Ensuring Scroll Bar Background is drawn properly

Comments

(no comments yet)

Log in or Join to leave comments.

Article Metadata

---

Article

Created: bharatuppal (06 Jul 2007)

Last edited: hamishwillee (23 Jul 2012)

Overview:

Platform(s): Symbian 3rd Edition, Symbian 3rd Edition, FP1

When drawing a control (list box, grid, editor, etc.) that uses a scroll bar, the background of the scroll bar may remain white. This happens when a container does not pass the correct object (context-specific skin parameters) to its child controls. Proper skinning for child controls can be can be enabled by implementing the CCoeControl::MopSupplyObject() method for the container class, and making sure that the object provider chain between controls and their parents is set up correctly.

For more information, see SDK documentation on MObjectProvider and CCoeControl::SetMopParent()

Solution:

To correctly draw scroll bar backgrounds:

First, add the following code to the constructor of the view class derived from CCoeControl:

   // make this as member variable
   CAknsBasicBackgroundControlContext*  iSkinContext; 
 
   iSkinContext = CAknsBasicBackgroundControlContext::NewL(
            KAknsIIDQsnBgAreaMainAppsGrid,
            iAvkonAppUi->ApplicationRect(),
            EFalse );

Note: When using the 'KAknsIIDQsnBgAreaMainAppsGrid' skinID, provide the application (full screen) rect as above. Then, implement MopSupplyObject() as follows:

   TTypeUid::Ptr CMyCustomGridAppView::MopSupplyObject( TTypeUid aId )
       {
        if( aId.iUid == MAknsControlContext::ETypeId && iSkinContext != NULL )
           {
           return MAknsControlContext::SupplyMopObject( aId, iSkinContext );
           }     
        return CCoeControl::MopSupplyObject( aId );
       }