Russian Qt Forum

#include <QtCore>
#include <QtGui>

class One : public QWidget
{
    Q_OBJECT
public:
    One(QWidget *parent = 0);
public slots:
    void slot_turn();
signals:
    void turn();
};

class Two : public QWidget
{
    Q_OBJECT
public:
    Two(QWidget *parent = 0);
public slots:
    void slot_turn();
signals:
    void turn();
};

class All : public QWidget
{
    Q_OBJECT
private:
    enum Mode {OneMode, TwoMode};
    Mode mode;
    One *w_one;
    Two *w_two;
public:
    All(QWidget *parent = 0);
public slots:
    void slot_turn();
};

One::One(QWidget *parent)
    : QWidget(parent)
{
    // widget
    QLabel *lbl = new QLabel("One");
    lbl->setMargin(20);

    QPushButton *btn = new QPushButton("Turn");

    // layout
    QVBoxLayout *all = new QVBoxLayout;
    all->addWidget(lbl);
    all->addWidget(btn);

    setLayout(all);

    // signals and slots
    QObject::connect(btn, SIGNAL(released()),
                     this, SLOT(slot_turn()));
}

void One::slot_turn()
{
    emit turn();
}


Two::Two(QWidget *parent)
    : QWidget(parent)
{
    // widget
    QLabel *lbl = new QLabel("Two");
    lbl->setMargin(20);

    QPushButton *btn = new QPushButton("Turn");

    // layout
    QVBoxLayout *all = new QVBoxLayout;
    all->addWidget(lbl);
    all->addWidget(btn);

    setLayout(all);

    // signals and slots
    QObject::connect(btn, SIGNAL(released()),
                     this, SLOT(slot_turn()));
}

void Two::slot_turn()
{
    emit turn();
}


All::All(QWidget *parent)
    : QWidget(parent)
{
    mode = OneMode;

    // widget
    w_one = new One;
    w_two = new Two;

    // layout
    QVBoxLayout *all = new QVBoxLayout;
    all->addWidget(w_one);

    setLayout(all);

    // signals and slots
    QObject::connect(w_one, SIGNAL(turn()),
                     this, SLOT(slot_turn()));
    QObject::connect(w_two, SIGNAL(turn()),
                     this, SLOT(slot_turn()));
}

void All::slot_turn()
{
    if (sender() == w_one) {
        mode = TwoMode;
        layout()->removeWidget(w_one);
        layout()->addWidget(w_two);
    } else {
        mode = OneMode;
        layout()->removeWidget(w_two);
        layout()->addWidget(w_one);
    }
    repaint();
}