如何让指定区域内单击鼠标左键的时候显示颜色

Emacs-general
1

如题,比如在[(100,100),(200,200)]这个正方形区域内,当鼠标位于该区域内包括边界,单击的同时,让这个区域显示一个前景色,点击结束颜色消失

(setq column-region '(100 . 100))
(setq row-region '(200 . 200))
(defun show-color ()
  (interactive)
  (let (
		(mouse-x-pos (car (cdr (mouse-pixel-position))))
		(mouse-y-pos (cdr (cdr (mouse-pixel-position))))
		)
	(if (and
		 (>= mouse-x-pos (car column-region))
		 (<= mouse-x-pos (cdr column-region))
		 (>= mouse-y-pos (car row-region))
		 (<= mouse-y-pos (cdr row-region))
		 )
		
		(message "column : %s\nrow : %s" mouse-x-pos mouse-y-pos)
	  )
	)
  )