The GtkCellAreaBox renders cell renderers into a row or a column depending on its GtkOrientation. GtkCellAreaBox uses a notion of <emphasis>packing</emphasis>. Packing refers to adding cell renderers with reference to a particular position <emphasis>start</emphasis> and the <emphasis>end</emphasis> of the box. When the GtkCellAreaBox is oriented in the %GTK_ORIENTATION_VERTICAL orientation, the start is defined as the top of the box and the end is defined as the bottom. In the %GTK_ORIENTATION_HORIZONTAL orientation start is defined as the left side and the end is defined as the right side. Alignments of GtkCellRenderers rendered in adjacent rows can be configured by configuring the GtkCellAreaBox:align child cell property with gtk_cell_area_cell_set_property() or by specifying the "align" argument to gtk_cell_area_box_pack_start() and gtk_cell_area_box_pack_end().