set-temporary-overlay-map doesn't work for me

set-temporary-overlay-map doesn't work for me

[Andrey Tykhonov]

Hi all,

I have two quite simple functions:

(defun my-temp ()
  (interactive)
  (set-temporary-overlay-map
   (let ((map (make-sparse-keymap)))
     (define-key map [mouse-1] 'my-mouse-down)
     map)))

(defun my-mouse-down ()
  (interactive)
  (message "Word is: %s " (thing-at-point 'word)))


I evaluate them, then M-x my-temp RET, then mouse click (left button) on
"interactive" world and I'm expecting to see "Word is "interactive""
message in the minibuffer. But no messages appear! I cannot figure out
why this code behaves in such way...

By the way I have tried (global-set-key [mouse-1] 'my-mouse-down) and
this works and I see the message. Also I've tried:

(define-key map (kbd "C-c C-c") 'my-mouse-down) and this code also works well.

But I need mouse click to be processed and to be processed only once!

What trouble with these two functions?

P.S.: Values of `overriding-terminal-local-map` and `overriding-local-map`
variables are nil.


Best regards,
Andrey

RE: set-temporary-overlay-map doesn't work for me

[Drew Adams]

> (defun my-temp ()
>   (interactive)
>   (set-temporary-overlay-map
>    (let ((map (make-sparse-keymap)))
>      (define-key map [mouse-1] 'my-mouse-down)
>      map)))
> 
> (defun my-mouse-down ()
>   (interactive)
>   (message "Word is: %s " (thing-at-point 'word)))
> 
> I evaluate them, then M-x my-temp RET, then mouse click (left button) on
> "interactive" world and I'm expecting to see "Word is "interactive""
> message in the minibuffer. But no messages appear!

`my-temp' does not read your mouse click.  It binds the keymap, and
then it exits.  And then you click your mouse, with the binding no
longer in effect.

One approach would be to read an event inside your `my-temp', and
ignore it if not a mouse click.  To do something cleaner than that
we would need to see the overall context - what you really want to do.

But if this is all there is, then it seems you want to invoke a
command (why a command?) that reads an event, and if that event is a
mouse click then invoke `my-mouse-down'.  Or perhaps you want to
read events until you get a mouse click event...

Anyway, that's the problem.  Either describe what you really need
or work it out knowing what this problem is.

Re: set-temporary-overlay-map doesn't work for me

[Stefan Monnier]

> I have two quite simple functions:

> (defun my-temp ()
>   (interactive)
>   (set-temporary-overlay-map
>    (let ((map (make-sparse-keymap)))
>      (define-key map [mouse-1] 'my-mouse-down)
>      map)))

> (defun my-mouse-down ()
>   (interactive)
>   (message "Word is: %s " (thing-at-point 'word)))


> I evaluate them, then M-x my-temp RET, then mouse click (left button) on
> "interactive" world and I'm expecting to see "Word is "interactive""
> message in the minibuffer. But no messages appear! I cannot figure out
> why this code behaves in such way...

I think the problem is that clicking with your mouse will do two things:
`down-mouse-1' then `mouse-1' and the first will exit the temporary
overlay map.


        Stefan

Re: set-temporary-overlay-map doesn't work for me

[Andrey Tykhonov]

Drew Adams writes:

>> (defun my-temp ()
>>   (interactive)
>>   (set-temporary-overlay-map
>>    (let ((map (make-sparse-keymap)))
>>      (define-key map [mouse-1] 'my-mouse-down)
>>      map)))
>>
>> (defun my-mouse-down ()
>>   (interactive)
>>   (message "Word is: %s " (thing-at-point 'word)))
>>
>> I evaluate them, then M-x my-temp RET, then mouse click (left button) on
>> "interactive" world and I'm expecting to see "Word is "interactive""
>> message in the minibuffer. But no messages appear!
>
> `my-temp' does not read your mouse click.  It binds the keymap, and
> then it exits.  And then you click your mouse, with the binding no
> longer in effect.

I wonder: why (kbd "C-c C-c") binding (in case if place it instead of
[mouse-1]) still in effect even after `my-temp` exits?

I was expecting that [mouse-1] will be behaved in the same way.

> One approach would be to read an event inside your `my-temp', and
> ignore it if not a mouse click.  To do something cleaner than that
> we would need to see the overall context - what you really want to do.

Well, I'll try read an event!

Thank you a lot!


Best regards,
Andrey

>
> But if this is all there is, then it seems you want to invoke a
> command (why a command?) that reads an event, and if that event is a
> mouse click then invoke `my-mouse-down'.  Or perhaps you want to
> read events until you get a mouse click event...
>
> Anyway, that's the problem.  Either describe what you really need
> or work it out knowing what this problem is.

RE: set-temporary-overlay-map doesn't work for me

[Drew Adams]

> I wonder: why (kbd "C-c C-c") binding (in case if place it instead of
> [mouse-1]) still in effect even after `my-temp` exits?
> I was expecting that [mouse-1] will be behaved in the same way.

No, please ignore my answer to the question - wrong.  I didn't even
notice the call to `set-temporary-overlay-map'.  Sounds like Stefan
is on the right track.