gistfile1.hpp

#include <QtGui/QApplication>
#include <QSplitter>
#include <QPushButton>

class QCustomSplitter : public QSplitter
{
    Q_OBJECT
public:
    QCustomSplitter(QWidget* parent = 0);
    QCustomSplitter(Qt::Orientation orient, QWidget* parent = 0);
    void SetSibling(QCustomSplitter* sibling);
public slots:
    void signalMoveSplitter(int posi, int index);
protected:
    QCustomSplitter* sibl;
    int pos;
};

class QSplitterFourWay : public QObject
{
public:
    QSplitterFourWay(QWidget* Parent = 0);
    QSplitter* mainSplitter();
    QSplitter* leftSplitter();
    QSplitter* rightSplitter();
    QSplitter *splitter;
    QCustomSplitter *left, *right;
};

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    MainWindow(QWidget *parent = 0);
    ~MainWindow();
private:
    QSplitterFourWay s;
};

QCustomSplitter::QCustomSplitter(QWidget* parent) : QSplitter(parent), pos(0){}
QCustomSplitter::QCustomSplitter(Qt::Orientation orient, QWidget* parent) : QSplitter(orient, parent), pos(0){}

void QCustomSplitter::SetSibling(QCustomSplitter* sibling){sibl = sibling;}

void QCustomSplitter::signalMoveSplitter(int posi, int index)
{
    if(this->pos == posi)
        return;
    Q_ASSERT(index == 1);
    this->pos = posi;
    moveSplitter(posi, index);
    return;
}


QSplitterFourWay::QSplitterFourWay(QWidget* parent) :
    splitter( new QSplitter(Qt::Horizontal, parent) ),
        left( new QCustomSplitter(Qt::Vertical, splitter) ),
            right( new QCustomSplitter(Qt::Vertical, splitter) )
{
    left->SetSibling(right);
    right->SetSibling(left);

    splitter->addWidget(left);
    splitter->addWidget(right);

    connect(left, SIGNAL(splitterMoved(int, int)), right, SLOT(signalMoveSplitter(int, int)));
    connect(right, SIGNAL(splitterMoved(int, int)), left, SLOT(signalMoveSplitter(int, int)));
}

QSplitter* QSplitterFourWay::mainSplitter(){ return splitter; }
QSplitter* QSplitterFourWay::leftSplitter(){ return left; }
QSplitter* QSplitterFourWay::rightSplitter(){ return right; }

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent), s(NULL)
{
    s = new QSplitterFourWay(this);
    QSplitter* top = s->mainSplitter();
    QSplitter* left = s->leftSplitter();
    QSplitter* right = s->rightSplitter();

    left->addWidget(new QPushButton("button1") );
    left->addWidget(new QPushButton("button2") );
    right->addWidget(new QPushButton("button3") );
    right->addWidget(new QPushButton("button4") );

    top->setMinimumSize(640, 480);
    top->setMaximumSize(800, 600);

    this->setMinimumSize(640, 480);
}

MainWindow::~MainWindow()
{
    if(s)
        delete s;
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    w.show();
    return a.exec();
}