How to add a drop down arrow ?

What are the steps to add a drop down arrow to a toolbar button ?

I have been looking at the samples and did'nt see any using this, maybe I missed it. Can someone tell me what sample has it or describe the stpes here. Also how to get notification to react.

thanks,
LOuis.

Ok, now I got the toolbar button menu to be filled up. Oleg, I just need to know if what I did is a good way of doing this ?

//Populate dynamically a toolbar button's drop down menu:

void CMainFrame::OnInitCommandsPopup(CXTPPopupBar* pCommandBar)
{
    CXTPControlPopup *pPopup = pCommandBar->GetControlPopup();

    int nPopupID = pPopup->GetID();

    if( nPopupID == ID_VIEW_GRAPH )
    {
        CXTPControls* pControls = pCommandBar->GetControls();
        pControls->RemoveAll();

        //Fill items
        pControl = pControls->Add(xtpControlButton, ID_GRAPH1, _T(""), i, TRUE);
        pControl->SetCaption(csCaption);

        ...
    }

}

Thanks oleg. I don't need this item to be customized. It is dynamically filled from a list of docking windows (title) that are used to display graphs. When the item is selected the focus is set to the proper commandbar.

One last question on this topic. To avoid creating control IDs and process them with standard message handling mechanism, I used the technique in the sample DynamicPopups for the favorite control. By using the message  map:

i can process the event for the item. To me it all works fine, I just hope it is a good way and no possible conflict. I am working on an existing MFC application that was using the toolbar notification message TBN_DROPDOWN and then using TrackPopupMenu to do this.

This way I don't need to create a control and use OnCalcDynamicSize. I just do it all in the MainFrame.

If using OnCalcDynamicSize is still a better way let me know.

many thanks,
Louis.