Increment and decrement GtkObject references

Description

This allows the R programmer to explicitly increment and decrement the references to a GtkObject. This is useful, indeed necessary, if one needs to ensure that a particular GtkObject needs to exist even if it would be garbage collected by Gtk's own reference mechanism. For example, if we remove a GtkWidget from a GUI but want to use it later, we should increase the reference count by 1 before removing it and decrement it after we have added it to the new GUI.

Usage

gtkObjectRef(obj)
gtkObjectUnref(obj)

Arguments

Details

These functions are direct interfaces to the gtk_object_ref and gtk_object_unref routines in the Gtk library.

Value

Author(s)

Duncan Temple Lang <duncan@research.bell-labs.com>

References

Information on the package is available from http://www.omegahat.org/RGtk.

Information on Gtk is available from http://www.gtk.org.

See Also

gtkContainerRemove

Examples

## Not run: 
 win = gtkWindow()
 b1 = gtkButton("A button")
 b2 = gtkButton("Another button")

 b1$Ref()
 b2$Ref()

 b1$AddCallback("clicked",
                   function(b, w)  {
                      win$Remove(w)
                      win$Add(b)
                   }, b2)
 b2$AddCallback("clicked",
                   function(b, w)  {
                      win$Remove(w)
                      win$Add(b)
                   }, b1)

 win$AddCallback("destroy",
                  function(obj) {
                    b1$Unref()
                    b2$Unref()
                  })
## End(Not run)