Re: What is normal these days (display.texi)?

[David Kastrup]

address@hidden (Kim F. Storm) writes:

> David Kastrup <address@hidden> writes:
>
>>     @defun redraw-frame frame
>>     @deffn Command redraw-display
>>
>> All of those functions work by _immediately_ clearing the respective
>> frame or display, and then marking it for redisplay.
>>
> If that is not stated already in the docs, we should fix it.
>
>
>> So why change the language in the case that is much less conspicuous
>> (by not clearing the frame) as it does not cause a large blank window
>> to show while Emacs is busy?
>
> The name "force-window-update" (and the original text) 
> indicate an immediate action.

Uh, do you mean "the original text" proposed by me?  I fail to guess
what version you are referring to now.

> But there is no immediate action.
>
> So if a program wants to use, e.g posn-at-x-y, after making changes,
> force-window-update is not the right thing to use to make sure the
> display matrix is up-to-date.

Well, what would be?  Is there any purpose, anyway, to have
posn-at-x-y work with an updated display matrix that has not even been
displayed?

I think we have to come to grips about what posn-at-x-y is intended
for: for associating events with simulated (or real) clicks, or for
some sort of absolute positioning.  For the first, you probably want
the display matrix corresponding to the current display, for the
second, for the updated display.

Whatever.  I have no idea by now what semantics would be desired, and
how the given functions correspond to that.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum