Method applyPanLayout

src/gui/MainWindow.cpp:7699–7757

}

void MainWindow::applyPanLayout(const QString& layoutId)
{
    if (!m_radioModel.isConnected()) return;

    const int needed = panCountForLayoutId(layoutId);
    const int existing = m_panStack->count();

    if (needed < existing) {
        qDebug() << "applyPanLayout: reducing from" << existing << "to" << needed << "pans";

        // Close extra pans from the end (keep the first N)
        auto allApplets = m_panStack->allApplets();
        int toRemove = existing - needed;
        for (int i = allApplets.size() - 1; i >= 0 && toRemove > 0; --i) {
            auto* applet = allApplets[i];
            QString panId = applet->panId();
            if (panId == "default") continue;
            qDebug() << "applyPanLayout: closing pan" << panId;
            // Route through removePanadapter so a layout-shrink tears down the
            // waterfall too ("display pan remove" + "display panafall remove"),
            // not just the panadapter stream. (#3843)
            m_radioModel.removePanadapter(panId);
            // Radio will send "removed" status → panadapterRemoved signal
            // → PanadapterStack::removePanadapter()
            --toRemove;
        }

        // Rearrange remaining pans after a short delay for radio to process
        QTimer::singleShot(500, this, [this, layoutId]() {
            m_panStack->rearrangeLayout(layoutId);
        });
        return;
    }
    if (needed == existing) {
        // Same count, just rearrange
        m_panStack->rearrangeLayout(layoutId);
        return;
    }

    // Create additional pans to reach the needed count.
    // Keep existing pan(s) alive — no tear-down, no dangling signals.
    const int currentSliceCount = static_cast<int>(m_radioModel.slices().size());
    if (currentSliceCount >= m_radioModel.maxSlices()) {
        showPanadapterSliceCapacityMessage();
        return;
    }

    const int toCreate = needed - existing;
    auto panIds = std::make_shared<QStringList>();

    // Collect existing pan IDs first (they'll be part of the layout)
    for (auto* applet : m_panStack->allApplets())
        panIds->append(applet->panId());

    qDebug() << "applyPanLayout: have" << existing << "pans, creating"
             << toCreate << "more for layout" << layoutId;

    createPansSequentially(layoutId, toCreate, panIds, 0);