parent = priv->parent;
- norender =
- /* If this widget has an opacity group and no window don't render it */
- (priv->opacity_group && !gtk_widget_get_has_window (widget)) ||
- /* If the parent has norender_children, propagate that here */
- (parent != NULL && parent->priv->norender_children);
-
- /* Windowed widget children should norender if: */
+ /* Norender affects only windowed widget and means don't render widget->window in the
+ normal fashion.
+ We only set this if the parent has norender_children, because:
+ a) For an opacity group (that does not have a norender_children parent) we still
+ need to render the window or we will never get an expose event.
+ b) For alpha we set the opacity of window->widget directly, so no other
+ work is needed.
+ */
+ norender = (parent != NULL && parent->priv->norender_children);
+
+ /* windows under this widget should not render if:
+ a) This widget has an opacity group
+ b) This widget has alpha and is no-windowed (otherwise we'd set alpha on widget->window)
+ c) This widget has norender but is no-windowed (a windowed widget would "swallow" the norender)
+ */
norender_children =
- /* The widget is no_window (otherwise its enought to mark it norender/alpha), and */
- !gtk_widget_get_has_window (widget) &&
- ( /* norender is set, or */
- norender ||
- /* widget has an alpha */
- priv->alpha != 255
- );
+ priv->opacity_group ||
+ (!gtk_widget_get_has_window (widget) &&
+ ( norender || priv->alpha != 255));
if (gtk_widget_get_has_window (widget))
{