#include <QtWidgets>

class TreeWidget : public QTreeWidget {
    Q_OBJECT

public:
    TreeWidget(QWidget *parent = 0) : QTreeWidget(parent) {
        initialize();
    }

    void initialize() {

        setDragEnabled(true);

        setColumnCount(2);

        QList<QTreeWidgetItem *> items;
        for (int i = 0; i < 10; ++i) {
            QTreeWidgetItem *item = new QTreeWidgetItem();
            for (int j = 0; j < columnCount(); ++j) {
                item->setText(j, QString("item: %1:%2").arg(i).arg(j));
            }
            items.append(item);
        }

        addTopLevelItems(items);

        for(int i = 0; i < columnCount(); i++ ) {
            resizeColumnToContents(i);
        }
    }

public slots:

    void hideHeader() {
        setColumnHidden(0, true);
    }

    void moveHeader() {
        header()->moveSection(0, 1);
    }

};

class Foo : public QWidget {
    Q_OBJECT

    TreeWidget *_treeWidget;

public:

    Foo() : QWidget(0) {

        QVBoxLayout *lay = new QVBoxLayout(this);

        _treeWidget = new TreeWidget;
        QPushButton *button = new QPushButton("hide");
        QPushButton *button2 = new QPushButton("move");

        lay->addWidget(_treeWidget);
        lay->addWidget(button);
        lay->addWidget(button2);

        connect(button, SIGNAL(clicked()), this, SLOT(didClickHide()));
        connect(button2, SIGNAL(clicked()), this, SLOT(didClickMove()));
    }

private slots:

    void didClickHide() {
        _treeWidget->hideHeader();
    }

    void didClickMove() {
        _treeWidget->moveHeader();
    }

};

int main(int argc, char *argv[]) {

    QApplication app(argc, argv);

    Foo w;
    w.show();

    return app.exec();
}

#include "main.moc"