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<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QPtrList Class Reference</h1>
<p>The QPtrList class is a template class that provides
doubly-linked lists.
<a href="#details">More...</a>
<p><tt>#include <<a href="qptrlist-h.html">qptrlist.h</a>></tt>
<p>Inherits <a href="qptrcollection.html">QPtrCollection</a>.
<p>Inherited by <a href="qsortedlist.html">QSortedList</a> and <a href="qstrlist.html">QStrList</a>.
<p><a href="qptrlist-members.html">List of all member functions.</a>
<h2>Public Members</h2>
<ul>
<li><div class=fn><a href="#QPtrList"><b>QPtrList</b></a> ()</div></li>
<li><div class=fn><a href="#QPtrList-2"><b>QPtrList</b></a> ( const QPtrList<type> & list )</div></li>
<li><div class=fn><a href="#~QPtrList"><b>~QPtrList</b></a> ()</div></li>
<li><div class=fn>QPtrList<type> & <a href="#operator-eq"><b>operator=</b></a> ( const QPtrList<type> & list )</div></li>
<li><div class=fn>bool <a href="#operator-eq-eq"><b>operator==</b></a> ( const QPtrList<type> & list ) const</div></li>
<li><div class=fn>virtual uint <a href="#count"><b>count</b></a> () const</div></li>
<li><div class=fn>bool <a href="#isEmpty"><b>isEmpty</b></a> () const</div></li>
<li><div class=fn>bool <a href="#insert"><b>insert</b></a> ( uint index, const type * item )</div></li>
<li><div class=fn>void <a href="#inSort"><b>inSort</b></a> ( const type * item )</div></li>
<li><div class=fn>void <a href="#prepend"><b>prepend</b></a> ( const type * item )</div></li>
<li><div class=fn>void <a href="#append"><b>append</b></a> ( const type * item )</div></li>
<li><div class=fn>bool <a href="#remove"><b>remove</b></a> ( uint index )</div></li>
<li><div class=fn>bool <a href="#remove-2"><b>remove</b></a> ()</div></li>
<li><div class=fn>bool <a href="#remove-3"><b>remove</b></a> ( const type * item )</div></li>
<li><div class=fn>bool <a href="#removeRef"><b>removeRef</b></a> ( const type * item )</div></li>
<li><div class=fn>void <a href="#removeNode"><b>removeNode</b></a> ( QLNode * node )</div></li>
<li><div class=fn>bool <a href="#removeFirst"><b>removeFirst</b></a> ()</div></li>
<li><div class=fn>bool <a href="#removeLast"><b>removeLast</b></a> ()</div></li>
<li><div class=fn>type * <a href="#take"><b>take</b></a> ( uint index )</div></li>
<li><div class=fn>type * <a href="#take-2"><b>take</b></a> ()</div></li>
<li><div class=fn>type * <a href="#takeNode"><b>takeNode</b></a> ( QLNode * node )</div></li>
<li><div class=fn>virtual void <a href="#clear"><b>clear</b></a> ()</div></li>
<li><div class=fn>void <a href="#sort"><b>sort</b></a> ()</div></li>
<li><div class=fn>int <a href="#find"><b>find</b></a> ( const type * item )</div></li>
<li><div class=fn>int <a href="#findNext"><b>findNext</b></a> ( const type * item )</div></li>
<li><div class=fn>int <a href="#findRef"><b>findRef</b></a> ( const type * item )</div></li>
<li><div class=fn>int <a href="#findNextRef"><b>findNextRef</b></a> ( const type * item )</div></li>
<li><div class=fn>uint <a href="#contains"><b>contains</b></a> ( const type * item ) const</div></li>
<li><div class=fn>uint <a href="#containsRef"><b>containsRef</b></a> ( const type * item ) const</div></li>
<li><div class=fn>type * <a href="#at"><b>at</b></a> ( uint index )</div></li>
<li><div class=fn>int <a href="#at-2"><b>at</b></a> () const</div></li>
<li><div class=fn>type * <a href="#current"><b>current</b></a> () const</div></li>
<li><div class=fn>QLNode * <a href="#currentNode"><b>currentNode</b></a> () const</div></li>
<li><div class=fn>type * <a href="#getFirst"><b>getFirst</b></a> () const</div></li>
<li><div class=fn>type * <a href="#getLast"><b>getLast</b></a> () const</div></li>
<li><div class=fn>type * <a href="#first"><b>first</b></a> ()</div></li>
<li><div class=fn>type * <a href="#last"><b>last</b></a> ()</div></li>
<li><div class=fn>type * <a href="#next"><b>next</b></a> ()</div></li>
<li><div class=fn>type * <a href="#prev"><b>prev</b></a> ()</div></li>
<li><div class=fn>void <a href="#toVector"><b>toVector</b></a> ( QGVector * vec ) const</div></li>
</ul>
<h2>Important Inherited Members</h2>
<ul>
<li><div class=fn>bool <a href="#autoDelete"><b>autoDelete</b></a> () const</div></li>
<li><div class=fn>void <a href="#setAutoDelete"><b>setAutoDelete</b></a> ( bool enable )</div></li>
</ul>
<h2>Protected Members</h2>
<ul>
<li><div class=fn>virtual int <a href="#compareItems"><b>compareItems</b></a> ( QPtrCollection::Item item1, QPtrCollection::Item item2 )</div></li>
<li><div class=fn>virtual QDataStream & <a href="#read"><b>read</b></a> ( QDataStream & s, QPtrCollection::Item & item )</div></li>
<li><div class=fn>virtual QDataStream & <a href="#write"><b>write</b></a> ( QDataStream & s, QPtrCollection::Item item ) const</div></li>
</ul>
<hr><a name="details"></a><h2>Detailed Description</h2>
The QPtrList class is a template class that provides
doubly-linked lists.
<p>
<p>
<p> <a href="qvaluelist.html">QValueList</a> is an STL-compatible alternative to this class.
<p> Define a template instance QPtrList<X> to create a list that
operates on pointers to X (X*).
<p> The list class is indexable and has a <a href="#at">current index</a>
and a <a href="#current">current item</a>. The first item corresponds
to index 0. The current index is -1 if the current item is null.
<p> Items are inserted with <a href="#prepend">prepend</a>(), <a href="#insert">insert</a>() or <a href="#append">append</a>(). Items are
removed with <a href="#remove">remove</a>(), <a href="#removeRef">removeRef</a>(), <a href="#removeFirst">removeFirst</a>() and
<a href="#removeLast">removeLast</a>(). You can search for an item using <a href="#find">find</a>(), <a href="#findNext">findNext</a>(),
<a href="#findRef">findRef</a>() or <a href="#findNextRef">findNextRef</a>(). The list can be sorted with <a href="#sort">sort</a>().
You can count the number of occurrences of an item with <a href="#contains">contains</a>()
or <a href="#containsRef">containsRef</a>(). You can get a pointer to the current item with
<a href="#current">current</a>(), to an item at a particular index position in the list
with <a href="#at">at</a>() or to the first or last item with <a href="#getFirst">getFirst</a>() and
<a href="#getLast">getLast</a>(). You can also iterate over the list with <a href="#first">first</a>(),
<a href="#last">last</a>(), <a href="#next">next</a>() and <a href="#prev">prev</a>() (which all update current()). The
list's deletion property is set with <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>().
<p> <a name="example"></a>
<p> Example:
<pre>
class Employee
{
public:
Employee() : sn( 0 ) { }
Employee( const <a href="qstring.html">QString</a>& forename, const <a href="qstring.html">QString</a>& surname, int salary )
: fn( forename ), sn( surname ), sal( salary )
{ }
void setSalary( int salary ) { sal = salary; }
<a href="qstring.html">QString</a> forename() const { return fn; }
<a href="qstring.html">QString</a> surname() const { return sn; }
int salary() const { return sal; }
private:
<a href="qstring.html">QString</a> fn;
<a href="qstring.html">QString</a> sn;
int sal;
};
QPtrList<Employee> list;
list.<a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>( TRUE ); // the list owns the objects
list.<a href="#append">append</a>( new Employee("John", "Doe", 50000) );
list.<a href="#append">append</a>( new Employee("Jane", "Williams", 80000) );
list.<a href="#append">append</a>( new Employee("Tom", "Jones", 60000) );
Employee *employee;
for ( employee = list.<a href="#first">first</a>(); employee; employee = list.<a href="#next">next</a>() )
cout << employee->surname().latin1() << ", " <<
employee->forename().latin1() << " earns " <<
employee->salary() << endl;
cout << endl;
// very inefficient for big lists
for ( uint i = 0; i < list.<a href="#count">count</a>(); ++i )
if ( list.<a href="#at">at</a>(i) )
cout << list.<a href="#at">at</a>( i )->surname().latin1() << endl;
</pre>
<p> The output is
<pre>
Doe, John earns 50000
Williams, Jane earns 80000
Jones, Tom earns 60000
Doe
Williams
Jones
</pre>
<p> QPtrList has several member functions for traversing the list, but
using a <a href="qptrlistiterator.html">QPtrListIterator</a> can be more practical. Multiple list
iterators may traverse the same list, independently of each other
and of the current list item.
<p> In the example above we make the call <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>(TRUE).
Enabling auto-deletion tells the list to delete items that are removed
from the list. The default is to not delete items when they are
removed but that would cause a memory leak in our example because we have
no other references to the list items.
<p> List items are stored as <tt>void*</tt> in an internal QLNode, which also
holds pointers to the next and previous list items. The functions
<a href="#currentNode">currentNode</a>(), <a href="#removeNode">removeNode</a>(), and <a href="#takeNode">takeNode</a>() operate directly on the
QLNode, but they should be used with care. The data component of the
node is available through QLNode::getData().
<p> When inserting an item into a list only the pointer is copied, not
the item itself, i.e. we make a <a href="shclass.html#shallow-copy">shallow copy</a>. It is possible to make
the list copy all of the item's data (deep copy) when an item is
inserted. <a href="#insert">insert</a>(), <a href="#inSort">inSort</a>() and <a href="#append">append</a>() call the virtual function
<a href="qptrcollection.html#newItem">QPtrCollection::newItem</a>() for the item to be inserted. Inherit a
list and reimplement it if you want deep copies.
<p> When removing an item from a list, the virtual function
<a href="qptrcollection.html#deleteItem">QPtrCollection::deleteItem</a>() is called. QPtrList's default implementation
is to delete the item if auto-deletion is enabled.
<p> The virtual function <a href="#compareItems">compareItems</a>() can be reimplemented to
compare two list items. This function is called from all list functions
that need to compare list items, for instance <a href="#remove">remove</a>(const type*).
If you only want to deal with pointers, there are functions that
compare pointers instead, for instance <a href="#removeRef">removeRef</a>(const type*).
These functions are somewhat faster than those that call compareItems().
<p> The <a href="qstrlist.html">QStrList</a> class defined in <a href="qstrlist-h.html">qstrlist.h</a> is a list of <tt>char*</tt>. It
reimplements <a href="qptrcollection.html#newItem">newItem</a>(), <a href="qptrcollection.html#deleteItem">deleteItem</a>() and compareItems().
<p> <p>See also <a href="qptrlistiterator.html">QPtrListIterator</a>, <a href="collection.html">Collection Classes</a> and <a href="tools.html">Non-GUI Classes</a>.
<hr><h2>Member Function Documentation</h2>
<h3 class=fn><a name="QPtrList"></a>QPtrList::QPtrList ()
</h3>
Constructs an empty list.
<h3 class=fn><a name="QPtrList-2"></a>QPtrList::QPtrList ( const <a href="qptrlist.html">QPtrList</a><type> & list )
</h3>
Constructs a copy of <em>list</em>.
<p> Each item in <em>list</em> is <a href="#append">appended</a> to this list.
Only the pointers are copied (shallow copy).
<h3 class=fn><a name="~QPtrList"></a>QPtrList::~QPtrList ()
</h3>
Removes all items from the list and destroys the list.
<p> All list iterators that access this list will be reset.
<p> <p>See also <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>().
<h3 class=fn>void <a name="append"></a>QPtrList::append ( const type * item )
</h3>
Inserts the <em>item</em> at the end of the list.
<p> The inserted item becomes the current list item.
This is equivalent to <tt>insert( count(), item )</tt>.
<p> The <em>item</em> must not be a null pointer.
<p> <p>See also <a href="#insert">insert</a>(), <a href="#current">current</a>() and <a href="#prepend">prepend</a>().
<p>Examples: <a href="customlayout-example.html#x1810">customlayout/border.cpp</a>, <a href="customlayout-example.html#x1828">customlayout/card.cpp</a>, <a href="customlayout-example.html#x1787">customlayout/flow.cpp</a>, <a href="grapher-nsplugin-example.html#x2622">grapher/grapher.cpp</a>, <a href="listviews-example.html#x1229">listviews/listviews.cpp</a>, <a href="listviews-example.html#x1200">listviews/listviews.h</a> and <a href="qwerty-example.html#x649">qwerty/qwerty.cpp</a>.
<h3 class=fn>type * <a name="at"></a>QPtrList::at ( uint index )
</h3>
Returns a pointer to the item at position <em>index</em> in the list, or
null if the index is out of range.
<p> Sets the current list item to this item if <em>index</em> is valid.
The valid range is <tt>0..(count() - 1)</tt> inclusive.
<p> This function is very efficient. It starts scanning from the first
item, last item, or current item, whichever is closest to <em>index</em>.
<p> <p>See also <a href="#current">current</a>().
<p>Examples: <a href="customlayout-example.html#x1811">customlayout/border.cpp</a>, <a href="customlayout-example.html#x1829">customlayout/card.cpp</a>, <a href="customlayout-example.html#x1788">customlayout/flow.cpp</a>, <a href="dirview-example.html#x1690">dirview/dirview.cpp</a>, <a href="fileiconview-example.html#x1579">fileiconview/qfileiconview.cpp</a>, <a href="mdi-example.html#x1170">mdi/application.cpp</a> and <a href="qwerty-example.html#x650">qwerty/qwerty.cpp</a>.
<h3 class=fn>int <a name="at-2"></a>QPtrList::at () const
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Returns the index of the current list item. The returned value is -1
if the current item is null.
<p>See also <a href="#current">current</a>().
<h3 class=fn>bool <a name="autoDelete"></a>QPtrCollection::autoDelete () const
</h3>
<p> Returns the setting of the auto-delete option. The default is FALSE.
<p> <p>See also <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>().
<h3 class=fn>void <a name="clear"></a>QPtrList::clear ()<tt> [virtual]</tt>
</h3>
Removes all items from the list.
<p> The removed items are deleted if <a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled.
<p> All list iterators that access this list will be reset.
<p> <p>See also <a href="#remove">remove</a>(), <a href="#take">take</a>() and <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>().
<p>Reimplemented from <a href="qptrcollection.html#clear">QPtrCollection</a>.
<h3 class=fn>int <a name="compareItems"></a>QPtrList::compareItems ( <a href="qptrcollection.html#Item">QPtrCollection::Item</a> item1, <a href="qptrcollection.html#Item">QPtrCollection::Item</a> item2 )<tt> [virtual protected]</tt>
</h3>
<p> This virtual function compares two list items.
<p> Returns:
<ul>
<li> zero if <em>item1</em> == <em>item2</em>
<li> nonzero if <em>item1</em> != <em>item2</em>
</ul>
<p> This function returns <em>int</em> rather than <em>bool</em> so that
reimplementations can return three values and use it to sort by:
<p> <ul>
<li> 0 if <em>item1</em> == <em>item2</em>
<li> > 0 (positive integer) if <em>item1</em> > <em>item2</em>
<li> < 0 (negative integer) if <em>item1</em> < <em>item2</em>
</ul>
<p> <a href="#inSort">inSort</a>() requires that <a href="#compareItems">compareItems</a>() is implemented as described here.
<p> This function should not modify the list because some const functions
call compareItems().
<p> The default implementation compares the pointers.
<h3 class=fn>uint <a name="contains"></a>QPtrList::contains ( const type * item ) const
</h3>
Counts and returns the number of occurrences of <em>item</em> in the list.
<p> The <a href="#compareItems">compareItems</a>() function is called when looking for the <em>item</em>
in the list. If compareItems() is not reimplemented, it is more
efficient to call <a href="#containsRef">containsRef</a>().
<p> This function does not affect the current list item.
<p> <p>See also <a href="#containsRef">containsRef</a>() and <a href="#compareItems">compareItems</a>().
<h3 class=fn>uint <a name="containsRef"></a>QPtrList::containsRef ( const type * item ) const
</h3>
Counts and returns the number of occurrences of <em>item</em> in the list.
<p> Calling this function is much faster than <a href="#contains">contains</a>() because contains()
compares <em>item</em> with each list item using <a href="#compareItems">compareItems</a>().
This function only compares the pointers.
<p> This function does not affect the current list item.
<p> <p>See also <a href="#contains">contains</a>().
<h3 class=fn>uint <a name="count"></a>QPtrList::count () const<tt> [virtual]</tt>
</h3>
Returns the number of items in the list.
<p>See also <a href="#isEmpty">isEmpty</a>().
<p>Examples: <a href="customlayout-example.html#x1812">customlayout/border.cpp</a>, <a href="customlayout-example.html#x1830">customlayout/card.cpp</a>, <a href="customlayout-example.html#x1789">customlayout/flow.cpp</a>, <a href="fileiconview-example.html#x1580">fileiconview/qfileiconview.cpp</a>, <a href="grapher-nsplugin-example.html#x2623">grapher/grapher.cpp</a>, <a href="mdi-example.html#x1171">mdi/application.cpp</a> and <a href="qwerty-example.html#x651">qwerty/qwerty.cpp</a>.
<p>Reimplemented from <a href="qptrcollection.html#count">QPtrCollection</a>.
<h3 class=fn>type * <a name="current"></a>QPtrList::current () const
</h3>
Returns a pointer to the current list item. The current item may be
null (implies that the current index is -1).
<p>See also <a href="#at">at</a>().
<h3 class=fn>QLNode * <a name="currentNode"></a>QPtrList::currentNode () const
</h3>
Returns a pointer to the current list node.
<p> The node can be kept and removed later using <a href="#removeNode">removeNode</a>().
The advantage is that the item can be removed directly without
searching the list.
<p> <b>Warning:</b> Do not call this function unless you are an expert.
<p> <p>See also <a href="#removeNode">removeNode</a>(), <a href="#takeNode">takeNode</a>() and <a href="#current">current</a>().
<h3 class=fn>int <a name="find"></a>QPtrList::find ( const type * item )
</h3>
Finds the first occurrence of <em>item</em> in the list.
<p> If the item is found, the list sets the current item to point to
the found item and returns the index of this item.
If the item is not found, the list sets the current item to null,
the current index to -1, and returns -1.
<p> The <a href="#compareItems">compareItems</a>() function is called when searching for the item
in the list. If compareItems() is not reimplemented, it is more
efficient to call <a href="#findRef">findRef</a>().
<p> <p>See also <a href="#findNext">findNext</a>(), <a href="#findRef">findRef</a>(), <a href="#compareItems">compareItems</a>() and <a href="#current">current</a>().
<h3 class=fn>int <a name="findNext"></a>QPtrList::findNext ( const type * item )
</h3>
Finds the next occurrence of <em>item</em> in the list, starting from
the current list item.
<p> If the item is found, the list sets the current item to point to
the found item and returns the index of this item.
If the item is not found, the list sets the current item to null,
the current index to -1, and returns -1.
<p> The <a href="#compareItems">compareItems</a>() function is called when searching for the item
in the list. If compareItems() is not reimplemented, it is more
efficient to call <a href="#findNextRef">findNextRef</a>().
<p> <p>See also <a href="#find">find</a>(), <a href="#findNextRef">findNextRef</a>(), <a href="#compareItems">compareItems</a>() and <a href="#current">current</a>().
<h3 class=fn>int <a name="findNextRef"></a>QPtrList::findNextRef ( const type * item )
</h3>
Finds the next occurrence of <em>item</em> in the list, starting from the
current list item.
<p> If the item is found, the list sets the current item to point to
the found item and returns the index of this item.
If the item is not found, the list sets the current item to null,
the current index to -1, and returns -1.
<p> Calling this function is much faster than <a href="#findNext">findNext</a>() because findNext()
compares <em>item</em> with each list item using <a href="#compareItems">compareItems</a>().
This function only compares the pointers.
<p> <p>See also <a href="#findRef">findRef</a>(), <a href="#findNext">findNext</a>() and <a href="#current">current</a>().
<h3 class=fn>int <a name="findRef"></a>QPtrList::findRef ( const type * item )
</h3>
Finds the first occurrence of <em>item</em> in the list.
<p> If the item is found, the list sets the current item to point to
the found item and returns the index of this item.
If the item is not found, the list sets the current item to null,
the current index to -1, and returns -1.
<p> Calling this function is much faster than <a href="#find">find</a>() because find()
compares <em>item</em> with each list item using <a href="#compareItems">compareItems</a>().
This function only compares the pointers.
<p> <p>See also <a href="#findNextRef">findNextRef</a>(), <a href="#find">find</a>() and <a href="#current">current</a>().
<h3 class=fn>type * <a name="first"></a>QPtrList::first ()
</h3>
Returns a pointer to the first item in the list and makes this the
current list item, or null if the list is empty.
<p>See also <a href="#getFirst">getFirst</a>(), <a href="#last">last</a>(), <a href="#next">next</a>(), <a href="#prev">prev</a>() and <a href="#current">current</a>().
<p>Examples: <a href="grapher-nsplugin-example.html#x2624">grapher/grapher.cpp</a>, <a href="listviews-example.html#x1201">listviews/listviews.h</a> and <a href="showimg-example.html#x443">showimg/showimg.cpp</a>.
<h3 class=fn>type * <a name="getFirst"></a>QPtrList::getFirst () const
</h3>
Returns a pointer to the first item in the list, or null if the
list is empty.
<p> This function does not affect the current list item.
<p> <p>See also <a href="#first">first</a>() and <a href="#getLast">getLast</a>().
<h3 class=fn>type * <a name="getLast"></a>QPtrList::getLast () const
</h3>
Returns a pointer to the last item in the list, or null if the
list is empty.
<p> This function does not affect the current list item.
<p> <p>See also <a href="#last">last</a>() and <a href="#getFirst">getFirst</a>().
<h3 class=fn>void <a name="inSort"></a>QPtrList::inSort ( const type * item )
</h3>
Inserts the <em>item</em> at its sorted position in the list.
<p> The sort order depends on the virtual <a href="#compareItems">compareItems</a>() function.
All items must be inserted with <a href="#inSort">inSort</a>() to maintain the sorting order.
<p> The inserted item becomes the current list item.
<p> The <em>item</em> must not be a null pointer.
<p> Please note that inSort() is slow. If you want to insert lots of items
in a list and sort after inserting, you should use <a href="#sort">sort</a>().
inSort() takes up to O(n) compares. That means inserting n items in
your list will need O(n^2) compares whereas sort() only needs O(n*log n)
for the same task. So use inSort() only if you already have a presorted
list and want to insert just a few additional items.
<p> <p>See also <a href="#insert">insert</a>(), <a href="#compareItems">compareItems</a>(), <a href="#current">current</a>() and <a href="#sort">sort</a>().
<h3 class=fn>bool <a name="insert"></a>QPtrList::insert ( uint index, const type * item )
</h3>
Inserts the <em>item</em> at the position <em>index</em> in the list.
<p> Returns TRUE if successful or FALSE if <em>index</em> is out of range.
The valid range is 0 to <a href="#count">count</a>() (inclusively).
The item is appended if <em>index</em> == count().
<p> The inserted item becomes the current list item.
<p> The <em>item</em> must not be a null pointer.
<p> <p>See also <a href="#append">append</a>() and <a href="#current">current</a>().
<h3 class=fn>bool <a name="isEmpty"></a>QPtrList::isEmpty () const
</h3>
Returns TRUE if the list is empty; otherwise returns FALSE.
<p> <p>See also <a href="#count">count</a>().
<h3 class=fn>type * <a name="last"></a>QPtrList::last ()
</h3>
Returns a pointer to the last item in the list and makes this the
current list item, or null if the list is empty.
<p>See also <a href="#getLast">getLast</a>(), <a href="#first">first</a>(), <a href="#next">next</a>(), <a href="#prev">prev</a>() and <a href="#current">current</a>().
<h3 class=fn>type * <a name="next"></a>QPtrList::next ()
</h3>
Returns a pointer to the item succeeding the current item.
Returns null if the current item is null or equal to the last item.
<p> Makes the succeeding item current. If the current item before this
function call was the last item, the current item will be set to null.
If the current item was null, this function does nothing.
<p> <p>See also <a href="#first">first</a>(), <a href="#last">last</a>(), <a href="#prev">prev</a>() and <a href="#current">current</a>().
<p>Examples: <a href="grapher-nsplugin-example.html#x2625">grapher/grapher.cpp</a>, <a href="listviews-example.html#x1202">listviews/listviews.h</a> and <a href="showimg-example.html#x444">showimg/showimg.cpp</a>.
<h3 class=fn><a href="qptrlist.html">QPtrList</a><type> & <a name="operator-eq"></a>QPtrList::operator= ( const <a href="qptrlist.html">QPtrList</a><type> & list )
</h3>
Assigns <em>list</em> to this list and returns a reference to this list.
<p> This list is first cleared and then each item in <em>list</em> is
<a href="#append">appended</a> to this list. Only the pointers are copied
(shallow copy) unless <a href="qptrcollection.html#newItem">newItem</a>() has been reimplemented().
<h3 class=fn>bool <a name="operator-eq-eq"></a>QPtrList::operator== ( const <a href="qptrlist.html">QPtrList</a><type> & list ) const
</h3>
<p> Compares this list with <em>list</em>. Returns TRUE if the lists
contain the same data; otherwise returns FALSE.
<h3 class=fn>void <a name="prepend"></a>QPtrList::prepend ( const type * item )
</h3>
<p> Inserts the <em>item</em> at the start of the list.
<p> The inserted item becomes the current list item.
This is equivalent to <tt>insert( 0, item )</tt>.
<p> The <em>item</em> must not be a null pointer.
<p> <p>See also <a href="#append">append</a>(), <a href="#insert">insert</a>() and <a href="#current">current</a>().
<h3 class=fn>type * <a name="prev"></a>QPtrList::prev ()
</h3>
Returns a pointer to the item preceding the current item.
Returns null if the current item is null or equal to the first item.
<p> Makes the preceding item current. If the current item before this
function call was the first item, the current item will be set to null.
If the current item was null, this function does nothing.
<p> <p>See also <a href="#first">first</a>(), <a href="#last">last</a>(), <a href="#next">next</a>() and <a href="#current">current</a>().
<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="read"></a>QPtrList::read ( <a href="qdatastream.html">QDataStream</a> & s, <a href="qptrcollection.html#Item">QPtrCollection::Item</a> & item )<tt> [virtual protected]</tt>
</h3>
<p> Reads a list item from the stream <em>s</em> and returns a reference to
the stream.
<p> The default implementation sets <em>item</em> to 0.
<p> <p>See also <a href="#write">write</a>().
<h3 class=fn>bool <a name="remove"></a>QPtrList::remove ( uint index )
</h3>
Removes the item at position <em>index</em> in the list.
<p> Returns TRUE if successful, or FALSE if <em>index</em> is out of range.
The valid range is <tt>0..(count() - 1)</tt> inclusive.
<p> The removed item is deleted if <a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled.
<p> The item after the removed item becomes the new current list item if
the removed item is not the last item in the list. If the last item
is removed, the new last item becomes the current item.
<p> All list iterators that refer to the removed item will be set to point
to the new current item.
<p> <p>See also <a href="#take">take</a>(), <a href="#clear">clear</a>(), <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>(), <a href="#current">current</a>() and <a href="#removeRef">removeRef</a>().
<h3 class=fn>bool <a name="remove-2"></a>QPtrList::remove ()
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Removes the current list item.
<p> Returns TRUE if successful, or FALSE if the current item is null.
<p> The removed item is deleted if <a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled.
<p> The item after the removed item becomes the new current list item if
the removed item is not the last item in the list. If the last item
is removed, the new last item becomes the current item. The current
item is set to null if the list becomes empty.
<p> All list iterators that refer to the removed item will be set to point
to the new current item.
<p> <p>See also <a href="#take">take</a>(), <a href="#clear">clear</a>(), <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>(), <a href="#current">current</a>() and <a href="#removeRef">removeRef</a>().
<h3 class=fn>bool <a name="remove-3"></a>QPtrList::remove ( const type * item )
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Removes the first occurrence of <em>item</em> from the list.
<p> Returns TRUE if successful, or FALSE if the item could not be found in the
list.
<p> The removed item is deleted if <a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled.
<p> The <a href="#compareItems">compareItems</a>() function is called when searching for the item
in the list. If compareItems() is not reimplemented, it is more
efficient to call <a href="#removeRef">removeRef</a>().
<p> The item after the removed item becomes the new current list item if
the removed item is not the last item in the list. If the last item
is removed, the new last item becomes the current item. The current
item is set to null if the list becomes empty.
<p> All list iterators that refer to the removed item will be set to point
to the new current item.
<p> <p>See also <a href="#removeRef">removeRef</a>(), <a href="#take">take</a>(), <a href="#clear">clear</a>(), <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>(), <a href="#compareItems">compareItems</a>() and <a href="#current">current</a>().
<h3 class=fn>bool <a name="removeFirst"></a>QPtrList::removeFirst ()
</h3>
Removes the first item from the list.
Returns TRUE if successful, or FALSE if the list is empty.
<p> The removed item is deleted if <a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled.
<p> The first item in the list becomes the new current list item.
The current item is set to null if the list becomes empty.
<p> All list iterators that refer to the removed item will be set to point
to the new current item.
<p> <p>See also <a href="#removeLast">removeLast</a>(), <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>(), <a href="#current">current</a>() and <a href="#remove">remove</a>().
<h3 class=fn>bool <a name="removeLast"></a>QPtrList::removeLast ()
</h3>
Removes the last item from the list.
Returns TRUE if successful, or FALSE if the list is empty.
<p> The removed item is deleted if <a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled.
<p> The last item in the list becomes the new current list item.
The current item is set to null if the list becomes empty.
<p> All list iterators that refer to the removed item will be set to point
to the new current item.
<p> <p>See also <a href="#removeFirst">removeFirst</a>(), <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>() and <a href="#current">current</a>().
<h3 class=fn>void <a name="removeNode"></a>QPtrList::removeNode ( QLNode * node )
</h3>
Removes the <em>node</em> from the list.
<p> This node must exist in the list, otherwise the program may crash.
<p> The removed item is deleted if <a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled.
<p> The first item in the list will become the new current list item.
The current item is set to null if the list becomes empty.
<p> All list iterators that refer to the removed item will be set to point to
the item succeeding this item or to the preceding item if the removed item
was the last item.
<p> <b>Warning:</b> Do not call this function unless you are an expert.
<p> <p>See also <a href="#takeNode">takeNode</a>(), <a href="#currentNode">currentNode</a>(), <a href="#remove">remove</a>() and <a href="#removeRef">removeRef</a>().
<h3 class=fn>bool <a name="removeRef"></a>QPtrList::removeRef ( const type * item )
</h3>
Removes the first occurrence of <em>item</em> from the list.
<p> Returns TRUE if successful, or FALSE if the item cannot be found in the
list.
<p> The removed item is deleted if <a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled.
<p> The list is scanned until the pointer <em>item</em> is found. It is removed
if it is found.
<p> Equivalent to:
<pre>
if ( list.findRef( item ) != -1 )
list.remove();
</pre>
<p> The item after the removed item becomes the new current list item if
the removed item is not the last item in the list. If the last item
is removed, the new last item becomes the current item. The current
item is set to null if the list becomes empty.
<p> All list iterators that refer to the removed item will be set to point
to the new current item.
<p> <p>See also <a href="#remove">remove</a>(), <a href="#clear">clear</a>(), <a href="qptrcollection.html#setAutoDelete">setAutoDelete</a>() and <a href="#current">current</a>().
<h3 class=fn>void <a name="setAutoDelete"></a>QPtrCollection::setAutoDelete ( bool enable )
</h3>
<p> Sets the collection to auto-delete its contents if <em>enable</em> is TRUE
and to never delete them if <em>enable</em> is FALSE.
<p> If auto-deleting is turned on, all the items in a collection are
deleted when the collection itself is deleted. This is convenient if
the collection has the only pointer to the items.
<p> The default setting is FALSE, for safety. If you turn it on, be
careful about copying the collection - you might find yourself with
two collections deleting the same items.
<p> Note that the auto-delete setting may also affect other functions in
subclasses. For example, a subclass that has a <a href="#remove">remove</a>() function
will remove the item from its data structure, and if auto-delete is
enabled, will also delete the item.
<p> <p>See also <a href="qptrcollection.html#autoDelete">autoDelete</a>().
<p>Examples: <a href="grapher-nsplugin-example.html#x2621">grapher/grapher.cpp</a>, <a href="scribble-example.html#x539">scribble/scribble.cpp</a> and <a href="bigtable-example.html#x380">table/bigtable/main.cpp</a>.
<h3 class=fn>void <a name="sort"></a>QPtrList::sort ()
</h3>
<p> Sorts the list by the result of the virtual <a href="#compareItems">compareItems</a>() function.
<p> The Heap-Sort algorithm is used for sorting. It sorts n items with
O(n*log n) comparisons. This is the asymptotic optimal solution of the
sorting problem.
<p> If the items in your list support operator< and operator==, you
might be better off with QSortedList because it implements the
compareItems() function for you using these two operators.
<p> <p>See also <a href="#inSort">inSort</a>().
<h3 class=fn>type * <a name="take"></a>QPtrList::take ( uint index )
</h3>
Takes the item at position <em>index</em> out of the list without
deleting it (even if <a href="qptrcollection.html#setAutoDelete">auto-deletion</a>
is enabled).
<p> Returns a pointer to the item taken out of the list, or null if
the index is out of range.
The valid range is <tt>0..(count() - 1)</tt> inclusive.
<p> The item after the removed item becomes the new current list item if
the removed item is not the last item in the list. If the last item
is removed, the new last item becomes the current item. The current
item is set to null if the list becomes empty.
<p> All list iterators that refer to the taken item will be set to point to
the new current item.
<p> <p>See also <a href="#remove">remove</a>(), <a href="#clear">clear</a>() and <a href="#current">current</a>().
<p>Examples: <a href="customlayout-example.html#x1813">customlayout/border.cpp</a>, <a href="customlayout-example.html#x1831">customlayout/card.cpp</a> and <a href="customlayout-example.html#x1790">customlayout/flow.cpp</a>.
<h3 class=fn>type * <a name="take-2"></a>QPtrList::take ()
</h3>
This is an overloaded member function, provided for convenience. It behaves essentially like the above function.
<p> Takes the current item out of the list without deleting it (even if
<a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled).
Returns a pointer to the item taken out of the list, or null if
the current item is null.
<p> The item after the removed item becomes the new current list item if
the removed item is not the last item in the list. If the last item
is removed, the new last item becomes the current item. The current
item is set to null if the list becomes empty.
<p> All list iterators that refer to the taken item will be set to point to
the new current item.
<p> <p>See also <a href="#remove">remove</a>(), <a href="#clear">clear</a>() and <a href="#current">current</a>().
<h3 class=fn>type * <a name="takeNode"></a>QPtrList::takeNode ( QLNode * node )
</h3>
Takes the <em>node</em> out of the list without deleting its item (even if
<a href="qptrcollection.html#setAutoDelete">auto-deletion</a> is enabled).
Returns a pointer to the item taken out of the list.
<p> This node must exist in the list, otherwise the program may crash.
<p> The first item in the list becomes the new current list item.
<p> All list iterators that refer to the taken item will be set to point to
the item succeeding this item or to the preceding item if the taken item
was the last item.
<p> <b>Warning:</b> Do not call this function unless you are an expert.
<p> <p>See also <a href="#removeNode">removeNode</a>() and <a href="#currentNode">currentNode</a>().
<h3 class=fn>void <a name="toVector"></a>QPtrList::toVector ( QGVector * vec ) const
</h3>
Stores all list items in the vector <em>vec</em>.
<p> The vector must be have the same item type, otherwise the result
will be undefined.
<h3 class=fn><a href="qdatastream.html">QDataStream</a> & <a name="write"></a>QPtrList::write ( <a href="qdatastream.html">QDataStream</a> & s, <a href="qptrcollection.html#Item">QPtrCollection::Item</a> item ) const<tt> [virtual protected]</tt>
</h3>
<p> Writes a list item, <em>item</em> to the stream <em>s</em> and returns a
reference to the stream.
<p> The default implementation does nothing.
<p> <p>See also <a href="#read">read</a>().
<!-- eof -->
<hr><p>
This file is part of the <a href="index.html">Qt toolkit</a>.
Copyright © 1995-2001
<a href="http://www.trolltech.com/">Trolltech</a>. All Rights Reserved.<p><address><hr><div align=center>
<table width=100% cellspacing=0 border=0><tr>
<td>Copyright © 2001
<a href="http://www.trolltech.com">Trolltech</a><td><a href="http://www.trolltech.com/trademarks.html">Trademarks</a>
<td align=right><div align=right>Qt version 3.0.2</div>
</table></div></address></body>
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