OnPaint on wxWidgets/wxPython その4

from gtk src/gtk/window.cpp
こっちはGTKのRefreshとUpdate。あまりひねりはなさそう。

void wxWindowGTK::Refresh(bool WXUNUSED(eraseBackground),
                          const wxRect *rect)
{
    if (!m_widget)
        return;
    if (!m_widget->window)
        return;

    if (m_wxwindow)
    {
        if (m_wxwindow->window == NULL) return;

        GdkRectangle gdk_rect,
                    *p;
        if (rect)
        {
            gdk_rect.x = rect->x;
            gdk_rect.y = rect->y;
            gdk_rect.width = rect->width;
            gdk_rect.height = rect->height;
            if (GetLayoutDirection() == wxLayout_RightToLeft)
                gdk_rect.x = GetClientSize().x - gdk_rect.x - gdk_rect.width;

            p = &gdk_rect;
        }
        else // invalidate everything
        {
            p = NULL;
        }

        gdk_window_invalidate_rect(m_wxwindow->window, p, true);
    }
}

void wxWindowGTK::Update()
{
    GtkUpdate();

    // when we call Update() we really want to update the window immediately on
    // screen, even if it means flushing the entire queue and hence slowing down
    // everything -- but it should still be done, it's just that Update() should
    // be called very rarely
    gdk_flush();
}

void wxWindowGTK::GtkUpdate()
{
    if (m_wxwindow && m_wxwindow->window)
        gdk_window_process_updates(m_wxwindow->window, false);
    if (m_widget && m_widget->window && (m_wxwindow != m_widget))
        gdk_window_process_updates( m_widget->window, FALSE );

    // for consistency with other platforms (and also because it's convenient
    // to be able to update an entire TLW by calling Update() only once), we
    // should also update all our children here
    for ( wxWindowList::compatibility_iterator node = GetChildren().GetFirst();
          node;
          node = node->GetNext() )
    {
        node->GetData()->GtkUpdate();
    }
}

んで、macはどうかというと、ちょっと？なかんじ。HIXXってなんぞや？
src/mac/window.cpp

/*
 * Rect is given in client coordinates, for further reading, read wxTopLevelWindowMac::InvalidateRect
 * we always intersect with the entire window, not only with the client area
 */

void wxWindowMac::Refresh(bool WXUNUSED(eraseBack), const wxRect *rect)
{
    if ( m_peer == NULL )
        return ;

    if ( !IsShownOnScreen() )
        return ;

    if ( rect )
    {
        Rect r ;

        wxMacRectToNative( rect , &r ) ;
        m_peer->SetNeedsDisplay( &r ) ;
    }
    else
    {
        m_peer->SetNeedsDisplay() ;
    }
}

SetNeedsDisplayはなにものかというと、src/mac/carbon/utils.cppのなかにいらっしゃって、

void wxMacControl::SetNeedsDisplay( RgnHandle where )
{
    if ( !IsVisible() )
        return;

    HIViewSetNeedsDisplayInRegion( m_controlRef , where , true );
}

ふたたびsrc/mac/window.cppのなかにもどってUpdateがどうなっているかというと、

void wxWindowMac::Update()
{
    wxNonOwnedWindow* top = MacGetTopLevelWindow();
    if (top)
        top->MacPerformUpdates() ;
}

src/mac/carbon/nonownedwnd.cpp

void wxNonOwnedWindow::MacPerformUpdates()
{
    // for composited windows this also triggers a redraw of all
    // invalid views in the window
    HIWindowFlush((WindowRef) m_macWindow) ;
}