Re: `posn-at-point' and `posn-at-x-y' not in manual

[storm@cua.dk (Kim F. Storm)]

David PONCE <david.ponce@wanadoo.fr> writes:

> >>About the `posn-at-point' function, any idea on how to convert the
> >>pixel coordinates it returns, which are relative to a window, into
> >>coordinates relative to the selected frame, to display a tool tip at
> >>point for example?
> > 
> > 
> > window-inside-pixel-edges or window-pixel-edges ?
> 
> Of course!  Thanks!
> As an example, here is an implementation of a `set-mouse-at-point'
> function that seems to work very well :-)
> 
> (defun set-mouse-at-point ()
>   "Move the mouse pointer to pixel position of point."
>   (let* ((pos (posn-at-point))
>          (x-y (posn-x-y pos))
>          (wnd (posn-window pos))
>          (frm (window-frame wnd))
>          (edg (window-pixel-edges wnd)))
>     (set-mouse-pixel-position
>      frm
>      (+ (car x-y) (car  edg) (frame-char-width frm))
>      (+ (cdr x-y) (cadr edg) (/ (frame-char-height frm) 2)))
>     ))


Here are some other nice functions to play with -- maybe something
for line-move to use?

(defun posn-above-point (&optional pos window)
  "Return position above POS in WINDOW."
  (let ((posn (posn-at-point pos window)))
    (if posn
	(let ((x-y (posn-x-y posn)))
	  (posn-at-x-y (car x-y) (1- (cdr x-y)))))))

(defun posn-below-point (&optional pos window)
  "Return position below POS in WINDOW."
  (let ((posn (posn-at-point pos window)))
    (if posn
	(let ((x-y (posn-x-y posn))
	      (w-h (posn-object-width-height posn)))
	  (posn-at-x-y (car x-y) (+ (cdr x-y) (cdr w-h)))))))

Of course, the caller should check whether the returned posn is
in the same window as point, or that it doesn't hit the
modeline ...

-- 
Kim F. Storm <storm@cua.dk> http://www.cua.dk