Sample wxWidgets app for testing the CodeLineInput widget.

CodeLineInput.cpp

#include "CodeLineInput.h"

const wxRegEx CodeLineInput::HEXCHAR(_T("\\A[0-9A-Fa-f]\\Z"), wxRE_ADVANCED);

CodeLineInput::CodeLineInput(wxWindow *parent, wxWindowID id,
                             const wxString &value, const wxPoint &pos,
                             const wxSize &size, long style,
                             const wxValidator &validator,
                             const wxString &name)
             : wxTextCtrl(parent, id, value, pos, size,
                          style, validator, name)
{
    // Line of code with a space- 17 characters long.
    SetMaxLength(17);

    Connect(wxEVT_KEY_DOWN, wxKeyEventHandler(CodeLineInput::mOnKeyDown));
    Connect(wxEVT_COMMAND_TEXT_UPDATED,
            wxCommandEventHandler(CodeLineInput::mOnTextUpdated));
}

/** Events **/

void CodeLineInput::mOnKeyDown(wxKeyEvent &evt)
{
    // If the user clicks right after the space and tries to delete it, skip
    // the insertion point to the character right before the space, so it
    // deletes that.
    if (GetInsertionPoint() == 9 && evt.GetKeyCode() == WXK_BACK)
        SetInsertionPoint(8);

    evt.Skip();
}

void CodeLineInput::mOnTextUpdated(wxCommandEvent &WXUNUSED(evt))
{
    mFormatText();
}

/** Helpers **/

void CodeLineInput::mFormatText(void)
{
    wxString text = mStripToHex(GetValue());
    wxString final;

    for (size_t i = 0; i < text.Len(); ++i)
    {
        if (i == 8)
            final += _T(' ');
        final += text[i];
    }

    // An attempt at a hack to get it to just work, but no good.
    // For some reason when you enter that 9th character, this method runs
    // again, not going into the conditional the second time. Maybe it's the
    // ChangeValue() that does it for some reason?
    if (final.Len() == 10 && GetValue().Len() == 10)
    {
        SetInsertionPointEnd();
    }

    // Most of the time this won't even change anything, so don't apply the
    // space adjustment unless it needs to be done.
    if (final != GetValue())
    {
        int pos = GetInsertionPoint();
        ChangeValue(final);
        SetInsertionPoint(pos);
    }
}

wxString CodeLineInput::mStripToHex(wxString str)
{
    /**
     * Strip all non-hex characters from str and return the result.
    **/

    wxString output;

    for (size_t i = 0; i < str.Len(); ++i)
        if (HEXCHAR.Matches(str[i]))
            output += str[i];

    return output.Upper().Left(16);
}

CodeLineInput.h

#ifndef CODELINEINPUT_H_INCLUDED
#define CODELINEINPUT_H_INCLUDED

#include <wx/textctrl.h>

#include <wx/regex.h>

class CodeLineInput : public wxTextCtrl
{
public:
    CodeLineInput(wxWindow *parent,
                  wxWindowID id,
                  const wxString &value=_T(""),
                  const wxPoint &pos=wxDefaultPosition,
                  const wxSize &size=wxDefaultSize,
                  long style=0,
                  const wxValidator &validator=wxDefaultValidator,
                  const wxString &name=wxTextCtrlNameStr);

private:
    static const wxRegEx HEXCHAR;

    void mOnKeyDown(wxKeyEvent &evt);
    void mOnTextUpdated(wxCommandEvent &evt);

    void mFormatText(void);
    wxString mStripToHex(wxString str);
};

#endif // CODELINEINPUT_H_INCLUDED

main.cpp

#include <wx/app.h>
#include <wx/frame.h>
#include <wx/panel.h>
#include <wx/sizer.h>
#include "CodeLineInput.h"

class TestApp : public wxApp
{
public:
    virtual bool OnInit(void);
};

class TestFrame : public wxFrame
{
public:
    TestFrame(void);
};

TestFrame::TestFrame(void) : wxFrame(NULL, wxID_ANY, _T("CodeLineInput Test"))
{
    wxPanel *panel = new wxPanel(this, wxID_ANY);
    wxBoxSizer *sizer = new wxBoxSizer(wxHORIZONTAL);

    CodeLineInput *input = new CodeLineInput(panel, wxID_ANY);
    input->SetMinSize(wxSize(250, input->GetSize().GetY()));

    sizer->Add(input, 1, wxEXPAND | wxALL, 5);
    panel->SetSizer(sizer);
    sizer->SetSizeHints(this);

    Center();
}

IMPLEMENT_APP(TestApp)

bool TestApp::OnInit()
{
    TestFrame *frame = new TestFrame();
    frame->Show(true);
    return true;
}

Makefile

all: clean
all: test
all: run

clean:
	@touch test
	@rm test

run:
	@./test

test:
	g++ `wx-config --cxxflags --libs` main.cpp CodeLineInput.cpp -o test