There is a class
namespace Ui { class Base; } class Base : public QWidget { protected: Ui::Base* ui; public: explicit Base(QWidget* parent) :QWidget(parent), ui(new Ui::Base) { ui.setupUi(this); } } Well, respectively, somewhere in the base.ui file its interface is described. It is necessary to make a class that will inherit the interface of the Base class and it was possible to extend it in the designer.
How can I do that?