gtk:editable-enable-undo (object)

object -- a gtk:editable widget
setting -- a boolean whether undo is enabled

The accessor for the enable-undo slot gets or sets whether undo/redo actions are enabled for the editable widget. If enabled, changes to the editable widget will be saved for undo/redo actions. This results in an additional copy of text changes and are not stored in secure memory. As such, undo is forcefully disabled when the visibility property of the gtk:text widget is set to false.