Method tailFrames

app/src/API/Handlers/DashboardHandler.cpp:457–520

* @brief Returns the last N samples of every plot-enabled dataset. */

 * @brief Returns the last N samples of every plot-enabled dataset.
 */
API::CommandResponse API::Handlers::DashboardHandler::tailFrames(const QString& id,
                                                                 const QJsonObject& params)
{
  int count = 32;
  if (params.contains(QStringLiteral("count")))
    count = qBound(1, params.value(QStringLiteral("count")).toInt(32), 256);

  QSet<int> filterUids;
  bool filterActive = false;
  if (params.contains(QStringLiteral("uniqueIds"))) {
    const auto arr = params.value(QStringLiteral("uniqueIds")).toArray();
    for (const auto& v : arr)
      filterUids.insert(v.toInt());

    filterActive = !filterUids.isEmpty();
  }

  auto& dashboard     = UI::Dashboard::instance();
  const int plotCount = dashboard.widgetCount(SerialStudio::DashboardPlot);
  QJsonArray seriesArr;

  for (int i = 0; i < plotCount; ++i) {
    const auto& ds = dashboard.getDatasetWidget(SerialStudio::DashboardPlot, i);
    if (filterActive && !filterUids.contains(ds.uniqueId))
      continue;

    const auto& series = dashboard.plotData(i);
    if (!series.x || !series.y)
      continue;

    const auto& xq = *series.x;
    const auto& yq = *series.y;
    const auto n   = std::min<std::size_t>(xq.size(), yq.size());
    if (n == 0)
      continue;

    const std::size_t take  = std::min<std::size_t>(static_cast<std::size_t>(count), n);
    const std::size_t start = n - take;

    QJsonArray xs;
    QJsonArray ys;
    for (std::size_t k = start; k < n; ++k) {
      xs.append(xq[k]);
      ys.append(yq[k]);
    }

    QJsonObject row;
    row[Keys::UniqueId]            = ds.uniqueId;
    row[QStringLiteral("title")]   = ds.title;
    row[QStringLiteral("units")]   = ds.units;
    row[QStringLiteral("groupId")] = ds.groupId;
    row[Keys::DatasetId]           = ds.datasetId;
    row[QStringLiteral("count")]   = static_cast<int>(take);
    row[QStringLiteral("x")]       = xs;
    row[QStringLiteral("y")]       = ys;
    seriesArr.append(row);
  }