gtkLabel setting the label cannot trigger the snapshot callback of the parent control

[q962 (提及)]

I wrote a control: timed scrolling snapshot.

Right now it just contains a GtkLabel. When I set the label, it can receive the size_allocate event, not the snapshot event.
Although gtkLabel will call the gtk_widget_queue_draw function.

[q962 (提及)]

Is it something to do with my snapshot function?

static void lx_scroll_snapshot_snapshot( GtkWidget* widget, GtkSnapshot* snapshot )
{
	_SELF( widget );

	GtkSnapshot* text_snapshot = gtk_snapshot_new();

	GTK_WIDGET_GET_CLASS( self->widget )->snapshot( self->widget, text_snapshot );

	int w = gtk_widget_get_width( widget );
	int h = gtk_widget_get_height( widget );

	cairo_t* cr = gtk_snapshot_append_cairo( snapshot, &GRAPHENE_RECT_INIT( 0, 0, w, h ) );

	GskRenderNode* node = gtk_snapshot_free_to_node( text_snapshot );
	cairo_save( cr );
	cairo_translate( cr, 0.0 - self->offset, 0 );
	gsk_render_node_draw( node, cr );
	cairo_restore( cr );

	int target_width = gtk_widget_get_width( self->widget );
	if ( target_width > w ) {
		int overflow_width = w - target_width;
		int tail_position  = target_width - self->offset;
		if ( w - tail_position > self->trailing_blank_size ) {
			cairo_translate( cr, 0.0 + tail_position + self->trailing_blank_size, 0 );
			gsk_render_node_draw( node, cr );
		}
	}

	cairo_destroy( cr );
	gsk_render_node_unref( node );
}

[q962 (提及)]

The important step I missed: Should call the method of the parent class

GTK_ WIDGET_ CLASS( lx_scroll_snapshot_parent_class )->snapshot( widget, snapshot );