<para>The <seecref="M:Gtk.PrintOperation.CreateCustomWidget"/> event invokes <seecref="T:Gtk.CreateCustomWidgetHandler"/> delegates which pass event data via this class.</para>
<para>If you set the <seecref="M:GLib.SignalArgs.RetVal"/> to a <seecref="Gtk.Widget"/> in an event handler, the specified widget will be added to a custom tab in the print dialog.</para>
<remarks>Create a new <seecref="T:Gtk.CreateCustomWidgetArgs"/> instance with this constructor if you need to invoke a <seecref="T:Gtk.CreateCustomWidgetHandler"/> delegate.</remarks>