Container.propagateDraw
void propagateDraw(gtk.widget.Widget child, cairo.context.Context cr)When a container receives a call to the draw function, it must send synthetic #GtkWidget::draw calls to all children that don’t have their own #GdkWindows. This function provides a convenient way of doing this. A container, when it receives a call to its #GtkWidget::draw function, calls [gtk.container.Container.propagateDraw] once for each child, passing in the cr the container received.
[gtk.container.Container.propagateDraw] takes care of translating the origin of cr, and deciding whether the draw needs to be sent to the child. It is a convenient and optimized way of getting the same effect as calling [gtk.widget.Widget.draw] on the child directly.
In most cases, a container can simply either inherit the #GtkWidget::draw implementation from #GtkContainer, or do some drawing and then chain to the ::draw implementation from #GtkContainer.
Parameters
child | a child of container |
cr | Cairo context as passed to the container. If you want to use cr in container’s draw function, consider using [cairo.context.Context.save] and [cairo.context.Context.restore] before calling this function. |