gtk:native-dialog-modal (object)

object -- a gtk:native-dialog object
modal -- true if the dialog is modal

The accessor for the modal slot gets whether the dialog is modal, or sets a dialog modal or non-modal. Modal dialogs prevent interaction with other windows in the same application. To keep modal dialogs on top of main application windows, use the gtk:native-dialog-transient-for function to make the dialog transient for the parent. Most window managers will then disallow lowering the dialog below the parent.