Multiple Inheritance Example

CalculatorForm Implementation

In the constructor, we call setupUi() to load the user interface file. Note that we do not need the ui prefix as CalculatorForm is a subclass of the user interface class.

 CalculatorForm::CalculatorForm(QWidget *parent)
     : QWidget(parent)
 {
     setupUi(this);
 }

We include two slots, on_inputSpinBox1_valueChanged() and on_inputSpinBox2_valueChanged(). These slots respond to the valueChanged() signal that both spin boxes emit. Whenever there is a change in one spin box's value, we take that value and add it to whatever value the other spin box has.

 void CalculatorForm::on_inputSpinBox1_valueChanged(int value)
 {
     outputWidget->setText(QString::number(value + inputSpinBox2->value()));
 }

 void CalculatorForm::on_inputSpinBox2_valueChanged(int value)
 {
     outputWidget->setText(QString::number(value + inputSpinBox1->value()));
 }

 int main(int argc, char *argv[])
 {
     QApplication app(argc, argv);
     CalculatorForm calculator;
     calculator.show();
     return app.exec();
 }