ctrl-c copies if you aren't on a mac (#34)

* only bind ctrl-c leave insert mode for mac

* better

Author: jwkvam

package.json

@@ -1,6 +1,6 @@
 {
   "name": "jupyterlab_vim",
-  "version": "0.5.0",
+  "version": "0.6.0-dev",
   "description": "Code cell vim bindings",
   "author": "Jacques Kvam",
   "main": "lib/index.js",

src/index.ts

@@ -26,6 +26,11 @@ import {
 
 import '../style/index.css';
 
+/**
+ * A boolean indicating whether the platform is Mac.
+ */
+const IS_MAC = !!navigator.platform.match(/Mac/i);
+
 /**
  * Initialization data for the jupyterlab_vim extension.
  */
@@ -57,7 +62,9 @@ class VimCell {
             let extraKeys = editor.getOption('extraKeys') || {};
 
             extraKeys['Esc'] = CodeMirror.prototype.leaveInsertMode;
-            extraKeys['Ctrl-C'] = CodeMirror.prototype.leaveInsertMode;
+            if (!IS_MAC) {
+                extraKeys['Ctrl-C'] = false;
+            }
 
             CodeMirror.prototype.save = () => {
                 commands.execute('docmanager:save');