How to use mobile theme skin as a background for our application.

1. Enable skins support in our application by calling apps AppUi base constructor:

void CMyAppUi::ConstructL()
{
 BaseConstructL(EAknEnableSkin);
 ...
}

2. We will require a specific context to hold the skin bitmap for your control.

CAknsBasicBackgroundControlContext* iBgContext;

3. Initialise context to a reference of the background bitmap:

void CMyAppView::ConstructL()
{
 ...
 iBgContext = CAknsBasicBackgroundControlContext::NewL( KAknsIIDQsnBgAreaMain,aRect,ETrue);
 ...
}

4. Don't forget to call the context destructor:

void CSkinDemoAppView::~CSkinDemoAppView()
{
 ...
 delete iBgContext;
 ...
}

5. As we are ready with a context that has the backgoround that we want to use in all controls. This is done throgh MOP relationship and we need to override the MopSupplyObject():

TTypeUid::Ptr CMyAppView::MopSupplyObject(TTypeUid aId)
{
 if (iBgContext )
 {
   return MAknsControlContext::SupplyMopObject( aId, iBgContext );
 }
 return CCoeControl::MopSupplyObject(aId);
}

6. Each control Draw now be updated to display the skin as background:

void CMyAppView::Draw(const TRect& aRect) const
{
 // Get the standard graphics context
 CWindowGc& gc = SystemGc();
  
 // Redraw the background using the default skin
 MAknsSkinInstance* skin = AknsUtils::SkinInstance();
 MAknsControlContext* cc = AknsDrawUtils::ControlContext( this );
 AknsDrawUtils::Background( skin, cc, this, gc, aRect );

 ...
}

and

void CMyAppView::SizeChanged()
{
 if(iBgContext)
 {
       iBgContext->SetRect(Rect());
    if ( &Window() )
    {
        iBgContext->SetParentPos( PositionRelativeToScreen() );
    }
 }
}

7. Now we are ready so if we have to use it in a list box then we can use as below.
ListBox->ItemDrawer()->ColumnData()->SetSkinEnabledL(ETrue)

Header Files: AknsDrawUtils.h, AknsBasicBackgroundControlContext.h
Lib Files: aknskins.lib aknskinsrv.lib

note:
1. Nokia has introduced skin support only in S60 v2.
2. Unfortunately, the Skin API is not very well documented and may not be compatible in S60 3rd Edition