I like this package. I have a few comments though:
- I think the name doesn't really reflect the nature of the dialog. I think Gtk2_EntryDialog would be more descriptive.
- I know you are trying to stick with the PHP-GTK 2 method names but I think you should have method aliases for some of the methods. For example, I think set_default_response should have an alias that is more PEAR-ish: setDefaultResponse(). It will help maintain consistency among PEAR packages and make using the package less confusing for developers.
- In the get() method, you set $text = null; if the user cancels the dialog. I think if the user clicks the OK button without putting a value in the text entry, the value returned will be null. That can lead to some confusing results. I think it is better to set the value to false if the user cancels the dialog. It is not possible for the user to set the value to a boolean false. That way I can run:
if (Gtk2_InputDialog::get(...) !== false) { ... }