Re: edit control from scratch

From:
"Jonathan Wood" <jwood@softcircuits.com>
Newsgroups:
microsoft.public.vc.mfc
Date:
Wed, 22 Apr 2009 08:46:13 -0600
Message-ID:
<#5qqXk1wJHA.6068@TK2MSFTNGP05.phx.gbl>
Well, with that lengthy description, it seems strange you didn't mention WHY
you are avoiding the Windows EDIT control. But, anyway:

This is not that hard of a task. Any plain-old window will work. You'll be
drawing the content yourself.

If you don't need to manage a very large amount of text, you can simply
store the underlying text in a string. When your control needs to repaint,
just print the text in the control.

You'll also need to track the current caret position. When the control gets
focus, create a caret and destroy it when the control loses the focus. You
can use the Windows GDI routines to get the width of characters in order to
determine the exact caret position.

If you want selection and mouse support, you have a bit more work but
nothing particularly difficult to figure out.

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

"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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