List2Dh Class Reference

class representing the list header in a linked list system More...

#include <list2d.h>

Public Member Functions
	List2Dh ()
	constructor;
virtual	~List2Dh ()
	destructor; will free resources;
void	erase (void)
	remove all items from this list by deleting them More...
void	setFirst (List2De *pNew)
	set first item
void	setCount (int iNew)
	set number of items
List2De *	first (void) const
	get first item
List2De *	last (void) const
	get last item
int	count (void) const
	get the number of items
bool	isEmpty (void) const
	the number of items is 0?
int	itemIndex (const List2De *pIt) const
	returns the index of a particular item inside this chain More...
bool	has (const List2De *pIt) const
	tell if an item is part of this chain
void	append (List2De *pIt)
	append an item (insert after last) More...
void	prepend (List2De *pIt)
	prepend an item (insert as first item) More...
void	insert (List2De *p_new, int index)
	insert a item at specified index More...
void	ackAdd (List2De *pNew)
	header is informed about an item being added More...
void	remove (int i)
	remove the item at given index More...
void	remove (List2De *pIt)
	remove a particular item More...
void	ackDel (List2De *pNew)
	header is informed about an item being deleted More...
void	dbgDump (void) const
	print the content of this object to debug output
bool	contains (const List2De *p_el) const
	tell if this list contains an entry
List2De *	item (int i) const
List2De *	at (int i) const
List2De *	operator[] (int i) const
Stack
Stack related functionality
void	push (List2De *pIt)
	prepend an item (insert as first item) More...
void	pushBack (List2De *pIt)
	append an item (insert after last) More...
List2De *	pop (void)
	extract first item
List2De *	popBack (void)
	extract last item

Protected Attributes
List2De *	it_1
	pointer to first element in list
int	iCnt
	number of items that belong to this chain

Friends
class	List2De

Detailed Description

class representing the list header in a linked list system

Overview

These lists are simple chains of objects. Each list must have:

• a header (List2Dh) that holds a pointer to the first item
• a number of 0 or more items that inherit from List2De (holding only a forward and a backward pointer).

Creation and destruction. Extracting from chain.

The constructor for this class only initialises itself. No chain can be appended at the moment of creation. Destruction code makes use of the erase() function to destroy all child elements (it assumes that the elements were allocated using new() and deletes them using delete).

The erase() function is public and may be used at any time to clean the list and delete all items in it (freeing of memory included). Also, low level access to internal fields is allowed using setFirst() and setCount();

Retrieveing an item

To get an item at a particular 0 based index use item(). First and last items in the chain may be found using first() and last().

Informative functions

To get the number of items that are hosted inside a chain use the count() function. To find out if the chain contains a particular pointer, feed it to the has() function, that returns true if the item was found. A similar function is itemIndex(), that returns the 0 based index of a pointer or -1 if it was not found.

Adding items

Items may be append() -ed, prepend() -ed to the chain or insert() -ed at a given, 0 based, index. It should be noted that none of these functions check if the item is already part of a chain. If the item is part of another chain, the caller is required to extract the item before the call.

If the caller already inserted the items into the chain, ackAdd() function may be used to inform the header AFTER the insertion. The function will only update the counter and, if inserted item is first item, the pointer.

Removing items

To extract an item from the chain WITHOUT deleting the item, remove() function is used. The caller may provide either the 0 based index or the pointer to the item to remove.

If the caller already removed the items from the chain, ackDel() function may be used to inform the header AFTER the removal. The function will only update the counter and, if the item is first item, the pointer. It is expected that the item has it's internal fields intact (pointer to next item is used to replace internal pointer).

Member Function Documentation

void List2Dh::ackAdd ( List2De *  pNew )

inline

header is informed about an item being added

If the caller already inserted the items into the chain, this function may be used to inform the header AFTER the insertion. The function will only update the counter and, if inserted item is first item, the pointer.

void List2Dh::ackDel ( List2De *  pNew )

inline

header is informed about an item being deleted

If the caller already removed the items from the chain, ackDel() function may be used to inform the header AFTER the removal. The function will only update the counter and, if the item is first item, the pointer. It is expected that the item has it's internal fields intact (pointer to next item is used to replace internal pointer).

void List2Dh::append

(

List2De *

pIt

)

append an item (insert after last)

It should be noted that this function does not check if the item is already part of a chain. If the item is part of another chain, the caller is required to extract the item before the call.

List2De* List2Dh::at ( int  i ) const

inline

get nth item

void List2Dh::erase

(

void

)

remove all items from this list by deleting them

This function assumes that the List2De elements were allocated using new() and it deletes them using delete).

void List2Dh::insert	(	List2De *	p_new,
		int	index
	)

insert a item at specified index

It should be noted that this function does not check if the item is already part of a chain. If the item is part of another chain, the caller is required to extract the item before the call.

List2De * List2Dh::item

(

int

i

)

const

get nth item

int List2Dh::itemIndex

(

const List2De *

pIt

)

const

returns the index of a particular item inside this chain

The index is 0 based. If the pointer was not found inside the chain the function returns -1.

List2De* List2Dh::operator[] ( int  i ) const

inline

get nth item

void List2Dh::prepend

(

List2De *

pIt

)

prepend an item (insert as first item)

It should be noted that this function does not check if the item is already part of a chain. If the item is part of another chain, the caller is required to extract the item before the call.

void List2Dh::push ( List2De *  pIt )

inline

prepend an item (insert as first item)

It should be noted that this function does not check if the item is already part of a chain. If the item is part of another chain, the caller is required to extract the item before the call.

void List2Dh::pushBack ( List2De *  pIt )

inline

append an item (insert after last)

It should be noted that this function does not check if the item is already part of a chain. If the item is part of another chain, the caller is required to extract the item before the call.

void List2Dh::remove

(

int

i

)

remove the item at given index

extract an item from the chain WITHOUT deleting the item

void List2Dh::remove

(

List2De *

pIt

)

remove a particular item

extract an item from the chain WITHOUT deleting the item

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

• /media/data/my-dev/libbbb/src/lists/list2d.h
• /media/data/my-dev/libbbb/src/lists/list2d.cc