CObList Class

Article
01/08/2013

Supports ordered lists of nonunique CObject pointers accessible sequentially or by pointer value.

class CObList : public CObject

Members

Public Constructors

Name	Description
CObList::CObList	Constructs an empty list for CObject pointers.

Public Methods

Name	Description
CObList::AddHead	Adds an element (or all the elements in another list) to the head of the list (makes a new head).
CObList::AddTail	Adds an element (or all the elements in another list) to the tail of the list (makes a new tail).
CObList::Find	Gets the position of an element specified by pointer value.
CObList::FindIndex	Gets the position of an element specified by a zero-based index.
CObList::GetAt	Gets the element at a given position.
CObList::GetCount	Returns the number of elements in this list.
CObList::GetHead	Returns the head element of the list (cannot be empty).
CObList::GetHeadPosition	Returns the position of the head element of the list.
CObList::GetNext	Gets the next element for iterating.
CObList::GetPrev	Gets the previous element for iterating.
CObList::GetSize	Returns the number of elements in this list.
CObList::GetTail	Returns the tail element of the list (cannot be empty).
CObList::GetTailPosition	Returns the position of the tail element of the list.
CObList::InsertAfter	Inserts a new element after a given position.
CObList::InsertBefore	Inserts a new element before a given position.
CObList::IsEmpty	Tests for the empty list condition (no elements).
CObList::RemoveAll	Removes all the elements from this list.
CObList::RemoveAt	Removes an element from this list, specified by position.
CObList::RemoveHead	Removes the element from the head of the list.
CObList::RemoveTail	Removes the element from the tail of the list.
CObList::SetAt	Sets the element at a given position.

Remarks

CObList lists behave like doubly-linked lists.

A variable of type POSITION is a key for the list. You can use a POSITION variable both as an iterator to traverse a list sequentially and as a bookmark to hold a place. A position is not the same as an index, however.

Element insertion is very fast at the list head, at the tail, and at a known POSITION. A sequential search is necessary to look up an element by value or index. This search can be slow if the list is long.

CObList incorporates the IMPLEMENT_SERIAL macro to support serialization and dumping of its elements. If a list of CObject pointers is stored to an archive, either with an overloaded insertion operator or with the Serialize member function, each CObject element is serialized in turn.

If you need a dump of individual CObject elements in the list, you must set the depth of the dump context to 1 or greater.

When a CObList object is deleted, or when its elements are removed, only the CObject pointers are removed, not the objects they reference.

You can derive your own classes from CObList. Your new list class, designed to hold pointers to objects derived from CObject, adds new data members and new member functions. Note that the resulting list is not strictly type safe, because it allows insertion of any CObject pointer.

Note

You must use the IMPLEMENT_SERIAL macro in the implementation of your derived class if you intend to serialize the list.

For more information on using CObList, see the article Collections.

Inheritance Hierarchy

CObject

CObList

Requirements

Header: afxcoll.h