Sets whether the contents of the `GtkText` are visible or not.
When visibility is set to false, characters are displayed as the invisible char, and will also appear that way when the text in the widget is copied to the clipboard.
By default, GTK picks the best invisible character available in the current font, but it can be changed with [ [email protected]_invisible_char].
Note that you probably want to set [[email protected]:input-purpose] to gtk_input_purpose_password or gtk_input_purpose_pin to inform input methods about the purpose of this self, in addition to setting visibility to false.
| this |
a `GtkText` |
| visible |
true if the contents of the `GtkText` are displayed as plaintext |