Method dropMimeData

Modules/QtWidgets/src/QmitkDataStorageTreeModel.cpp:143–367

}

bool QmitkDataStorageTreeModel::dropMimeData(
  const QMimeData *data, Qt::DropAction action, int row, int /*column*/, const QModelIndex &parent)
{
  // Early exit, returning true, but not actually doing anything (ignoring data).
  if (action == Qt::IgnoreAction)
  {
    return true;
  }

  // Note, we are returning true if we handled it, and false otherwise
  bool returnValue = false;

  if (data->hasFormat("application/x-qabstractitemmodeldatalist"))
  {
    returnValue = true;

    // First we extract a Qlist of TreeItem* pointers.
    QList<TreeItem *> listOfItemsToDrop = ToTreeItemPtrList(data);
    if (listOfItemsToDrop.empty())
    {
      return false;
    }

    // Retrieve the TreeItem* where we are dropping stuff, and its parent.
    TreeItem *dropItem = this->TreeItemFromIndex(parent);
    TreeItem *parentItem = dropItem->GetParent();

    // If item was dropped onto empty space, we select the root node
    if (dropItem == m_Root)
    {
      parentItem = m_Root;
    }

    // Dragging and Dropping is only allowed within the same parent, so use the first item in list to validate.
    // (otherwise, you could have a derived image such as a segmentation, and assign it to another image).
    // NOTE: We are assuming the input list is valid... i.e. when it was dragged, all the items had the same parent.

    // Determine whether or not the drag and drop operation is a valid one.
    // Examples of invalid operations include:
    //  - dragging nodes with different parents
    //  - dragging nodes from one parent to another parent, if m_AllowHierarchyChange is false
    //  - dragging a node on one of its child nodes (only relevant if m_AllowHierarchyChange is true)

    bool isValidDragAndDropOperation(true);

    // different parents
    {
      TreeItem *firstParent = listOfItemsToDrop[0]->GetParent();
      QList<TreeItem *>::iterator diIter;
      for (diIter = listOfItemsToDrop.begin() + 1; diIter != listOfItemsToDrop.end(); diIter++)
      {
        if (firstParent != (*diIter)->GetParent())
        {
          isValidDragAndDropOperation = false;
          break;
        }
      }
    }