gtk/gtk.go
func (v *FileChooser) SetPreviewWidget(widget IWidget) {
	C.gtk_file_chooser_set_preview_widget(v.native(), widget.toWidget())
}
func (v *FileChooser) SetPreviewWidget(widget IWidget) {
	C.gtk_file_chooser_set_preview_widget(v.native(), widget.toWidget())
}
// SetPreviewWidget is a wrapper around gtk_file_chooser_set_preview_widget().