From 1172f5cb3d7f70b08e6c1cb9ad23e9680c4c5fe1 Mon Sep 17 00:00:00 2001
From: Robert Krahn <robert.krahn@gmail.com>
Date: Sun, 26 May 2013 18:55:38 -0700
Subject: [PATCH] emacs: adding mark-ring

---
 lib/ace/keyboard/emacs.js | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/lib/ace/keyboard/emacs.js b/lib/ace/keyboard/emacs.js
index 71d4d0b7..f0df7d87 100644
--- a/lib/ace/keyboard/emacs.js
+++ b/lib/ace/keyboard/emacs.js
@@ -96,15 +96,31 @@ exports.handler.attach = function(editor) {
     editor.session.$useEmacsStyleLineStart = true;
 
     editor.session.$emacsMark = null;
+    editor.session.$emacsMarkRing = editor.session.$emacsMarkRing || [];
 
     editor.emacsMarkMode = function() {
         return this.session.$emacsMark;
     }
 
     editor.setEmacsMarkMode = function(p) {
+        var prevMark = this.session.$emacsMark;
+        if (prevMark)
+            this.session.$emacsMarkRing.push(prevMark);
         this.session.$emacsMark = p;
     }
 
+    editor.pushEmacsMark = function(p, activate) {
+        var prevMark = this.session.$emacsMark;
+        if (prevMark)
+            this.session.$emacsMarkRing.push(prevMark);
+        if (activate) this.session.$emacsMark = p;
+        else this.session.$emacsMarkRing.push(p);
+    }
+
+    editor.getLastEmacsMark = function(p) {
+        return this.session.$emacsMark || this.session.$emacsMarkRing.reverse()[0];
+    }
+
     editor.on("click", $resetMarkMode);
     editor.on("changeSession", $kbSessionChange);
     editor.renderer.screenToTextCoordinates = screenToTextBlockCoordinates;
@@ -141,6 +157,8 @@ var $kbSessionChange = function(e) {
 
     if (!e.session.hasOwnProperty('$emacsMark'))
         e.session.$emacsMark = null;
+    if (!e.session.hasOwnProperty('$emacsMarkRing'))
+        e.session.$emacsMarkRing = [];
 }
 
 var $resetMarkMode = function(e) {
@@ -168,6 +186,10 @@ exports.handler.onCopy = function(e, editor) {
     delete editor.$handlesEmacsOnCopy;
 }
 
+exports.handler.onPaste = function(e, editor) {
+    editor.pushEmacsMark(editor.getCursorPosition());
+}
+
 exports.handler.bindKey = function(key, command) {
     if (!key)
         return;