Merging Two Menus

void MergeMenu( CMenu* pMenuDestination, CMenu* pMenuAdd, bool bTopLevel /*=false*/ )
{
    // Abstract:
    //      Merges two menus.
    //
    // Parameters:
    //      pMenuDestination    - [in, retval] destination menu handle

    //      pMenuAdd            - [in] menu to merge
    //      bTopLevel           - [in] indicator for special top level behavior
    //
    // Comments:
    //      This function calles itself recursivley. If bTopLevel is set to true,
    //      we append popups at top level or we insert before <Window> or <Help>.

    // get the number menu items in the menus
    int iMenuAddItemCount = pMenuAdd->GetMenuItemCount();
    int iMenuDestItemCount = pMenuDestination->GetMenuItemCount();

    // if there are no items return
    if( iMenuAddItemCount == 0 )
        return;

    // if we are not at top level and the destination menu is not empty
    // -> we append a seperator
    if( !bTopLevel && iMenuDestItemCount > 0 )
        pMenuDestination->AppendMenu( MF_SEPARATOR );

    // iterate through the top level of <pMenuAdd>
    for( int iLoop = 0; iLoop < iMenuAddItemCount; iLoop++ )
    {
        // get the menu string from the add menu
        CString sMenuAddString;
        pMenuAdd->GetMenuString( iLoop, sMenuAddString, MF_BYPOSITION );

        // try to get the submenu of the current menu item
        CMenu* pSubMenu = pMenuAdd->GetSubMenu( iLoop );

        // check if we have a sub menu
        if( !pSubMenu )
        {
            // read the source and append at the destionation

            VERIFY( pMenuDestination->AppendMenu( 
                            pMenuAdd->GetMenuState( iLoop, MF_BYPOSITION ), 
                            pMenuAdd->GetMenuItemID( iLoop ),
                            sMenuAddString ));
        }
        else
        {
            // create or insert a new popup menu item

            // default insert pos is like ap
            int iInsertPosDefault = -1;

            // if we are at top level merge into existing popups rather than
            // creating new ones
            if( bTopLevel )

                // try to find existing popup
                for( int iLoop = 0; iLoop < iMenuDestItemCount; iLoop++ )
                {
                    // get the menu string from the destination menu
                    CString sDest;
                    pMenuDestination->GetMenuString( iLoop, sDest, MF_BYPOSITION );

                    // we got a hit -> merge the two popups
                    if( sMenuAddString == sDest )
                    {
                        // try to get the submenu of the desired destionation menu item
                        CMenu* pSubMenuDest = MenuDestination->GetSubMenu( iLoop );

                        if( pSubMenuDest )
                        {
                            // merge the popup recursivly and continue with for loop
                            MergeMenu( pSubMenuDest, pSubMenu );
                            continue;
                        }
                    }

                    // alternativ insert before <Window> or <Help>
                    if( iInsertPosDefault == -1 && (sDest == "&Window" || sDest == "&Help" ))
                        iInsertPosDefault = iLoop;
                }
            }

            // if the top level search did not find a position append the menu
            if( iInsertPosDefault == -1 )
                iInsertPosDefault = pMenuDestination->GetMenuItemCount();

            // create a new popup and insert before <Window> or <Help>
            CMenu NewPopupMenu;
            VERIFY( NewPopupMenu.CreatePopupMenu() );

            // merge the new popup recursivly
            MergeMenu( &NewPopupMenu, pSubMenu );

            // insert the new popup menu into the destination menu

            VERIFY( pMenuDestination->InsertMenu( 
                            iInsertPosDefault,
                            MF_BYPOSITION | MF_POPUP | MF_ENABLED, 
                            (UINT)NewPopupMenu.GetSafeHmenu(),
                            sMenuAddString ));

            // don't destroy the new menu           
            NewPopupMenu.Detach();
        }
    }
}