Method CollapseSubTree

Views/Infovis/vtkDendrogramItem.cxx:938–982

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//------------------------------------------------------------------------------
void vtkDendrogramItem::CollapseSubTree(vtkIdType vertex)
{
  // no removing the root of the tree
  vtkIdType root = this->PrunedTree->GetRoot();
  if (vertex == root)
  {
    return;
  }

  // look up the original ID of the vertex that's being collapsed.
  vtkIdTypeArray* originalIdArray =
    vtkArrayDownCast<vtkIdTypeArray>(this->PrunedTree->GetVertexData()->GetArray("OriginalId"));
  vtkIdType originalId = originalIdArray->GetValue(vertex);

  // use this value as the index to the original (un-reindexed) tree's
  // "VertexIsPruned" array.  Mark that vertex as pruned by recording
  // how many collapsed leaf nodes exist beneath it.
  int numLeavesCollapsed = this->CountLeafNodes(originalId);

  // make sure we're not about to collapse away the whole tree
  int totalLeaves = this->CountLeafNodes(root);
  if (numLeavesCollapsed >= totalLeaves)
  {
    return;
  }

  // no collapsing of leaf nodes.  This should never happen, but it doesn't
  // hurt to be safe.
  if (numLeavesCollapsed == 0)
  {
    return;
  }

  vtkUnsignedIntArray* vertexIsPruned =
    vtkArrayDownCast<vtkUnsignedIntArray>(this->Tree->GetVertexData()->GetArray("VertexIsPruned"));
  vertexIsPruned->SetValue(originalId, numLeavesCollapsed);

  vtkNew<vtkTree> prunedTreeCopy;
  prunedTreeCopy->ShallowCopy(this->PrunedTree);

  this->PruneFilter->SetInputData(prunedTreeCopy);
  this->PruneFilter->SetParentVertex(vertex);
  this->PruneFilter->Update();
  this->PrunedTree = this->PruneFilter->GetOutput();
}

//------------------------------------------------------------------------------
void vtkDendrogramItem::ExpandSubTree(vtkIdType vertex)