Value | Symbolic name | Description | 
|   0 | GTK_SHADOW_NONE | 
   No shadow is displayed, resulting in a two-dimensional appearance.
   | 
|   1 | GTK_SHADOW_IN | 
   Displays dark shadow on left and upper sides of the widget, resulting
   in the appearance of the widget being lower than its surrounding area.
   | 
|   2 | GTK_SHADOW_OUT | 
   Displays dark shadow on right and lower sides of the widget, resulting
   in the illusion that the widget is raised above its surrounding area.
   | 
|   3 | GTK_SHADOW_ETCHED_IN | 
   Displays the appearance of sunken detail.
   | 
|   4 | GTK_SHADOW_ETCHED_OUT | 
   Displays the appearance of raised detail.
   |