Entry.setPlaceholderText

Sets text to be displayed in entry when it is empty and unfocused. This can be used to give a visual hint of the expected contents of the #GtkEntry.

Note that since the placeholder text gets removed when the entry received focus, using this feature is a bit problematic if the entry is given the initial focus in a window. Sometimes this can be worked around by delaying the initial focus setting until the first key event arrives.