geo::ROOTGeoNodeForwardIterator Class Reference

Iterator to navigate through all the nodes. More...

#include <GeometryCore.h>

Classes
struct	NodeInfo_t

Public Member Functions
	ROOTGeoNodeForwardIterator (TGeoNode const *start_node)
	Constructor: start from this node. More...
TGeoNode const *	operator* () const
	Returns the pointer to the current node, or nullptr if none. More...
ROOTGeoNodeForwardIterator &	operator++ ()
	Points to the next node, or to nullptr if there are no more. More...
std::vector< TGeoNode const * >	get_path () const
	Returns the full path of the current node. More...

Protected Types
using	Node_t = TGeoNode const *

Protected Member Functions
void	reach_deepest_descendant ()
void	init (TGeoNode const *start_node)

Protected Attributes
std::vector< NodeInfo_t >	current_path
	which node, which sibling? More...

Detailed Description

Iterator to navigate through all the nodes.

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Note that this is not a fully standard forward iterator in that it lacks of the postfix operator. The reason is that it's too expensive and it should be avoided. Also I did not bother declaring the standard type definitions (that's just laziness).

An example of iteration:

TGeoNode const* pCurrentNode;

ROOTGeoNodeForwardIterator iNode(geom->ROOTGeoManager()->GetTopNode());
while ((pCurrentNode = *iNode)) {
  // do something with pCurrentNode
  ++iNode;
} // while

These iterators are one use only, and they can't be reset after a loop is completed.

Definition at line 5590 of file GeometryCore.h.

Member Typedef Documentation

using geo::ROOTGeoNodeForwardIterator::Node_t = TGeoNode const*

protected

Definition at line 5607 of file GeometryCore.h.

Constructor & Destructor Documentation

geo::ROOTGeoNodeForwardIterator::ROOTGeoNodeForwardIterator ( TGeoNode const *  start_node )

inline

Constructor: start from this node.

Definition at line 5593 of file GeometryCore.h.

      { init(start_node); }

Member Function Documentation

std::vector< TGeoNode const * > geo::ROOTGeoNodeForwardIterator::get_path

(

)

const

Returns the full path of the current node.

Definition at line 1957 of file GeometryCore.cxx.

                                                                        {

    std::vector<TGeoNode const*> node_path(current_path.size());

    std::transform(current_path.begin(), current_path.end(), node_path.begin(),
      [](NodeInfo_t const& node_info){ return node_info.self; });
    return node_path;

  } // ROOTGeoNodeForwardIterator::path()

void geo::ROOTGeoNodeForwardIterator::init ( TGeoNode const *  start_node )

protected

Definition at line 1978 of file GeometryCore.cxx.

                                                                  {
    current_path.clear();
    if (!start_node) return;
    current_path.emplace_back(start_node, 0U);
    reach_deepest_descendant();
  } // ROOTGeoNodeForwardIterator::init()

TGeoNode const* geo::ROOTGeoNodeForwardIterator::operator* ( ) const

inline

Returns the pointer to the current node, or nullptr if none.

Definition at line 5597 of file GeometryCore.h.

      { return current_path.empty()? nullptr: current_path.back().self; }

ROOTGeoNodeForwardIterator & geo::ROOTGeoNodeForwardIterator::operator++

(

)

Points to the next node, or to nullptr if there are no more.

Definition at line 1938 of file GeometryCore.cxx.

                                                                      {
    if (current_path.empty()) return *this;
    if (current_path.size() == 1) { current_path.pop_back(); return *this; }

    // I am done; all my descendants were also done already;
    // first look at my younger siblings
    NodeInfo_t& current = current_path.back();
    NodeInfo_t const& parent = current_path[current_path.size() - 2];
    if (++(current.sibling) < parent.self->GetNdaughters()) {
      // my next sibling exists, let's parse his descendents
      current.self = parent.self->GetDaughter(current.sibling);
      reach_deepest_descendant();
    }
    else current_path.pop_back(); // no sibling, it's time for mum
    return *this;
  } // ROOTGeoNodeForwardIterator::operator++

void geo::ROOTGeoNodeForwardIterator::reach_deepest_descendant ( )

protected

Definition at line 1969 of file GeometryCore.cxx.

                                                            {
    Node_t descendent = current_path.back().self;
    while (descendent->GetNdaughters() > 0) {
      descendent = descendent->GetDaughter(0);
      current_path.emplace_back(descendent, 0U);
    } // while
  } // ROOTGeoNodeForwardIterator::reach_deepest_descendant()

Member Data Documentation

std::vector<NodeInfo_t> geo::ROOTGeoNodeForwardIterator::current_path

protected

which node, which sibling?

Definition at line 5615 of file GeometryCore.h.

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The documentation for this class was generated from the following files:

• larcorealg/larcorealg/Geometry/GeometryCore.h
• larcorealg/larcorealg/Geometry/GeometryCore.cxx