From Forum Nokia Wiki

If we now wanted to create and display a CCoeControl, we'd need to have a CONE environment (CCoeEnv) as a minimum, as this class is used internally by the control. This makes things easier, given that CCoeEnv, as its name implies, creates a whole environment for us, thus limiting our task to the proper control creation:

Library required:

LIBRARY   euser.lib //CTrapCleanup
LIBRARY   ws32.lib //RWsSession,RWindow
LIBRARY   cone.lib //CCoeEnv
LIBRARY   eikcoctl.lib  //CEikTextListBox,CTextListBoxModel

Source:

#include <coedef.h>      // TCoeWinPriority
#include <e32base.h>    // CTrapCleanup
#include <w32std.h>     // RWsSession
#include <coecntrl.h>    // CCoeControl
#include <coemain.h>    // CCoeEnv
 
class CMyControl : public CCoeControl
{
public:
    void ConstructL(const TRect& aRect);
 
private:
    void Draw(const TRect& aRect) const;
};
 
void CMyControl::ConstructL(const TRect& aRect)
{
    CreateWindowL();
 
    SetRect(aRect);
    ActivateL();
}
 
void CMyControl::Draw(const TRect& aRect) const
{
    // Just paint it blue
 
    CWindowGc& gc = SystemGc();
    gc.SetBrushStyle(CGraphicsContext::ESolidBrush);
    gc.SetBrushColor(KRgbBlue);
    gc.SetPenStyle(CGraphicsContext::ENullPen);
 
    gc.Clear(aRect);
}
 
// S60 screen size
const TUint screenWidth  = 176;
const TUint screenHeight = 208;
 
LOCAL_C void ExeMainL()
{
    CCoeEnv::Static()->RootWin().SetOrdinalPosition(0, ECoeWinPriorityAlwaysAtFront);
 
    CMyControl* ctrl = new(ELeave) CMyControl;
    CleanupStack::PushL(ctrl);
 
    ctrl->ConstructL(TRect(0, 0, screenWidth, screenHeight));
    ctrl->DrawNow();
 
    CCoeEnv::Static()->WsSession().Flush();
 
    CleanupStack::PopAndDestroy(ctrl);
}
 
GLDEF_C TInt E32Main()
{
#if defined(__WINS__)
    // WINS already creates environment for us
    CCoeEnv* coe = CCoeEnv::Static();
#else
    CCoeEnv* coe = new CCoeEnv;
    TRAPD(err, coe->ConstructL());
    __ASSERT_ALWAYS(!err, User::Panic(_L("EXECTRL"), err));
#endif
 
    TRAPD(error, ExeMainL());
    __ASSERT_ALWAYS(!error, User::Panic(_L("EXECTRL"), error));
 
    User::After(3*1000*1000);
 
#if !defined(__WINS__)
    coe->DestroyEnvironment();
#endif
 
    return 0;
}
 
#if defined(__WINS__)
EXPORT_C TInt WinsMain()
{
    E32Main();
    User::Exit(0);
    return KErrNone;
}
 
TInt E32Dll(TDllReason)
{
    return KErrNone;
}
#endif

Note that the emulator creates on our behalf an environment when loading an exedll/epocexe as .app, so we have to avoid creating a new environment on emulator builds, otherwise, we'd get a CONE 2 panic (Environment already exists)

Now moving a step further, we'd like to use existing controls, such as listboxes, dialogs, etc. In most cases, a CONE environment won't be enough, so we'll have to resort on the Eikon environment:

#include <coedef.h>      // TCoeWinPriority
#include <e32base.h>    // CTrapCleanup
#include <w32std.h>     // RWsSession
#include <coecntrl.h>    // CCoeControl
#include <eikenv.h>      // CEikonEnv
#include <eiktxlbx.h>     // CEikTextListBox
#include <eiktxlbm.h>    // CTextListBoxModel
 
class CMyControl : public CCoeControl
{
public:
    void ConstructL(const TRect& aRect);
    ~CMyControl();
 
private:
    void SizeChanged();
    TInt CountComponentControls() const;
    CCoeControl* ComponentControl(TInt aIndex) const;
 
    void Draw(const TRect& aRect) const;
 
private:
    CEikTextListBox* iListBox;
};
 
void CMyControl::ConstructL(const TRect& aRect)
{
    CreateWindowL();
 
    // You may use CAknSingleStyleListBox, etc for Series 60..
    iListBox = new(ELeave) CEikTextListBox;
    iListBox->SetContainerWindowL(*this);
//    iListBox->SetMopParent(this);
    iListBox->ConstructL(this);
 
    CDesCArray* items = static_cast<CDesCArray*> (iListBox->Model()->ItemTextArray());
    _LIT(KItem1, "First");
    items->AppendL(KItem1);
    _LIT(KItem2, "Second");
    items->AppendL(KItem2);
 
    iListBox->HandleItemAdditionL();
    iListBox->SetFocus(ETrue);
 
//    iListBox->CreateScrollBarFrameL();
//    iListBox->ScrollBarFrame()->SetScrollBarVisibilityL(CEikScrollBarFrame::EOff, CEikScrollBarFrame::EAuto);
 
    SetRect(aRect);
    ActivateL();
}
 
CMyControl::~CMyControl()
{
    delete iListBox;
}
 
void CMyControl::SizeChanged()
{
    iListBox->SetRect(Rect());
}
 
TInt CMyControl::CountComponentControls() const
{
    return 1;
}
 
CCoeControl* CMyControl::ComponentControl(TInt aIndex) const
{
    switch (aIndex)
    {
        case 0:
            return iListBox;
 
        default:
            return 0;
    }
}
 
void CMyControl::Draw(const TRect& aRect) const
{
    CWindowGc& gc = SystemGc();
    gc.Clear(aRect);
}
 
// S60 screen size
const TUint screenWidth  = 176;
const TUint screenHeight = 208;
 
LOCAL_C void ExeMainL()
{
    CCoeEnv::Static()->RootWin().SetOrdinalPosition(0, ECoeWinPriorityAlwaysAtFront);
 
    CMyControl* ctrl = new(ELeave) CMyControl;
    CleanupStack::PushL(ctrl);
 
    ctrl->ConstructL(TRect(0, 0, screenWidth, screenHeight));
    ctrl->DrawNow();
 
    CCoeEnv::Static()->WsSession().Flush();
 
    CleanupStack::PopAndDestroy(ctrl);
}
 
GLDEF_C TInt E32Main()
{
#if defined(__WINS__)
    // WINS already creates environment for us
    CEikonEnv* coe = CEikonEnv::Static();
#else
    CEikonEnv* coe = new CEikonEnv;
    TRAPD(err, coe->ConstructL());
    __ASSERT_ALWAYS(!err, User::Panic(_L("EXECTRL"), err));
#endif
 
    TRAPD(error, ExeMainL());
    __ASSERT_ALWAYS(!error, User::Panic(_L("EXECTRL"), error));
 
    User::After(3*1000*1000);
 
#if !defined(__WINS__)
    delete coe;
#endif
 
    return 0;
}
 
#if defined(__WINS__)
EXPORT_C TInt WinsMain()
{
    E32Main();
    User::Exit(0);
    return KErrNone;
}
 
TInt E32Dll(TDllReason)
{
    return KErrNone;
}
#endif

The example above shows a pretty simple compound control, consisting of just one lodger control, a text listbox. But to make this a bit more useful, we'd need to receive events (such as key presses) and pass them to the control. The example bellow shows a simple implementation. Actually, it mimics somehow CCoeEnv::ExecuteD() functionality, which basically starts the active scheduler and waits for events from the window server (note that CCoeEnv is a CActive)

LOCAL_C void ExeMainL()
{
    CCoeEnv* coeEnv = CCoeEnv::Static();
    coeEnv->RootWin().SetOrdinalPosition(0, ECoeWinPriorityAlwaysAtFront);
 
    CMyControl* ctrl = new(ELeave) CMyControl;
    CleanupStack::PushL(ctrl);
 
    ctrl->ConstructL(TRect(0, 0, screenWidth, screenHeight));
    ctrl->DrawNow();
 
    coeEnv->WsSession().Flush();
 
    // Create a basic UI and set control to receive events
    CMyAppUi* appUi = new(ELeave) CMyAppUi;
    appUi->SetRootControl(ctrl);
    coeEnv->SetAppUi(appUi);    // takes ownership
 
    for (;;)
    {
        // Wait synchronously for event
        TRequestStatus status;
        coeEnv->WsSession().EventReady(&status);
        User::WaitForRequest(status);
 
        if (status.Int() == KErrNone)
        {
            TWsEvent event;
            coeEnv->WsSession().GetEvent(event);
 
            // Check exit key
            if (event.Key()->iCode == EKeyDevice3)
                break;
 
            // Pass event to control
            appUi->HandleWsEventL(event, ctrl);
        }
    }
 
    CleanupStack::PopAndDestroy(ctrl);
}

You May Download the examples here:

ExeCtrl.zip (CONE environment)

ExeCtrl.zip (Eikon environment)

Related Links:

• How to capture Keyevents in thread or exe
• Graphics in EXE
• How to Launch an EXE and Pass Command Line Arguments
• How to start EXE from an EXE in 3rd Edition
• How to get ReDraw event in exe from window server?