path: root/doc/src/q3ptrvector.qdoc

/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain
** additional rights.  These rights are described in the Nokia Qt LGPL
** Exception version 1.1, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

/*!
  \class Q3PtrVector
  \brief The Q3PtrVector class is a template collection class that
  provides a vector (array).
  \compat

  Q3ValueVector is an STL-compatible alternative to this class.

  Q3PtrVector is implemented as a template class. Defines a template
  instance Q3PtrVector\<X\> to create a vector that contains pointers
  to X (X*).

  A vector is the same as an array. The main difference between
  Q3PtrVector and Q3MemArray is that Q3PtrVector stores pointers to the
  elements, whereas Q3MemArray stores the elements themselves (i.e.
  Q3MemArray is value-based and Q3PtrVector is pointer-based).

  Items are added to the vector using insert() or fill(). Items are
  removed with remove(). You can get a pointer to an item at a
  particular index position using at().

  Unless otherwise stated, all functions that remove items from the
  vector will also delete the element pointed to if \link
  setAutoDelete() auto-deletion\endlink is enabled. By default,
  auto-deletion is disabled; see setAutoDelete(). This behavior can
  be changed in a subclass by reimplementing the virtual function
  deleteItem().

  Functions that compare items (find() and sort() for example) will
  do so using the virtual function compareItems(). The default
  implementation of this function only compares the pointer values.
  Reimplement compareItems() in a subclass to get searching and
  sorting based on the item contents. You can perform a linear
  search for a pointer in the vector using findRef(), or a binary
  search (of a sorted vector) using bsearch(). You can count the
  number of times an item appears in the vector with contains() or
  containsRef().

  \sa Q3MemArray
*/

/*!
  \fn Q3PtrVector::Q3PtrVector()

  Constructs a null vector.

  \sa isNull()
*/

/*!
  \fn Q3PtrVector::Q3PtrVector(uint size)

  Constructs an vector with room for \a size items. Makes a null
  vector if \a size == 0.

  All \a size positions in the vector are initialized to 0.

  \sa size(), resize(), isNull()
*/

/*!
  \fn Q3PtrVector::Q3PtrVector(const Q3PtrVector<type> &v)

  Constructs a copy of \a v. Only the pointers are copied (i.e.
  shallow copy).
*/

/*!
  \fn Q3PtrVector::~Q3PtrVector()

  Removes all items from the vector, and destroys the vector itself.

  \sa clear()
*/

/*!
  \fn Q3PtrVector<type> &Q3PtrVector::operator=(const Q3PtrVector<type> &v)

  Assigns \a v to this vector and returns a reference to this
  vector.

  This vector is first cleared and then all the items from \a v are
  copied into the vector. Only the pointers are copied (i.e. shallow
  copy).

  \sa clear()
*/

/*!
  \fn type **Q3PtrVector::data() const

  Returns a pointer to the actual vector data, which is an array of
  type*.

  The vector is a null vector if data() == 0 (null pointer).

  \sa isNull()
*/

/*!
  \fn uint Q3PtrVector::size() const

  Returns the size of the vector, i.e. the number of vector
  positions. This is also the maximum number of items the vector can
  hold.

  The vector is a null vector if size() == 0.

  \sa isNull(), resize(), count()
*/

/*!
  \fn uint Q3PtrVector::count() const 

  Returns the number of items in the vector. The vector is empty if
  count() == 0.

  \sa isEmpty(), size(), isNull()
*/

/*!
  \fn bool Q3PtrVector::isEmpty() const

  Returns true if the vector is empty; otherwise returns false.

  \sa count()
*/

/*!
  \fn bool Q3PtrVector::isNull() const

  Returns true if the vector is null; otherwise returns false.

  A null vector has size() == 0 and data() == 0.

  \sa size()
*/

/*!
  \fn bool Q3PtrVector::resize(uint size)

  Resizes (expands or shrinks) the vector to \a size elements. The
  vector becomes a null vector if \a size == 0.

  Any items at position \a size or beyond in the vector are removed.
  New positions are initialized to 0.

  Returns true if successful, i.e. if the memory was successfully
  allocated; otherwise returns false.

  \sa size(), isNull()
*/

/*!
  \fn bool Q3PtrVector::insert(uint i, const type *d)

  Sets position \a i in the vector to contain the item \a d. \a i
  must be less than size(). Any previous element in position \a i is
  removed.

  Returns true if \a i is within range; otherwise returns false.

  \sa at()
*/

/*!
  \fn bool Q3PtrVector::remove(uint i)

  Removes the item at position \a i in the vector, if there is one.
  \a i must be less than size().

  Returns true if \a i is within range; otherwise returns false.

  \sa take(), at()
*/

/*!
  \fn type* Q3PtrVector::take(uint i)

  Returns the item at position \a i in the vector, and removes that
  item from the vector. \a i must be less than size(). If there is
  no item at position \a i, 0 is returned.

  Unlike remove(), this function does \e not call deleteItem() for
  the removed item.

  \sa remove(), at()
*/

/*!
  \fn void Q3PtrVector::clear()

  Removes all items from the vector, and destroys the vector itself.

  The vector becomes a null vector.

  \sa isNull()
*/

/*!
  \fn bool Q3PtrVector::fill(const type *d, int size)

  Inserts item \a d in all positions in the vector. Any existing
  items are removed. If \a d is 0, the vector becomes empty.

  If \a size >= 0, the vector is first resized to \a size. By
  default, \a size is -1.

  Returns true if successful, i.e. \a size is the same as the
  current size, or \a size is larger and the memory has successfully
  been allocated; otherwise returns false.

  \sa resize(), insert(), isEmpty()
*/

/*!
  \fn void Q3PtrVector::sort()

  Sorts the items in ascending order. Any empty positions will be
  put last.

  Compares items using the virtual function compareItems().

  \sa bsearch()
*/

/*!
  \fn int Q3PtrVector::bsearch(const type* d) const

  In a sorted array, finds the first occurrence of \a d using a
  binary search. For a sorted array, this is generally much faster
  than find(), which performs a linear search.

  Returns the position of \a d, or -1 if \a d could not be found. \a
  d must not be 0.

  Compares items using the virtual function compareItems().

  \sa sort(), find()
*/


/*!
  \fn int Q3PtrVector::findRef(const type *d, uint i) const

  Finds the first occurrence of the item pointer \a d in the vector
  using a linear search. The search starts at position \a i, which
  must be less than size(). \a i is by default 0; i.e. the search
  starts at the start of the vector.

  Returns the position of \a d, or -1 if \a d could not be found.

  This function does \e not use compareItems() to compare items.

  Use the much faster bsearch() to search a sorted vector.

  \sa find(), bsearch()
*/

/*!
  \fn int Q3PtrVector::find(const type *d, uint i) const

  Finds the first occurrence of item \a d in the vector using a
  linear search. The search starts at position \a i, which must be
  less than size(). \a i is by default 0; i.e. the search starts at
  the start of the vector.

  Returns the position of \a d, or -1 if \a d could not be found.

  Compares items using the virtual function compareItems().

  Use the much faster bsearch() to search a sorted vector.

  \sa findRef(), bsearch()
*/


/*!
  \fn uint Q3PtrVector::containsRef(const type *d) const

  Returns the number of occurrences of the item pointer \a d in the
  vector.

  This function does \e not use compareItems() to compare items.

  \sa findRef()
*/

/*!
  \fn uint Q3PtrVector::contains(const type *d) const

  Returns the number of occurrences of item \a d in the vector.

  Compares items using the virtual function compareItems().

  \sa containsRef()
*/

/*!
  \fn type *Q3PtrVector::operator[](int i) const

  Returns the item at position \a i, or 0 if there is no item at
  that position. \a i must be less than size().

  Equivalent to at(\a i).

  \sa at()
*/

/*!
  \fn type *Q3PtrVector::at(uint i) const

  Returns the item at position \a i, or 0 if there is no item at
  that position. \a i must be less than size().
*/


/*!
  \fn void Q3PtrVector::toList(Q3GList *list) const

  \internal

  Copies all items in this vector to the list \a list. \a list is
  first cleared and then all items are appended to \a list.

  \sa Q3PtrList, Q3PtrStack, Q3PtrQueue
*/

/*!
  \fn int Q3PtrVector::compareItems(Q3PtrCollection::Item d1,
				    Q3PtrCollection::Item d2)

  This virtual function compares two list items.

  Returns:
  \list
  \i zero if \a d1 == \a d2
  \i nonzero if \a d1 != \a d2
  \endlist

  This function returns \e int rather than \e bool so that
  reimplementations can return one of three values and use it to
  sort by:
  \list
  \i 0 if \a d1 == \a d2
  \i \> 0 (positive integer) if \a d1 \> \a d2
  \i \< 0 (negative integer) if \a d1 \< \a d2
  \endlist

  The sort() and bsearch() functions require compareItems() to be
  implemented as described here.

  This function should not modify the vector because some const
  functions call compareItems().
*/

/*!
  \fn QDataStream& Q3PtrVector::read(QDataStream &s,
				     Q3PtrCollection::Item &item)

  Reads a vector item, \a item, from the stream \a s and returns a
  reference to the stream.

  The default implementation sets \a item to 0.

  \sa write()
*/

/*!
  \fn QDataStream& Q3PtrVector::write(QDataStream &s,
			 	      Q3PtrCollection::Item item) const

  Writes a vector item, \a item, to the stream \a s and returns a
  reference to the stream.

  The default implementation does nothing.

  \sa read()
*/
  
/*!
  \fn bool Q3PtrVector::operator==(const Q3PtrVector<type> &v) const

  Returns true if this vector and \a v are equal; otherwise returns
  false.
*/