灵感来自org-bullets，另外参考了Adding keymaps to src blocks via org-font-lock-hook 搜索了下论坛好像没人发过？
(use-package org
:defer t
:config
(defvar org-level-click-map '(keymap (mouse-1 . org-cycle))
"")
(defun org-add-keymap-to-level (limit)
(let ((case-fold-search t))
(while (re-search-forward org-heading-regexp limit t)
(put-text-property
(match-beginning 0)
(match-end 0)
'keymap
org-level-click-map))))
(add-hook 'org-font-lock-hook #'org-add-keymap-to-level))
效果如图：
