Sets whether the progress bar will show a text in addition to the bar itself.
The shown text is either the value of the gtk.progress_bar.ProgressBar.text property or, if that is null, the gtk.progress_bar.ProgressBar.fraction value, as a percentage.
To make a progress bar that is styled and sized suitably for showing text (even if the actual text is blank), set property@Gtk.ProgressBar:show-text to true and gtk.progress_bar.ProgressBar.text to the empty string (not null).
Set showText property.