From f66543a308c2e420ef3b4fc4b5033bec8d77dbfe Mon Sep 17 00:00:00 2001
From: Javier Sagredo <javier.sagredo@iohk.io>
Date: Thu, 7 May 2026 00:08:40 +0200
Subject: [PATCH] Add two Emacs editor-link schemes

emacs://: a freeform URL the user maps to emacsclient via xdg-mime.
emacs-org://: the canonical org-protocol://open-source URL handler
that ships with Emacs once (require 'org-protocol) is loaded.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
---
 README.md        |  6 +++---
 data/viewer.html |  2 ++
 data/viewer.js   | 14 ++++++++++++++
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/README.md b/README.md
index ae4d0e9..863c42f 100644
--- a/README.md
+++ b/README.md
@@ -279,13 +279,13 @@ The side panel has an `Editor link` block at the top with two settings
 
 | Setting | What it does |
 |---|---|
-| **Editor** | Picks a URL scheme — VS Code, VS Code Insiders, Cursor, IntelliJ family, TextMate (`txmt://`), or plain `file://`. Set it to *off* to keep `Defined at` as plain text. |
+| **Editor** | Picks a URL scheme — VS Code, VS Code Insiders, Cursor, IntelliJ family, TextMate (`txmt://`), Emacs (`emacs://` or `org-protocol://`), or plain `file://`. Set it to *off* to keep `Defined at` as plain text. |
 | **Source root override** | Absolute prefix prepended to relative paths when no per-package root is known. Usually leave blank — `classgraph-view` infers roots from `--input` (see below). |
 
 Once an editor is chosen, every `Defined at` line in the panel becomes
 a clickable link that opens the file at the right line in your editor.
-Schemes that take a column (`vscode`, `cursor`, `txmt`) get one;
-`idea` and `file` ignore it.
+Schemes that take a column (`vscode`, `cursor`, `txmt`, `emacs`) get
+one; `idea`, `emacs-org`, and `file` ignore it.
 
 **Source roots are inferred automatically.** The plugin records source
 paths as GHC saw them (usually relative to each package's source dir),
diff --git a/data/viewer.html b/data/viewer.html
index c84f951..e83979d 100644
--- a/data/viewer.html
+++ b/data/viewer.html
@@ -85,6 +85,8 @@
           <option value="cursor">Cursor</option>
           <option value="idea">IntelliJ / IDEA family</option>
           <option value="txmt">TextMate (txmt://)</option>
+          <option value="emacs">Emacs (emacs://)</option>
+          <option value="emacs-org">Emacs (org-protocol)</option>
           <option value="file">file:// (no line jump)</option>
         </select>
       </div>
diff --git a/data/viewer.js b/data/viewer.js
index 01e13a1..757e9b0 100644
--- a/data/viewer.js
+++ b/data/viewer.js
@@ -1410,6 +1410,20 @@
         return `idea://open?file=${encodeURIComponent(abs)}&line=${line}`;
       case 'txmt':
         return `txmt://open?url=file://${enc}&line=${line}&column=${col || 1}`;
+      case 'emacs':
+        // Same query-string shape as `idea`, intentionally — user-side
+        // handlers (xdg-mime / a small wrapper that calls emacsclient
+        // +LINE:COL FILE) are easy to write against this layout. See
+        // the README for an example.
+        return `emacs://open?file=${encodeURIComponent(abs)}` +
+               `&line=${line}&column=${col || 1}`;
+      case 'emacs-org':
+        // Emacs's own org-protocol://open-source URL handler. Requires
+        // (require 'org-protocol) plus (server-start) on the user's
+        // side — the canonical Emacs-internal way.
+        return `org-protocol://open-source?url=` +
+               encodeURIComponent('file://' + (enc.startsWith('/') ? enc : '/' + enc)) +
+               `&line=${line}`;
       case 'file':
         return `file://${enc.startsWith('/') ? '' : '/'}${enc}`;
       default:
-- 
2.54.0