Re: CEdit linespacing

From:
"Jonathan Wood" <jwood@softcircuits.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Wed, 30 Aug 2006 18:55:55 -0600
Message-ID:
<e98lniJzGHA.4232@TK2MSFTNGP05.phx.gbl>
Roger,

Okay, getting the TEXTMETRICS works for the vertical size, but now I see
that there is a horizontal offset that does not seem to be constant when
the
font varies and does not seem to correpond to one of the entries in
TEXTMETRIC. Any ideas on how to figure out the horizontal offset?


There is a margin for edit controls. Check out the edit messages--I think
there's one to return the margins. You can see if that helps.

I originally just tried to use an edit control (read only) to display the
text. However, my text may be updated frequently (tens of times/sec-it
comes
from an attached instrument) and I found that every time I called
SetWindowText it would scroll to the beginning. I tried various things
but
found that bitblt'ing the bitmap as I mentioned gave me the "smoothest"
look
when the text changes a lot. It worked fine until now that I am trying to
allow changing the font programmatically. Previously I just set the font
and
hard-coded the offsets I had found experimentally (admittedly not a good
solution). Do you think the owner-draw window would be a better solution?


It's not clear to me if you are concerned about the speed, or the flicker?

An edit control isn't ideal for logging. I've written a few custom logging
controls for this purpose. But I'm not sure they're that much faster. And,
if you're updating the display, then I don't know what your concerns about
be about flickering.

It is common to write to a bitmap first and then bitblt the bitmap to the
screen. Although this is slower than just drawing to the window, there is
less flicker and it appears "smoother". But it's not really clear to me how
much information it is you're showing or how often the display needs to be
updated.

--
Jonathan Wood
SoftCircuits Programming
http://www.softcircuits.com

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