| Value | Meaning |
|---|---|
| SPREAD1 | Buttons are evenly spread across the box. |
| EDGE2 | Buttons are placed at the edges of the box. |
| START3 | Buttons are grouped towards the start of the box, (on the left for a HBox, or the top for a VBox). |
| END4 | Buttons are grouped towards the end of the box, (on the right for a HBox, or the bottom for a VBox). |
| CENTER5 | Buttons are centered in the box. Since 2.12. |
| EXPAND6 | Buttons expand to fill the box. This entails giving buttons a "linked" appearance, making button sizes homogeneous, and setting spacing to 0 (same as calling gtk_box_set_homogeneous() and gtk_box_set_spacing() manually). Since 3.12. |
Used to dictate the style that a #GtkButtonBox uses to layout the buttons it contains.