Method nextActiveWindow

app/src/UI/Taskbar.cpp:322–355

* @brief Returns the next/previous non-closed window in taskbar order. */

 * @brief Returns the next/previous non-closed window in taskbar order.
 */
QQuickItem* UI::Taskbar::nextActiveWindow(int delta) const
{
  if (!m_taskbarButtons || delta == 0)
    return nullptr;

  QList<QQuickItem*> windows;
  windows.reserve(m_taskbarButtons->rowCount());
  for (int i = 0; i < m_taskbarButtons->rowCount(); ++i) {
    auto* row = m_taskbarButtons->item(i);
    if (!row)
      continue;

    const int wid = row->data(TaskbarModel::WindowIdRole).toInt();
    auto* win     = windowData(wid);
    if (!win)
      continue;

    const auto state =
      static_cast<TaskbarModel::WindowState>(row->data(TaskbarModel::WindowStateRole).toInt());
    if (state == TaskbarModel::WindowClosed)
      continue;

    windows.append(win);
  }

  if (windows.isEmpty())
    return nullptr;

  const int currentIdx = windows.indexOf(m_activeWindow);
  const int n          = windows.size();
  const int base       = currentIdx >= 0 ? currentIdx : (delta > 0 ? -1 : 0);
  const int nextIdx    = ((base + delta) % n + n) % n;
  return windows.at(nextIdx);
}

/**
 * @brief Serializes the active group's layout and writes it to the project file;