Binding `S-mouse-1`

Question

I'm trying to bind S-mouse-1 which doesn't seem to be as easy as I thought. So far I'm using:

(define-derived-mode foobar-mode nil "foobar")

(define-key foobar-mode-map [S-down-mouse-1]
  (lambda () (interactive)))

(define-key foobar-mode-map [S-mouse-1]
  (lambda () (interactive) (message "S-mouse-1")))

This seems to work but looks really clumsy. Is there a better way to do this? Without this clumsy binding of S-down-mouse-1 I do not get rid of its original binding to 'mouse-appearance-menu.

Note: Eventually I want to put this keymap into a text-property. This is why I want to override this key-binding and not remove it globally.

Answer 1

Yes, I think what you did is what most of us do in such a context. A mouse click involves a down (press) and an up (release) event. If you bind a command to the up event then you typically need to disable any command that might be bound to the down event.

See the Elisp manual, node Click Events.

But you can use this, instead; it's a bit simpler:

(define-key foobar-mode-map [S-down-mouse-1] 'ignore)