The #GtkMenuButton widget is used to display a popup when clicked on. This popup can be provided either as a #GtkMenu, a #GtkPopover or an abstract #GMenuModel.

The #GtkMenuButton widget can hold any valid child widget. That is, it can hold almost any other standard #GtkWidget. The most commonly used child is #GtkImage. If no widget is explicitely added to the #GtkMenuButton, a #GtkImage is automatically created, using an arrow image oriented according to #GtkMenuButton:direction or the generic “open-menu-symbolic” icon if the direction is not set.

The positioning of the popup is determined by the #GtkMenuButton:direction property of the menu button.

For menus, the #GtkWidget:halign and #GtkWidget:valign properties of the menu are also taken into account. For example, when the direction is gtk.types.ArrowType.Down and the horizontal alignment is gtk.types.Align.Start, the menu will be positioned below the button, with the starting edge (depending on the text direction) of the menu aligned with the starting edge of the button. If there is not enough space below the button, the menu is popped up above the button instead. If the alignment would move part of the menu offscreen, it is “pushed in”.

Direction = Down

• halign = start

  

• halign = center

  

• halign = end

  

Direction = Up

• halign = start

  

• halign = center

  

• halign = end

  

Direction = Left

• valign = start

  

• valign = center

  

• valign = end

  

Direction = Right

• valign = start

  

• valign = center

  

• valign = end

  

CSS nodes

GtkMenuButton has a single CSS node with name button. To differentiate it from a plain #GtkButton, it gets the .popup style class.