Function handleKeyEvent_

static/js/codemirror/keymap/vim.js:2504–2520

(cm, key, modifier)

       */
      // TODO: Figure out a way to catch capslock.
      function handleKeyEvent_(cm, key, modifier) {
        if (isUpperCase(key)) {
          // Convert to lower case if shift is not the modifier since the key
          // we get from CodeMirror is always upper case.
          if (modifier == 'Shift') {
            modifier = null;
          }
          else {
            key = key.toLowerCase();
          }
        }
        if (modifier) {
          // Vim will parse modifier+key combination as a single key.
          key = modifier + '-' + key;
        }
        vim.handleKey(cm, key);
      }

      // Closure to bind CodeMirror, key, modifier.
      function keyMapper(key, modifier) {