Re: edit control from scratch

From:
"AliR \(VC++ MVP\)" <AliR@online.nospam>
Newsgroups:
microsoft.public.vc.mfc
Date:
Wed, 22 Apr 2009 10:14:32 -0500
Message-ID:
<pwGHl.25189$Ws1.23645@nlpi064.nbdc.sbc.com>
I like to ask why you are doing all your controls from scratch, most windows
controls are highly configurable!?
Let me also point out that there is no such thing as an MFC control, all the
controls that you have access to are windows controls that are available
whether you are using MFC or SDK or ATL...

Anyway, writing an edit control from scratch, although an arduous task, is
not all that difficult. If not done correctly you will endup with alot of
flicker (things like when new chars are typed in not refreshing the entire
control). The hardest part of the whole thing would be the line wrapping
part (keeping track of where the line breaks should happen, and keeping
track of the current index as the user goes from one line to another.)

Here is a HexEditor that I wrote a while back, maybe it will help out a
little.
http://www.learnstar.com/AliR/HexView.zip

AliR.

"asellon" <asellon@cox.net> wrote in message
news:OTFHl.37633$FR3.31067@newsfe04.iad...

Folks,
 I am using MFC as the basis of my application, but all visual components
are drawn using GDI. I don't use any common controls nor do I derive from
any common controls.

Something I need, however, is a control that works like an edit box. I
currently have a control manager object that manages drawing the controls,
checking them for hover and click, and so on.

Each control is simply a rectangle of some arbitrary size with the ability
to have children controls inside, much like panels have edit boxes and so
on in .NET development.

So for an edit control in my world, I have a rectangle that is sized of
the font I am using(Hershey fonts are being used... so vector fonts, not
windows fonts). It has a border(a simple line outlining it). It does not
have to respond to highlighting or drag and drop.

So, the questions.

I can't see MS source code for their edit control to get ideas, so I
thought Java Swing... but I don't know much about the open source-ness of
that stuff. Does some one know of source code somewhere that creates an
edit box and does not use an MFC control derivation to do it?

What would be the best container to back the edit control up with? It
needs to accept characters and strings, which is no problem. But
currently, the idea I have is to use a vector or string from the STL to
store the characters in. Why?

Because the edit control I am making allows movement throughout by arrow
keys and if I have the cursor at a position other than the end and I start
typing, I need to insert the characters at that position in the character
array.

That said, on each redraw, the control needs a CString sent to my hershey
font class in order to draw the string. That part I have handled as well,
in theory.

So... there are tons of resources for making an edit control out of an
already edittable type of control such as an MFC control. What about
starting from complete scratch?

Of course, any ideas about any of this are appreciated. Insults and
ridicule as well. I would just like to get moving forward in a good
fashion towards a solid design for this control.

Thanks for the help, and if this is the wrong place for this, just let me
know.

Andy

Oh, and Dr Newcomer. If you read this, I need to send you an email about
your async socket classes. I would like your advice and keen eye on
something in reference to that if you could spare some time for me. If
not, that will have to be fine as well.

Thank you.

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