- ((wxScrolledWindow*)(m_Wnd->GetParent()))->GetViewStart(&stx, &sty);
- m_Wnd->SetSize(absx - wxHTML_SCROLL_STEP * stx, absy - wxHTML_SCROLL_STEP * sty, m_Width, m_Height);
+ wxScrolledWindow *scrolwin =
+ wxDynamicCast(m_Wnd->GetParent(), wxScrolledWindow);
+ wxCHECK_RET( scrolwin,
+ _T("widget cells can only be placed in wxHtmlWindow") );
+
+ scrolwin->GetViewStart(&stx, &sty);
+ m_Wnd->SetSize(absx - wxHTML_SCROLL_STEP * stx,
+ absy - wxHTML_SCROLL_STEP * sty,
+ m_Width, m_Height);