CBaseList Class (Compact 2013)

3/26/2014

CBaseObject Class

     CBaseList Class

This class represents a list of pointers to objects. No storage management or copying is done on the objects that are pointed to.

The implementation allows for objects to be on multiple lists simultaneously and does not require support in the objects themselves. Therefore, it is particularly useful for holding variable-length lists of interface pointers.

The implementation is not multithread safe. External locks are required to maintain the integrity of the list when it is accessed from more than one thread simultaneously.

The POSITION structure represents a position in a linked list that is a void pointer.

A position represents a cursor on the list that can be set to identify any element.

NULL is a valid value, and several operations regard NULL as the position that is one step off the end of the list. (In an n element list there are n+1 places to insert, and NULL is that n+1 value.)

The position of an element in the list is only invalidated if that element is deleted. Move operations might indicate that what was a valid position in one list is now a valid position in a different list.

Some operations, which at first sight seem illegal, are allowed as harmless null operations (no-ops).

For example, the CBaseList::RemoveHeadI member function is legal on an empty list, and it returns NULL. This allows an atomic way to test if there is an element there and, if so, to retrieve it.

Single-element operations return positions, where a non-NULL value indicates that it worked.

Entire list operations return a Boolean value, where TRUE indicates success.

Protected Data Members

Member	Description
m_Count	Number of nodes in the list.
m_pFirst	Pointer to the first node in the list.
m_pLast	Pointer to the last node in the list.

Member Functions

Member function	Description
AddAfter	Inserts a list of nodes after the specified node.
AddAfterI	Inserts a node after the specified node.
AddBefore	Inserts a list of nodes before the specified node.
AddBeforeI	Inserts a node before the specified node.
AddHead	Inserts a list of nodes at the front of the list.
AddHeadI	Inserts a node at the front of the list.
AddTail	Appends a list of nodes to the end of the list.
AddTailI	Appends a node to the end of the list.
CBaseList	Constructs a CBaseList object.
FindI	Returns the first position that holds the specified object.
GetCountI	Returns the number of objects in the list.
GetHeadPositionI	Returns a cursor identifying the first element of the list.
GetI	Returns the object at the specified position.
GetNextI	Returns the specified object and updates the position.
GetTailPositionI	Returns a cursor identifying the last element of the list.
MoveToHead	Moves the node or list of nodes to the beginning of a second list.
MoveToTail	Moves the node or list of nodes to the end of a second list.
Next	Returns the next position in the list.
Prev	Returns the previous position in the list.
RemoveAll	Removes all nodes from the list.
RemoveHeadI	Removes the first node in the list.
RemoveI	Removes the specified node from the list.
RemoveTailI	Removes the last node in the list.
Reverse	Reverses the order of the pointers to the objects in the list.

Requirements

Header	dshow.h, Streams.h
Library	ole32.lib, Ole32auth.lib, Strmbase.lib, Strmiids.lib, uuid.lib

See Also

Reference

DirectShow Classes