Method mousePressEvent

pj_widgets/src/CurveTreeView.cpp:768–806

}

void CurveTreeView::mousePressEvent(QMouseEvent* event) {
  drag_curve_names_.clear();
  drag_catalog_keys_.clear();
  suppress_next_release_ = false;
  drag_button_ = Qt::NoButton;
  if (event->button() == Qt::LeftButton || event->button() == Qt::RightButton) {
    QTreeWidgetItem* item = itemAt(event->pos());
    // Only draggable rows (curve leaves / object topics) initiate a drag or the
    // drag-the-whole-selection gesture. Non-draggable rows — notably the selectable
    // dataset groups — fall straight through to the base handler, so plain/Ctrl/Shift
    // selection and expand/collapse behave normally and a dataset never starts a drag.
    const bool draggable = item != nullptr && (item->flags() & Qt::ItemIsDragEnabled);
    if (draggable) {
      drag_start_pos_ = event->pos();
      drag_button_ = event->button();

      const Qt::KeyboardModifiers selection_modifiers = Qt::ControlModifier | Qt::ShiftModifier | Qt::MetaModifier;
      const QString item_catalog_key = catalogKeyForItem(item);
      if (!item_catalog_key.isEmpty()) {
        drag_catalog_keys_.push_back(item_catalog_key);
      }
      if (item->isSelected() && !(event->modifiers() & selection_modifiers)) {
        drag_curve_names_ = selectedCurveNamesForDrag();
        // A plain press on an already-selected row drags the WHOLE selection.
        // Preserve it (suppress the release that would otherwise collapse it to
        // the clicked row) whenever more than one row is selected — counting
        // object/image topics too, which contribute catalog keys but no scalar
        // curve names. The payload itself is read back from the live selection in
        // createDragMimeData(), so it stays correct as long as we keep it intact.
        if (drag_curve_names_.size() > 1 || selectedCatalogKeysRecursive().size() > 1) {
          suppress_next_release_ = true;
          event->accept();
          return;
        }
      }
    }
  }
  QTreeWidget::mousePressEvent(event);
}

void CurveTreeView::mouseMoveEvent(QMouseEvent* event) {
  if (drag_button_ == Qt::NoButton) {