This article shows how to change view mode programmatically:

In RDPDFViewController class you can add this method:

- (void)setReaderViewMode:(int)mode

{

    int currentPage = [m_view vGetCurrentPage];

    if( m_view != nil )

    {

        [m_view vClose];

        [m_view removeFromSuperview];

        m_view = NULL;

    }

    g_def_view = mode;

    [[NSUserDefaults standardUserDefaults] setInteger:mode forKey:@"ViewMode"];

    [[NSUserDefaults standardUserDefaults] synchronize];

    CGRect rect = [[UIScreen mainScreen] bounds];

    if (![self isPortrait] && rect.size.width < rect.size.height) {

        float height = rect.size.height;

        rect.size.height = rect.size.width;

        rect.size.width = height;

    }

    if(SYS_VERSION>=7.0)

    {

        m_view = [[PDFView alloc] initWithFrame:CGRectMake(0, 0, rect.size.width, rect.size.height)];

    }

    else

    {

        m_view = [[PDFView alloc] initWithFrame:CGRectMake(0, 0, rect.size.width, rect.size.height-20-44)];

    }

    [m_view vOpen :m_doc :(id<PDFViewDelegate>)self];

    pagecount =[m_doc pageCount];

    if (m_Thumbview) {

        [self.view insertSubview:m_view belowSubview:m_Thumbview];

    }

    m_bSel = false;

    [self PDFGoto:currentPage];

}