gtk:tree-view-hover-expand (object)

object -- a gtk:tree-view widget
expand -- true to enable hover selection mode

The accessor for the hover-expand slot of the gtk:tree-view class gets or sets whether hover expansion mode is turned on for the tree view. Hover expansion makes rows expand or collapse if the pointer moves over them. The gtk:tree-view implementation is deprecated since 4.10. Please do not use it in newly written code.