The preferred place to ellipsize the string.
The text will be ellipsized if the progress bar does not have enough room
to display the entire string, specified as a
Note that setting this property to a value other than
PANGO_ELLIPSIZE_NONE has the side-effect that the progress bar requests
only enough space to display the ellipsis (“…”). Another means to set a
progress bar’s width is gtk_widget_set_size_request().