focus caret at line

src/static/js/ace2_inner.js

@@ -682,6 +682,7 @@ function Ace2Inner() {
   editorInfo.ace_doReturnKey = doReturnKey;
   editorInfo.ace_isBlockElement = isBlockElement;
   editorInfo.ace_getLineListType = getLineListType;
+  editorInfo.ace_setSelection = setSelection;
 
   editorInfo.ace_callWithAce = function (fn, callStack, normalize) {
     let wrapper = function () {

src/static/js/pad_editor.js

@@ -60,6 +60,24 @@ const padeditor = (function () {
                       .find('#outerdocbody').parent();
                   $outerdoc.css({top: `${offsetTop}px`}); // Chrome
                   $outerdocHTML.animate({scrollTop: offsetTop}); // needed for FF
+                  const node = line[0];
+                  self.ace.callWithAce((ace) => {
+                    const selection = {
+                      startPoint: {
+                        index: 0,
+                        focusAtStart: true,
+                        maxIndex: 1,
+                        node,
+                      },
+                      endPoint: {
+                        index: 0,
+                        focusAtStart: true,
+                        maxIndex: 1,
+                        node,
+                      },
+                    };
+                    ace.ace_setSelection(selection);
+                  });
                 }
               }
             }