The decoration layout for buttons.
If this property is not set, the
GtkSettings:gtk-decoration-layout setting is used.
There can be valid reasons for overriding the setting, such as a header bar design that does not allow for buttons to take room on the right, or only offers room for a single close button. Split header bars are another example for overriding the setting.
The format of the string is button names, separated by commas. A colon separates the buttons that should appear on the start from those on the end. Recognized button names are minimize, maximize, close, icon (the window icon) and menu (a menu button for the fallback app menu).
For example, “menu:minimize,maximize,close” specifies a menu on the left, and minimize, maximize and close buttons on the right.