code: function _activeEditorChange(e, current) {
          if (current) {
              var $container = current.$el.parent().parent(),
                  pane = _getPaneFromElement($container);
  
              if (pane) {
                  // Editor is a full editor
                  if (pane.id !== _activePaneId) {
                      // we just need to set the active pane in this case
                      //  it will dispatch the currentFileChange message as well
                      //  as dispatching other events when the active pane changes
                      setActivePaneId(pane.id);
                  }
              } else {
                  // Editor is an inline editor, find the parent pane
                  var parents = $container.parents(".view-pane");
                  if (parents.length === 1) {
                      $container = $(parents[0]);
                      pane = _getPaneFromElement($container);
                      if (pane) {
                          if (pane.id !== _activePaneId) {
                              // activate the pane which will put focus in the pane's doc
                              setActivePaneId(pane.id);
                              // reset the focus to the inline editor
                              current.focus();
                          }
                      }
                  }
              }
          }
      }
docs: EditorManager.activeEditorChange handler
  This event is triggered when an visible editor gains focus
  Therefore we need to Activate the pane that the active editor belongs to
  @private
  @param {!jQuery.Event} e - jQuery Event object
  @param {Editor=} current - editor being made the current editor