Re: feature/icomplete-vertical

[Gregory Heytings via "Emacs development discussions." <emacs-devel@gnu.org>]

>> trying to calculate the height of the completion candidate list, which 
>> amount (as Stefan wrote) to redoing what redisplay does.
>
> I don't agree with Stefan, if this interpretation of what he said is 
> correct.  We have window-text-pixel-size to measure the size of text on 
> display without redoing what redisplay does.
>

Do you mean that every function which wants to display something in the 
minibuffer should use window-text-pixel-size to create a text that fits in 
the minibuffer without hiding the prompt?

And that this is better than only expecting such functions to approximate 
the available space, and to rely on the fact that if the text is too large 
the display engine will hide the end of the text instead of the prompt?