Re: edit control from scratch

"AliR \(VC++ MVP\)" <AliR@online.nospam>
Wed, 22 Apr 2009 16:20:18 -0500
Joe we have gone through this many many time. It doesn't like it but it can
be done.

Here is a transparent edit control:


"Joseph M. Newcomer" <> wrote in message

Unfortunately, one of the things that edit controls do *not* support well
is being
transparent. To make this work, in addition to making the control
transparent, you have
to do the background of the text as SetBkMode(TRANSPARENT), and at that
point the edit
control fails completely, because it assumes that it is drawing OPAQUE,
and if you type
a<b<F<# where < represents backspace, you get a "splodge" on the screen
which is the
overwrite of a with b with F with #. This is a real pain to deal with.
So if things are
supposed to show up "under" the edit control, you can't use it.
On Wed, 22 Apr 2009 11:28:28 -0500, "AliR \(VC++ MVP\)"
<AliR@online.nospam> wrote:

You know that you can change the edit control style to display itself in
and you change the font, and the text color and the background color of
edit control.

Here is how to change the background color:

You can figure out the text color from there.


"asellon" <> wrote in message

thanks for replying. I am making the control from scratch because the
entire view of the application is a radar screen. Hence everything is
Graphics.. including all controls. And all controls are created and
by my code.

funny thing is, if I could just see how someone implemented the CEditBox
all the way down to the nuts and bolts, that would totally show me what

but of course that won't happen.

thanks for the hex editor example.

"AliR (VC++ MVP)" <AliR@online.nospam> wrote in message

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,
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
and keeping track of the current index as the user goes from one line

Here is a HexEditor that I wrote a while back, maybe it will help out a


"asellon" <> wrote in message

 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
derive from any common controls.

Something I need, however, is a control that works like an edit box.
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
the font I am using(Hershey fonts are being used... so vector fonts,
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
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
store the characters in. Why?

Because the edit control I am making allows movement throughout by
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.


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
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.

Joseph M. Newcomer [MVP]
MVP Tips:

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