[Q] formatting chapter title to one line

[Han The Thanh <thanh@informatics.muni.cz>]

Hi all,

I wish to format a chapter title (in appendix part) like:

                  A. <my chapter title>

I did try the following:

\setuphead[chapter][
    appendixlabel=,
    stype=\tfc,
    textstyle=bf,
    alternative=middle]

but the title is broken into two lines like:

                         A
                  <my chapter title>

So I tried next:

\setuphead[chapter][
    appendixlabel=,
    stype=\tfc,
    textstyle=bf,
    alternative=middle,
    command=\catalogchapter,
    alternative=middle]

\def\catalogchapter#1#2{%
    \hbox to \hsize{\hss#1.~#2\hss}
}

Now I get the title formatted into one line, but there are still two
problems:

1) the dot character doesn't get the correct size (it's smaller than the
   title text)

2) textstyle seems to be applied to the title text only, however the title
   number (which is A) remains the default (\rm).

Can someone please tell me what I am missing? 

Thanks,
Thanh