Re: Changes in frame/window code

[martin rudalics]

>> But if that R2L line starts on the right of the right window edge it's
>> larger, I presume.
>
> You mean, if it's hscrolled?  Yes, of course -- exactly like an L2R
> line.

I still have no feeling for how hscrolling works with bidi text.  IIUC
with L2R and R2L paragraphs in the same window, like

LLLLLLLLLLLLLLLLLLLLLL2RRRRRRRRRRRRRRRRRRR

               RRRRRRR2LLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLLL

hscrolling will NOT preserve the aspect that the two "2" visually appear
above each other.  Correct?

> I feel there's some misunderstanding here, because I don't believe
> you'd ask about such trivia.  What am I missing?  What's bothering
> you?

What you said earlier, that "Horizontal scrolling of mixed-direction
paragraphs is a hard problem".

>> Is the size of the slider correct in the sense described above?
>
> Yes.

Did you check with a window containg say one huge L2R line and all
other lines short and one huge R2L line and all other lines short?

>> Then fixing the position should not be that difficult.
>
> I never said it was difficult, just that it has to be on the C level,
> not on the Lisp level, where I fixed the clicks on the scroll bar.

Sure.

>> In any case I would have to tell GTK whether the "current text"
>> (whatever that is) is L2R or R2L I suppose.
>
> Yes, but we have current-bidi-paragraph-direction for that.

The whole idea would be then to change the positions of

      start = w->hscroll * FRAME_COLUMN_WIDTH (WINDOW_XFRAME (w));

and

      end = start + box_width;

on lines 15808 and 15810 of xdisp.c according to the value of
`current-bidi-paragraph-direction'.  But how?

martin