Un-tabify three QDockWidgets programmatically

Question

I have an application with three dock widgets. Those are created by the following code:

dock = new QDockWidget(tr("Some title"));
dock->setWidget(some_widget);
dock->setContextMenuPolicy(Qt::PreventContextMenu);
dock->setFeatures(QDockWidget::DockWidgetMovable | QDockWidget::DockWidgetFloatable);
addDockWidget(Qt::TopDockWidgetArea, dock);

dock2 and dock3 are then tabified by

tabifyDockWidget(dock1, dock2);
tabifyDockWidget(dock2, dock3);

The window then looks like this:

I can arrange the docks side by side by dragging and dropping them, so that the window looks like this:

I'd like to do this programmatically, but I can't figure out how. When doing a

splitDockWidget(dock1, dock2, Qt::Horizontal);

nothing happens. When doing

splitDockWidget(dock1, dock2, Qt::Vertical);

dock1 and dock2 disappear, and only dock3 is still visible:

After manually dragging it out of the main window and back in, the window looks like this:

So what am I doing wrong here?

Answer 1

I found the solution. The problem is to which dockarea the docks are attached to. I added

setDockNestingEnabled(true);

and the following fuctions, which do the job by first changing the dockarea if needed:

void MainWindow::attachDocks(Qt::DockWidgetArea area)
{
    m_playersDock->setFloating(false);
    m_scoreDock->setFloating(false);
    m_rankingDock->setFloating(false);
    addDockWidget(area, m_playersDock);
    addDockWidget(area, m_scoreDock);
    addDockWidget(area, m_rankingDock);
}

void MainWindow::arrangeTabified()
{
    attachDocks(Qt::TopDockWidgetArea);
    tabifyDockWidget(m_playersDock, m_scoreDock);
    tabifyDockWidget(m_scoreDock, m_rankingDock);
}

void MainWindow::arrangeHorizontally()
{
    attachDocks(Qt::TopDockWidgetArea);
    splitDockWidget(m_playersDock, m_scoreDock, Qt::Horizontal);
    splitDockWidget(m_scoreDock, m_rankingDock, Qt::Horizontal);
}

void MainWindow::arrangeVertically()
{
    attachDocks(Qt::LeftDockWidgetArea);
    splitDockWidget(m_playersDock, m_scoreDock, Qt::Vertical);
    splitDockWidget(m_scoreDock, m_rankingDock, Qt::Vertical);
}

void MainWindow::arrangeOwnWindow()
{
    m_playersDock->setFloating(true);
    m_scoreDock->setFloating(true);
    m_rankingDock->setFloating(true);
}