diff options
Diffstat (limited to 'doc/src/classes/q3valuelist.qdoc')
| -rw-r--r-- | doc/src/classes/q3valuelist.qdoc | 569 |
1 files changed, 569 insertions, 0 deletions
diff --git a/doc/src/classes/q3valuelist.qdoc b/doc/src/classes/q3valuelist.qdoc new file mode 100644 index 000000000..fd73763e2 --- /dev/null +++ b/doc/src/classes/q3valuelist.qdoc @@ -0,0 +1,569 @@ +/**************************************************************************** +** +** 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 either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** 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 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at http://www.qtsoftware.com/contact. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \class Q3ValueList + \brief The Q3ValueList class is a value-based template class that + provides lists. + \compat + + Q3ValueList is a Qt implementation of an STL-like list container. + It can be used in your application if the standard \c list is not + available for your target platforms. + + Q3ValueList\<T\> defines a template instance to create a list of + values that all have the class T. Note that Q3ValueList does not + store pointers to the members of the list; it holds a copy of + every member. This is why these kinds of classes are called "value + based"; Q3PtrList and Q3Dict are "pointer based". + + Q3ValueList contains and manages a collection of objects of type T + and provides iterators that allow the contained objects to be + addressed. Q3ValueList owns the contained items. For more relaxed + ownership semantics, see Q3PtrCollection and friends which are + pointer-based containers. + + Some classes cannot be used within a Q3ValueList, for example, all + classes derived from QObject and thus all classes that implement + widgets. Only values can be used in a Q3ValueList. To qualify as a + value the class must provide: + \list + \i a copy constructor; + \i an assignment operator; + \i a default constructor, i.e. a constructor that does not take any arguments. + \endlist + + Note that C++ defaults to field-by-field assignment operators and + copy constructors if no explicit version is supplied. In many + cases this is sufficient. + + In addition, some compilers (e.g. Sun CC) might require that the + class provides an equality operator (operator==()). + + Q3ValueList's function naming is consistent with the other Qt + classes (e.g. count(), isEmpty()). Q3ValueList also provides extra + functions for compatibility with STL algorithms, such as size() + and empty(). Programmers already familiar with the STL \c list may + prefer to use the STL-compatible functions. + + Example: + \snippet doc/src/snippets/code/doc_src_q3valuelist.qdoc 0 + + + Notice that the latest changes to Mary's salary did not affect the + value in the list because the list created a copy of Mary's entry. + + There are several ways to find items in the list. The begin() and + end() functions return iterators to the beginning and end of the + list. The advantage of getting an iterator is that you can move + forward or backward from this position by + incrementing/decrementing the iterator. The iterator returned by + end() points to the item which is one \e past the last item in the + container. The past-the-end iterator is still associated with the + list it belongs to, however it is \e not dereferenceable; + operator*() will not return a well-defined value. If the list is + empty(), the iterator returned by begin() will equal the iterator + returned by end(). + + It is safe to have multiple iterators a the list at the same + time. If some member of the list is removed, only iterators + pointing to the removed member become invalid. Inserting into the + list does not invalidate any iterator. For convenience, the + function last() returns a reference to the last item in the list, + and first() returns a reference to the first item. If the + list is empty(), both last() and first() have undefined behavior + (your application will crash or do unpredictable things). Use + last() and first() with caution, for example: + + \snippet doc/src/snippets/code/doc_src_q3valuelist.qdoc 1 + + Because Q3ValueList is value-based there is no need to be careful + about deleting items in the list. The list holds its own copies + and will free them if the corresponding member or the list itself + is deleted. You can force the list to free all of its items with + clear(). + + Q3ValueList is shared implicitly, which means it can be copied in + constant time, i.e. O(1). If multiple Q3ValueList instances share + the same data and one needs to modify its contents, this modifying + instance makes a copy and modifies its private copy; therefore it + does not affect the other instances; this takes O(n) time. This is + often called "copy on write". If a Q3ValueList is being used in a + multi-threaded program, you must protect all access to the list. + See \l QMutex. + + There are several ways to insert items into the list. The + prepend() and append() functions insert items at the beginning and + the end of the list respectively. The insert() function comes in + several flavors and can be used to add one or more items at + specific positions within the list. + + Items can also be removed from the list in several ways. There + are several variants of the remove() function, which removes a + specific item from the list. The remove() function will find and + remove items according to a specific item value. + + \sa Q3ValueListIterator +*/ + +/*! \typedef Q3ValueList::iterator + The list's iterator type, Q3ValueListIterator. */ +/*! \typedef Q3ValueList::const_iterator + The list's const iterator type, Q3ValueListConstIterator. */ +/*! \typedef Q3ValueList::value_type + The type of the object stored in the list, T. */ +/*! \typedef Q3ValueList::pointer + The pointer to T type. */ +/*! \typedef Q3ValueList::const_pointer + The const pointer to T type. */ +/*! \typedef Q3ValueList::reference + The reference to T type. */ +/*! \typedef Q3ValueList::const_reference + The const reference to T type. */ +/*! \typedef Q3ValueList::size_type + An unsigned integral type, used to represent various sizes. */ +/*! \typedef Q3ValueList::difference_type + \internal +*/ +/*! + \fn Q3ValueList::Q3ValueList() + + Constructs an empty list. +*/ + +/*! + \fn Q3ValueList::Q3ValueList( const Q3ValueList<T>& l ) + \fn Q3ValueList::Q3ValueList( const QList<T>& l ) + \fn Q3ValueList::Q3ValueList( const QLinkedList<T>& l ) + + Constructs a copy of \a l. +*/ + +/*! + \fn Q3ValueList::Q3ValueList( const std::list<T>& l ) + + Contructs a copy of \a l. + + This constructor is provided for compatibility with STL + containers. +*/ + +/*! + \fn Q3ValueList::~Q3ValueList() + + Destroys the list. References to the values in the list and all + iterators of this list become invalidated. Note that it is + impossible for an iterator to check whether or not it is valid: + Q3ValueList is highly tuned for performance, not for error + checking. +*/ + +/*! + \fn bool Q3ValueList::operator== ( const Q3ValueList<T>& l ) const + + Compares both lists. + + Returns TRUE if this list and \a l are equal; otherwise returns + FALSE. +*/ + +/*! + \fn bool Q3ValueList::operator== ( const std::list<T>& l ) const + + \overload + + Returns TRUE if this list and \a l are equal; otherwise returns + FALSE. + + This operator is provided for compatibility with STL containers. +*/ + +/*! + \fn Q3ValueList<T>& Q3ValueList::operator= ( const Q3ValueList<T>& l ) + + Assigns \a l to this list and returns a reference to this list. + + All iterators of the current list become invalidated by this + operation. The cost of such an assignment is O(1) since Q3ValueList + is implicitly shared. +*/ + +/*! + \fn Q3ValueList<T>& Q3ValueList::operator= ( const QList<T>& l ) + + Assigns \a l to this list and returns a reference to this list. + + All iterators of the current list become invalidated by this + operation. +*/ + +/*! + \fn Q3ValueList<T>& Q3ValueList::operator= ( const std::list<T>& l ) + + \overload + + Assigns the contents of \a l to the list. + + All iterators of the current list become invalidated by this + operation. +*/ + +/*! + \fn bool Q3ValueList::operator!= ( const Q3ValueList<T>& l ) const + + Compares both lists. + + Returns TRUE if this list and \a l are unequal; otherwise returns + FALSE. +*/ + +/*! + \fn iterator Q3ValueList::insert( typename Q3ValueList<T>::Iterator it, const T& x ) + + Inserts the value \a x in front of the item pointed to by the + iterator, \a it. + + Returns an iterator pointing at the inserted item. + + \sa append(), prepend() +*/ + +/*! + \fn uint Q3ValueList::remove( const T& x ) + + \overload + + Removes all items that have value \a x and returns the number of + removed items. +*/ + +/*! + \fn QDataStream& operator>>( QDataStream& s, Q3ValueList<T>& l ) + + \relates Q3ValueList + + Reads a list, \a l, from the stream \a s. The type T stored in the + list must implement the streaming operator. +*/ + +/*! + \fn QDataStream& operator<<( QDataStream& s, const Q3ValueList<T>& l ) + + \overload + \relates Q3ValueList + + Writes a list, \a l, to the stream \a s. The type T stored in the + list must implement the streaming operator. +*/ + +/*! + \fn void Q3ValueList::insert( typename Q3ValueList<T>::Iterator pos, + typename Q3ValueList<T>::size_type n, const T& x ) + + \overload + + Inserts \a n copies of \a x before position \a pos. +*/ + +/*! + \fn Q3ValueList<T>& Q3ValueList::operator<< ( const T& x ) + + Adds the value \a x to the end of the list. + + Returns a reference to the list. +*/ + +/*! + \fn const T& Q3ValueList::operator[] ( typename Q3ValueList<T>::size_type i ) const + + Returns a const reference to the item with index \a i in the list. + It is up to you to check whether this item really exists. You can + do that easily with the count() function. However this operator + does not check whether \a i is in range and will deliver undefined + results if it does not exist. + + \warning This function uses a linear search and can be extremely + slow for large lists. Q3ValueList is not optimized for random item + access. If you need random access use a different container, such + as Q3ValueVector. +*/ + +/*! + \fn T& Q3ValueList::operator[] ( typename Q3ValueList<T>::size_type i ) + + \overload + + Returns a non-const reference to the item with index \a i. +*/ + +/*! + \fn const_iterator Q3ValueList::at( typename Q3ValueList<T>::size_type i ) const + + Returns an iterator pointing to the item at position \a i in the + list, or an undefined value if the index is out of range. + + \warning This function uses a linear search and can be extremely + slow for large lists. Q3ValueList is not optimized for random item + access. If you need random access use a different container, such + as Q3ValueVector. +*/ + +/*! + \fn iterator Q3ValueList::at( typename Q3ValueList<T>::size_type i ) + + \overload + + Returns an iterator pointing to the item at position \a i in the + list, or an undefined value if the index is out of range. + +*/ + +/*! + \fn iterator Q3ValueList::fromLast() + + \overload + + Returns an iterator to the last item in the list, or end() if + there is no last item. + + Use the end() function instead. For example: + + \snippet doc/src/snippets/code/doc_src_q3valuelist.qdoc 2 + +*/ + +/*! + \fn const_iterator Q3ValueList::fromLast() const + + Returns an iterator to the last item in the list, or end() if + there is no last item. + + Use the end() function instead. For example: + + \snippet doc/src/snippets/code/doc_src_q3valuelist.qdoc 3 + +*/ + +/*! + \fn Q3ValueList<T> Q3ValueList::operator+( const Q3ValueList<T>& l ) const + + Creates a new list and fills it with the items of this list. Then + the items of \a l are appended. Returns the new list. +*/ + +/*! + \fn Q3ValueList<T>& Q3ValueList::operator+= ( const Q3ValueList<T>& l ) + + Appends the items of \a l to this list. Returns a reference to + this list. +*/ + +/*! + \fn Q3ValueList<T>& Q3ValueList::operator+= ( const T& x ) + + \overload + + Appends the value \a x to the list. Returns a reference to the + list. +*/ + +/*! + \fn iterator Q3ValueList::append( const T& x ) + + Inserts \a x at the end of the list. + + \sa insert(), prepend() +*/ + +/*! + \fn iterator Q3ValueList::prepend( const T& x ) + + Inserts \a x at the beginning of the list. + + \sa insert(), append() +*/ + +/*! + \fn iterator Q3ValueList::remove( typename Q3ValueList<T>::Iterator it ) + + Removes the item pointed to by \a it from the list. No iterators + other than \a it or other iterators pointing at the same item as + \a it are invalidated. Returns an iterator to the next item after + \a it, or end() if there is no such item. + + \sa clear() +*/ + +/*! + \fn uint Q3ValueList::contains( const T& x ) const + + Returns the number of occurrences of the value \a x in the list. +*/ + +/*! + \class Q3ValueListIterator + \brief The Q3ValueListIterator class provides an iterator for Q3ValueList. + \compat + + An iterator is a class for accessing the items of a container + class: a generalization of the index in an array. A pointer + into a "const char *" and an index into an "int[]" are both + iterators, and the general idea is to provide that functionality + for any data structure. + + The Q3ValueListIterator class is an iterator for Q3ValueList + instantiations. You can create the appropriate iterator type by + using the \c iterator typedef provided by Q3ValueList. + + The only way to access the items in a Q3ValueList is to use an + iterator. + + Example (see Q3ValueList for the complete code): + \snippet doc/src/snippets/code/doc_src_q3valuelist.qdoc 4 + + Q3ValueList is highly optimized for performance and memory usage. + This means that you must be careful: Q3ValueList does not know + about all its iterators and the iterators don't know to which list + they belong. This makes things very fast, but if you're not + careful, you can get spectacular bugs. Always make sure iterators + are valid before dereferencing them or using them as parameters to + generic algorithms in the STL. + + Using an invalid iterator is undefined (your application will + probably crash). Many Qt functions return const value lists; to + iterate over these you should make a copy and iterate over the + copy. + + For every Iterator there is a ConstIterator. When accessing a + Q3ValueList in a const environment or if the reference or pointer + to the list is itself const, then you must use the ConstIterator. + Its semantics are the same as the Iterator, but it only returns + const references. + + \sa Q3ValueList, Q3ValueListConstIterator +*/ + +/*! + \fn Q3ValueListIterator::Q3ValueListIterator() + + Constructs an unitialized iterator. +*/ + +/*! + \fn Q3ValueListIterator::Q3ValueListIterator(const Q3ValueListIterator &o) + \fn Q3ValueListIterator::Q3ValueListIterator(const typename QLinkedList<T>::iterator &o) + + Constucts a copy of iterator \a o. +*/ + +/*! + \class Q3ValueListConstIterator + \brief The Q3ValueListConstIterator class provides a const iterator + for Q3ValueList. + \compat + + In contrast to Q3ValueListIterator, this class is used to iterate + over a const list. It does not allow modification of the values of + the list since that would break const semantics. + + You can create the appropriate const iterator type by using the \c + const_iterator typedef provided by Q3ValueList. + + For more information on Q3ValueList iterators, see + Q3ValueListIterator. + + \sa Q3ValueListIterator, Q3ValueList +*/ + +/*! + \fn Q3ValueListConstIterator::Q3ValueListConstIterator() + + Constructs an unitialized iterator. +*/ + +/*! + \fn Q3ValueListConstIterator::Q3ValueListConstIterator(const Q3ValueListConstIterator &o) + \fn Q3ValueListConstIterator::Q3ValueListConstIterator(const typename QLinkedList<T>::const_iterator &o) + \fn Q3ValueListConstIterator::Q3ValueListConstIterator(const typename QLinkedList<T>::iterator &o) + + Constructs a copy of iterator \a o. +*/ + +/*! + \typedef Q3ValueList::Iterator + + This iterator is an instantiation of Q3ValueListIterator for the + same type as this Q3ValueList. In other words, if you instantiate + Q3ValueList<int>, Iterator is a Q3ValueListIterator<int>. Several + member function use it, such as Q3ValueList::begin(), which returns + an iterator pointing to the first item in the list. + + Functionally, this is almost the same as ConstIterator. The only + difference is that you cannot use ConstIterator for non-const + operations, and that the compiler can often generate better code + if you use ConstIterator. + + \sa Q3ValueListIterator ConstIterator +*/ + +/*! + \typedef Q3ValueList::ConstIterator + + This iterator is an instantiation of Q3ValueListConstIterator for + the same type as this Q3ValueList. In other words, if you + instantiate Q3ValueList<int>, ConstIterator is a + Q3ValueListConstIterator<int>. Several member function use it, such + as Q3ValueList::begin(), which returns an iterator pointing to the + first item in the list. + + Functionally, this is almost the same as Iterator. The only + difference is you cannot use ConstIterator for non-const + operations, and that the compiler can often generate better code + if you use ConstIterator. + + \sa Q3ValueListIterator Iterator +*/ + +/*! + \fn Q3ValueList::operator QList<T>() const + + Automatically converts a Q3ValueList<T> into a QList<T>. +*/ |