(change): open file links in org-roam buffer in `org-roam-last-window` (#108)

Addresses #30 , thanks @l3kn

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## 0.1.2 (TBD)
 
+### Changes
+
+* [#108][gh-108] Locally overwrite the link following behaviour in the org-roam-buffer to open files in the same window `org-roam` was called from
+
 ### Breaking Changes
 * [#103][gh-103] Change `org-roam-file-format` to a function: `org-roam-file-name-function` to allow more flexible file name customizaton. Also changes `org-roam-use-timestamp-as-filename` to `org-roam-filename-noconfirm` to better describe what it does.
 
@@ -53,6 +57,7 @@ Mostly a documentation/cleanup release.
 [gh-98]: https://github.com/jethrokuan/org-roam/pull/98
 [gh-103]: https://github.com/jethrokuan/org-roam/pull/103
 [gh-105]: https://github.com/jethrokuan/org-roam/pull/105
+[gh-108]: https://github.com/jethrokuan/org-roam/pull/108
 
  # Local Variables:
  # eval: (auto-fill-mode -1)

org-roam.el

@@ -152,6 +152,9 @@ If called interactively, then PARENTS is non-nil."
 (defvar org-roam-current-file nil
   "Currently displayed file in `org-roam' buffer.")
 
+(defvar org-roam-last-window nil
+  "Last window `org-roam' was called from.")
+
 ;;; Utilities
 (defun org-roam--ensure-cache-built ()
   "Ensures that org-roam cache is built."
@@ -391,11 +394,25 @@ This is equivalent to removing the node from the graph."
     (org-roam--new-file-named (format-time-string "%Y-%m-%d" time))))
 
 ;;; Org-roam buffer updates
+
+(defun org-roam--find-file (file)
+  "Open FILE in the window `org-roam' was called from."
+  (if (and org-roam-last-window (window-valid-p org-roam-last-window))
+      (progn (with-selected-window org-roam-last-window
+               (find-file file))
+             (select-window org-roam-last-window))
+    (find-file file)))
+
 (defun org-roam-update (file-path)
   "Show the backlinks for given org file for file at `FILE-PATH'."
   (org-roam--ensure-cache-built)
   (let ((buffer-title (org-roam--get-title-or-slug file-path)))
     (with-current-buffer org-roam-buffer
+      ;; Locally overwrite the file opening function to re-use the
+      ;; last window org-roam was called from
+      (setq-local
+       org-link-frame-setup
+       (cons '(file . org-roam--find-file) org-link-frame-setup))
       (let ((inhibit-read-only t))
         (erase-buffer)
         (when (not (eq major-mode 'org-mode))
@@ -458,6 +475,7 @@ Valid states are 'visible, 'exists and 'none."
 (defun org-roam ()
   "Pops up the window `org-roam-buffer' accordingly."
   (interactive)
+  (setq org-roam-last-window (get-buffer-window))
   (pcase (org-roam--current-visibility)
     ('visible (delete-window (get-buffer-window org-roam-buffer)))
     ('exists (org-roam--setup-buffer))