RWindowGroup mystery

[sadysta]

The question is - why the code below doesn't display window immediately if I change EnableReceiptOfFocus(EFalse) to EnableReceiptOfFocus(ETrue). I get 3-4s of delay when starting or switching to such application. Yes, that's the code from Forum Nokia Wiki!

#include <e32base.h>
#include <w32std.h>     // ws32.lib
#include <coedef.h>
class CCustomGraphics : public CActive
    {
public:
    static CCustomGraphics* NewL();
    void CustomDraw( TRect& aRect );
    virtual ~CCustomGraphics();
protected:
    CCustomGraphics();
    void    ConstructL();
    // from CActive
    void    DoCancel();
    void    RunL();
protected:
    RWsSession       iWsSession;
    CWsScreenDevice* iScreenDevice;
    RWindowGroup     iWindowGroup;
    RWindow*         iWindow;
    CWindowGc*       iWindowGc;
    };
CCustomGraphics::CCustomGraphics()
: CActive( CActive::EPriorityLow )
    {
    CActiveScheduler::Add( this );
    }
CCustomGraphics* CCustomGraphics::NewL()
    {
    CCustomGraphics* self = new (ELeave) CCustomGraphics;
    CleanupStack::PushL( self );
    self->ConstructL();
    CleanupStack::Pop(); // self;
    return self;
    }   
void CCustomGraphics::ConstructL()
    {
    // Connect to window server session
    User::LeaveIfError( iWsSession.Connect() );  
    // Set client priority permanently to current level. See documentation on
    // RWsSession for more information
    iWsSession.ComputeMode( RWsSession::EPriorityControlDisabled );
    iScreenDevice = new (ELeave) CWsScreenDevice( iWsSession );
    User::LeaveIfError( iScreenDevice->Construct() );
    iScreenDevice->SetScreenModeEnforcement( ESizeEnforcementNone );
iWindowGroup = RWindowGroup( iWsSession );
    User::LeaveIfError( iWindowGroup.Construct( (TUint32)this, ETrue ) );
    // This window group cannot receive keyboard focus
    iWindowGroup.EnableReceiptOfFocus( EFalse );
    // Window group will always be on top
    iWindowGroup.SetOrdinalPosition( 0, ECoeWinPriorityAlwaysAtFront+1 );
    // Create graphics context for the screen device
    User::LeaveIfError(iScreenDevice->CreateContext( iWindowGc ) );

    // Finally, create a window, set its properties, and display it
    iWindow = new (ELeave) RWindow( iWsSession );
    User::LeaveIfError(iWindow->Construct( iWindowGroup, (TUint32)iWindow ) );
    iWindow->SetExtent( TPoint( 10, 10 ), TSize( 100, 100 ) );
    iWindow->SetOrdinalPosition(0, ECoeWinPriorityAlwaysAtFront+1 );
    iWindow->SetCornerType( EWindowCorner5 );
    iWindow->SetNonFading( ETrue );
    iWindow->SetVisible( ETrue );
    iWindow->Activate();
    // Start waiting for redraw events
    iWsSession.RedrawReady( &iStatus );
    SetActive();
    }
CCustomGraphics::~CCustomGraphics()
    {
    Cancel();
    iWindow->Close();
    delete iWindow;
    iWindowGroup.Close();
    delete iWindowGc;
    delete iScreenDevice;
    iWsSession.Close();
    }
void CCustomGraphics::RunL()
    {
    if( iStatus == KErrNone )
        {
        TWsRedrawEvent event;
        iWsSession.GetRedraw( event );   
        // Handle of the window which is the target of redraw event
        // Can be used for ID purposes if multiple windows are used
        RWindow* window = ( RWindow* )( event.Handle() );   
        // Rectangle that needs to be redrawn
        TRect eventRect = event.Rect();
        CustomDraw( eventRect );                 
        iWsSession.RedrawReady( &iStatus );
        SetActive();
        }
    }
void CCustomGraphics::DoCancel()
    {
    iWsSession.RedrawReadyCancel();
    }
void CCustomGraphics::CustomDraw( TRect& /*aRect*/ )
    {
    iWindowGc->Activate( *iWindow );
    iWindow->BeginRedraw();
    iWindowGc->SetBrushStyle( CGraphicsContext::ESolidBrush );
    iWindowGc->SetBrushColor( TRgb( 255, 0, 0 ) );
    iWindowGc->Clear();
    iWindow->EndRedraw();
    iWindowGc->Deactivate();
    iWsSession.Flush();
    }

Everything works just the way it should except there is this super strange delay. Any clue?

[sadysta]

*Bump* *bump*

[symbianyucca]

Never had a such problem, so I would think maybe others have not gotten it either, though I usually use non-focusing windows, if I do it that way. Anyway, can you add some time measurements, and see where the time is spend.