Method onProgressiveLayoutDrained

pj_app/src/MainWindow.cpp:2982–3036

}

void MainWindow::onProgressiveLayoutDrained() {
  QObject::disconnect(pending_items_added_conn_);
  pending_items_added_conn_ = {};

  if (pending_binder_ != nullptr) {
    static_cast<void>(pending_binder_->flush({}));
    // Frame each restored plot to its layout-saved window with the now-settled display
    // offset (the file has finished loading). This previously called zoomOut because the
    // saved range was display-relative and the save vs reload offsets could differ; PR
    // #248 made the saved X ABSOLUTE and applySavedViewportOrZoom converts it with the
    // live offset, so re-applying it is correct — and it pins the plot to its final
    // window so data fills in like streaming rather than the axis auto-fitting/growing.
    // Plots with no/degenerate saved range fall back to zoomOut; clear_after drops the
    // one-shot stash. Still under the in-flight gate, so onUndoableChange stays
    // suppressed until the single snapshot below.
    forEachPlot([](PlotWidget* plot) { plot->applySavedViewportOrZoom(/*clear_after=*/true); });

    QStringList shown;
    QSet<QString> seen;
    for (const layout_xml::SeriesPath& path : pending_binder_->unresolved()) {
      const QString display = path.display();
      if (!display.isEmpty() && !seen.contains(display)) {
        seen.insert(display);
        shown.push_back(display);
      }
    }
    if (!shown.isEmpty()) {
      switch (promptMissingCurves(shown)) {
        case MissingCurveChoice::kRemove:
          break;  // Remaining curves were never bound, so there is nothing to strip from live widgets.
        case MissingCurveChoice::kCancel:
          // The reload has already mutated the live session, so progressive restore is non-transactional:
          // leave the partial layout in place instead of rolling back to a stale pre-load snapshot.
          break;
      }
    }
    pending_binder_->clear();
  }

  retryPendingSceneRestores({});
  broadcastTrackerTime(toAxisDouble(session_->playbackEngine().currentTime()));
  const QStringList unresolved_scenes = unresolvedPendingSceneRestores();
  if (!unresolved_scenes.isEmpty()) {
    emitDiagnostic(
        DiagnosticLevel::kWarning, "Layout", "scene_restore_pending",
        tr("%n scene layer(s) could not be rebound after progressive load.", nullptr,
           static_cast<int>(unresolved_scenes.size())));
  }
  clearPendingSceneRestores();

  QObject::disconnect(pending_queue_drained_conn_);
  pending_queue_drained_conn_ = {};
  progressive_layout_in_flight_ = false;
  pushUndoState(/*force_new_state=*/true);
}

void MainWindow::saveLayoutToPath(const QString& path, bool include_data_source) {
  QDomDocument doc = xmlSaveState();