)))
+  "Face for Org-roam links that are shielded.
+This face is used on the region target by `org-roam-insertion'
+during an `org-roam-capture'."
+  :group 'org-roam-faces)
+
 ;;;; org-roam-backlinks-mode
 (define-minor-mode org-roam-backlinks-mode
   "Minor mode for the `org-roam-buffer'.
@@ -1420,11 +1427,16 @@ If DESCRIPTION is provided, use this as the link label.  See
 `org-roam--get-title-path-completions' for details."
   (interactive "P")
   (unless org-roam-mode (org-roam-mode))
-  (let* ((region (and (region-active-p)
+  ;; Deactivate the mark on quit since `atomic-change-group' prevents it
-                      ;; following may lose active region, so save it
+  (unwind-protect
-                      (cons (region-beginning) (region-end))))
+      ;; Group functions together to avoid inconsistent state on quit
-         (region-text (when region
+      (atomic-change-group
-                        (buffer-substring-no-properties (car region) (cdr region))))
+        (let* (region-text
+               beg end
+               (_ (when (region-active-p)
+                    (setq beg (set-marker (make-marker) (region-beginning)))
+                    (setq end (set-marker (make-marker) (region-end)))
+                    (setq region-text (buffer-substring-no-properties beg end))))
                (completions (--> (or completions
                                      (org-roam--get-title-path-completions))
                                  (if filter-fn
@@ -1440,22 +1452,25 @@ If DESCRIPTION is provided, use this as the link label.  See
                (link-description (org-roam--format-link-title (if lowercase
                                                                   (downcase description)
                                                                 description))))
-    (if (and target-file-path
+          (cond ((and target-file-path
                       (file-exists-p target-file-path))
-        (progn
+                 (when region-text
-          (when region ;; Remove previously selected text.
+                   (delete-region beg end)
-            (delete-region (car region) (cdr region)))
+                   (set-marker beg nil)
+                   (set-marker end nil))
                  (insert (org-roam--format-link target-file-path link-description)))
+                (t
                  (let ((org-roam-capture--info `((title . ,title-with-tags)
                                                  (slug . ,(funcall org-roam-title-to-slug-function title-with-tags))))
                        (org-roam-capture--context 'title))
-        (setq org-roam-capture-additional-template-props (list :region region
+                   (setq org-roam-capture-additional-template-props (list :region (org-roam-shield-region beg end)
                                                                           :insert-at (point-marker)
                                                                           :link-description link-description
                                                                           :finalize 'insert-link))
                    (org-roam--with-template-error 'org-roam-capture-templates
-          (org-roam-capture--capture))))
+                     (org-roam-capture--capture)))))
           res))
+    (deactivate-mark)))
 
 ;;;###autoload
 (defun org-roam-insert-immediate (arg &rest args)