On Tuesday, August 4, 1998 at 8:00:00 AM UTC+1, Stewart Brodie wrote:
> In message <na.264f8e4870....@argonet.co.uk>
> Everymans Wine <ever...@argonet.co.uk> wrote:
> > In article <486FE03048%sbr...@acorn.com>, Stewart Brodie
> > <sbr...@acorn.com> wrote:
> > :) I am aware of with Wimp_SetExtent is that the extent you set must
> > :) encompass
> > :) the currently visible work area of the window.
> >
> > So hang on a mo... I can't make a window any _bigger_ than it already is,
> > only smaller. In that case I would have to delete the window and recreate
> > it with a larger work area if I wanted a bigger one.
> No, the other way around. If you want to make it smaller so that the
> currently visible work area does not lie within the window extent, then you
> have to re-open the window at an appropriate smallness or close then re-open
> it etc.
> If you are making the window bigger, then there is no problem.
> I forget if you mentioned this before, but if you do have access to the PRMs,
> then you should re-read page 3-164 and 3-165 (and possible pages 3-10 to 3-14
> which describe the layout of windows).
> > To make it clear:
> >
> > -My window has a vertical scroll bar.
> > -When it is first opened the widow is set to a length and the inner part of
> > the vertical scroll bar is at full length (i.e. you can't scroll)
> > -If someone drags an app to the window the _area_ of the window should be
> > increased but the window doesn't get any bigger on screen, the scroll bar
> > is just redrawn to show that you can now scroll to another part of the
> > window. This is utillised to great effect in VTi's Voyager email and
> > newsreader apps but I can't get it to work. Is it possible?
> Yes - it's the simplest form of extent changing there is. If you take the
> top-left hand corner of the document as (0,0) (which is the commonest thing
> to do under RISC OS)with negative Y co-ordinates going down the screen and
> positive X co-ordinates running to the right, then you need to decrease the
> minimum Y.
> BASIC code to increase the vertical size of such a window by 40 units:
> DIM winfo_block% 92
> !winfo_block% = window_handle%
> SYS "Wimp_GetWindowInfo", ,winfo_block% + 1
> winfo_block%!48= (winfo_block%!48) - 40
> SYS "Wimp_SetExtent",window_handle%,winfo_block%+44
> Hmm. maybe I should have used something more readable. Anyway, that's it.
>
Have to say have just found this old discussion thread very interesting an informative.

Just goes to show how useful Google Groups can be when looking for examples!