<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!-- /home/espenr/tmp/qt-3.3.8-espenr-2499/qt-x11-free-3.3.8/doc/tqptrdict.doc:41 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>TQPtrDict Class</title> <style type="text/css"><!-- fn { margin-left: 1cm; text-indent: -1cm; } a:link { color: #004faf; text-decoration: none } a:visited { color: #672967; text-decoration: none } body { background: #ffffff; color: black; } --></style> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr bgcolor="#E5E5E5"> <td valign=center> <a href="index.html"> <font color="#004faf">Home</font></a> | <a href="classes.html"> <font color="#004faf">All Classes</font></a> | <a href="mainclasses.html"> <font color="#004faf">Main Classes</font></a> | <a href="annotated.html"> <font color="#004faf">Annotated</font></a> | <a href="groups.html"> <font color="#004faf">Grouped Classes</font></a> | <a href="functions.html"> <font color="#004faf">Functions</font></a> </td> <td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>TQPtrDict Class Reference</h1> <p>The TQPtrDict class is a template class that provides a dictionary based on void* keys. <a href="#details">More...</a> <p><tt>#include <<a href="tqptrdict-h.html">tqptrdict.h</a>></tt> <p>Inherits <a href="tqptrcollection.html">TQPtrCollection</a>. <p><a href="tqptrdict-members.html">List of all member functions.</a> <h2>Public Members</h2> <ul> <li class=fn><a href="#TQPtrDict"><b>TQPtrDict</b></a> ( int size = 17 )</li> <li class=fn><a href="#TQPtrDict-2"><b>TQPtrDict</b></a> ( const TQPtrDict<type> & dict )</li> <li class=fn><a href="#~TQPtrDict"><b>~TQPtrDict</b></a> ()</li> <li class=fn>TQPtrDict<type> & <a href="#operator-eq"><b>operator=</b></a> ( const TQPtrDict<type> & dict )</li> <li class=fn>virtual uint <a href="#count"><b>count</b></a> () const</li> <li class=fn>uint <a href="#size"><b>size</b></a> () const</li> <li class=fn>bool <a href="#isEmpty"><b>isEmpty</b></a> () const</li> <li class=fn>void <a href="#insert"><b>insert</b></a> ( void * key, const type * item )</li> <li class=fn>void <a href="#replace"><b>replace</b></a> ( void * key, const type * item )</li> <li class=fn>bool <a href="#remove"><b>remove</b></a> ( void * key )</li> <li class=fn>type * <a href="#take"><b>take</b></a> ( void * key )</li> <li class=fn>type * <a href="#find"><b>find</b></a> ( void * key ) const</li> <li class=fn>type * <a href="#operator[]"><b>operator[]</b></a> ( void * key ) const</li> <li class=fn>virtual void <a href="#clear"><b>clear</b></a> ()</li> <li class=fn>void <a href="#resize"><b>resize</b></a> ( uint newsize )</li> <li class=fn>void <a href="#statistics"><b>statistics</b></a> () const</li> </ul> <h2>Important Inherited Members</h2> <ul> <li class=fn>bool <a href="#autoDelete"><b>autoDelete</b></a> () const</li> <li class=fn>void <a href="#setAutoDelete"><b>setAutoDelete</b></a> ( bool enable )</li> </ul> <h2>Protected Members</h2> <ul> <li class=fn>virtual TQDataStream & <a href="#read"><b>read</b></a> ( TQDataStream & s, TQPtrCollection::Item & item )</li> <li class=fn>virtual TQDataStream & <a href="#write"><b>write</b></a> ( TQDataStream & s, TQPtrCollection::Item ) const</li> </ul> <hr><a name="details"></a><h2>Detailed Description</h2> The TQPtrDict class is a template class that provides a dictionary based on void* keys. <p> <p> <p> TQPtrDict is implemented as a template class. Define a template instance TQPtrDict<X> to create a dictionary that operates on pointers to X (X*). <p> A dictionary is a collection of key-value pairs. The key is a void* used for insertion, removal and lookup. The value is a pointer. Dictionaries provide very fast insertion and lookup. <p> Example: <pre> TQPtrDict<char> fields; // void* keys, char* values <a href="tqlineedit.html">TQLineEdit</a> *le1 = new <a href="tqlineedit.html">TQLineEdit</a>( this ); le1-><a href="tqlineedit.html#setText">setText</a>( "Simpson" ); <a href="tqlineedit.html">TQLineEdit</a> *le2 = new <a href="tqlineedit.html">TQLineEdit</a>( this ); le2-><a href="tqlineedit.html#setText">setText</a>( "Homer" ); <a href="tqlineedit.html">TQLineEdit</a> *le3 = new <a href="tqlineedit.html">TQLineEdit</a>( this ); le3-><a href="tqlineedit.html#setText">setText</a>( "45" ); fields.<a href="#insert">insert</a>( le1, "Surname" ); fields.<a href="#insert">insert</a>( le2, "Forename" ); fields.<a href="#insert">insert</a>( le3, "Age" ); <a href="tqptrdictiterator.html">TQPtrDictIterator</a><char> it( fields ); for( ; it.<a href="tqptrdictiterator.html#current">current</a>(); ++it ) cout << it.<a href="tqptrdictiterator.html#current">current</a>() << endl; cout << endl; if ( fields[le1] ) // Prints "Surname: Simpson" cout << fields[le1] << ": " << le1-><a href="tqlineedit.html#text">text</a>() << endl; if ( fields[le2] ) // Prints "Forename: Homer" cout << fields[le2] << ": " << le2-><a href="tqlineedit.html#text">text</a>() << endl; fields.<a href="#remove">remove</a>( le1 ); // Removes le1 from the dictionary cout << le1-><a href="tqlineedit.html#text">text</a>() << endl; // Prints "Simpson" </pre> In this example we use a dictionary to add an extra property (a char*) to the line edits we're using. <p> See <a href="tqdict.html">TQDict</a> for full details, including the choice of dictionary size, and how deletions are handled. <p> <p>See also <a href="tqptrdictiterator.html">TQPtrDictIterator</a>, <a href="tqdict.html">TQDict</a>, <a href="tqasciidict.html">TQAsciiDict</a>, <a href="tqintdict.html">TQIntDict</a>, <a href="collection.html">Collection Classes</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="TQPtrDict"></a>TQPtrDict::TQPtrDict ( int size = 17 ) </h3> <p> Constructs a dictionary using an internal hash array with the size <em>size</em>. <p> Setting <em>size</em> to a suitably large <a href="primes.html#prime">prime</a> number (equal to or greater than the expected number of entries) makes the hash distribution better and improves lookup performance. <h3 class=fn><a name="TQPtrDict-2"></a>TQPtrDict::TQPtrDict ( const <a href="tqptrdict.html">TQPtrDict</a><type> & dict ) </h3> <p> Constructs a copy of <em>dict</em>. <p> Each item in <em>dict</em> is inserted into this dictionary. Only the pointers are copied (shallow copy). <h3 class=fn><a name="~TQPtrDict"></a>TQPtrDict::~TQPtrDict () </h3> <p> Removes all items from the dictionary and destroys it. <p> All iterators that access this dictionary will be reset. <p> <p>See also <a href="tqptrcollection.html#setAutoDelete">setAutoDelete</a>(). <h3 class=fn>bool <a name="autoDelete"></a>TQPtrCollection::autoDelete () const </h3> <p> Returns the setting of the auto-delete option. The default is FALSE. <p> <p>See also <a href="tqptrcollection.html#setAutoDelete">setAutoDelete</a>(). <h3 class=fn>void <a name="clear"></a>TQPtrDict::clear ()<tt> [virtual]</tt> </h3> <p> Removes all items from the dictionary. <p> The removed items are deleted if <a href="tqptrcollection.html#setAutoDelete">auto-deletion</a> is enabled. <p> All dictionary iterators that access this dictionary will be reset. <p> <p>See also <a href="#remove">remove</a>(), <a href="#take">take</a>(), and <a href="tqptrcollection.html#setAutoDelete">setAutoDelete</a>(). <p>Reimplemented from <a href="tqptrcollection.html#clear">TQPtrCollection</a>. <h3 class=fn>uint <a name="count"></a>TQPtrDict::count () const<tt> [virtual]</tt> </h3> <p> Returns the number of items in the dictionary. <p> <p>See also <a href="#isEmpty">isEmpty</a>(). <p>Reimplemented from <a href="tqptrcollection.html#count">TQPtrCollection</a>. <h3 class=fn>type * <a name="find"></a>TQPtrDict::find ( void * key ) const </h3> <p> Returns the item associated with <em>key</em>, or 0 if the key does not exist in the dictionary. <p> If there are two or more items with equal keys, then the most recently inserted item will be found. <p> Equivalent to operator[]. <p> <p>See also <a href="#operator[]">operator[]</a>(). <h3 class=fn>void <a name="insert"></a>TQPtrDict::insert ( void * key, const type * item ) </h3> <p> Inserts the <em>key</em> with the <em>item</em> into the dictionary. <p> Multiple items can have the same key, in which case only the last item will be accessible using <a href="#operator[]">operator[]</a>(). <p> <em>item</em> may not be 0. <p> <p>See also <a href="#replace">replace</a>(). <h3 class=fn>bool <a name="isEmpty"></a>TQPtrDict::isEmpty () const </h3> <p> Returns TRUE if the dictionary is empty; otherwise returns FALSE. <p> <p>See also <a href="#count">count</a>(). <h3 class=fn><a href="tqptrdict.html">TQPtrDict</a><type> & <a name="operator-eq"></a>TQPtrDict::operator= ( const <a href="tqptrdict.html">TQPtrDict</a><type> & dict ) </h3> <p> Assigns <em>dict</em> to this dictionary and returns a reference to this dictionary. <p> This dictionary is first cleared and then each item in <em>dict</em> is inserted into the dictionary. Only the pointers are copied (shallow copy), unless <a href="tqptrcollection.html#newItem">newItem</a>() has been reimplemented. <h3 class=fn>type * <a name="operator[]"></a>TQPtrDict::operator[] ( void * key ) const </h3> <p> Returns the item associated with <em>key</em>, or 0 if the key does not exist in the dictionary. <p> If there are two or more items with equal keys, then the most recently inserted item will be found. <p> Equivalent to the <a href="#find">find</a>() function. <p> <p>See also <a href="#find">find</a>(). <h3 class=fn><a href="tqdatastream.html">TQDataStream</a> & <a name="read"></a>TQPtrDict::read ( <a href="tqdatastream.html">TQDataStream</a> & s, <a href="tqptrcollection.html#Item">TQPtrCollection::Item</a> & item )<tt> [virtual protected]</tt> </h3> <p> Reads a dictionary 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>TQPtrDict::remove ( void * key ) </h3> <p> Removes the item associated with <em>key</em> from the dictionary. Returns TRUE if successful, i.e. if <em>key</em> is in the dictionary; otherwise returns FALSE. <p> If there are two or more items with equal keys, then the most recently inserted item will be removed. <p> The removed item is deleted if <a href="tqptrcollection.html#setAutoDelete">auto-deletion</a> is enabled. <p> All dictionary iterators that refer to the removed item will be set to point to the next item in the dictionary traversal order. <p> <p>See also <a href="#take">take</a>(), <a href="#clear">clear</a>(), and <a href="tqptrcollection.html#setAutoDelete">setAutoDelete</a>(). <h3 class=fn>void <a name="replace"></a>TQPtrDict::replace ( void * key, const type * item ) </h3> <p> If the dictionary has key <em>key</em>, this key's item is replaced with <em>item</em>. If the dictionary doesn't contain key <em>key</em>, <em>item</em> is inserted into the dictionary using key <em>key</em>. <p> <em>item</em> may not be 0. <p> Equivalent to <pre> TQPtrDict<ItemType> dict; ... if ( dict.<a href="#find">find</a>( key ) ) dict.<a href="#remove">remove</a>( key ); dict.<a href="#insert">insert</a>( key, item ); </pre> <p> If there are two or more items with equal keys, then the most recently inserted item will be replaced. <p> <p>See also <a href="#insert">insert</a>(). <h3 class=fn>void <a name="resize"></a>TQPtrDict::resize ( uint newsize ) </h3> <p> Changes the size of the hash table to <em>newsize</em>. The contents of the dictionary are preserved, but all iterators on the dictionary become invalid. <h3 class=fn>void <a name="setAutoDelete"></a>TQPtrCollection::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="tqptrcollection.html#autoDelete">autoDelete</a>(). <p>Examples: <a href="grapher-nsplugin-example.html#x2769">grapher/grapher.cpp</a>, <a href="scribble-example.html#x924">scribble/scribble.cpp</a>, and <a href="bigtable-example.html#x1291">table/bigtable/main.cpp</a>. <h3 class=fn>uint <a name="size"></a>TQPtrDict::size () const </h3> <p> Returns the size of the internal hash table (as specified in the constructor). <p> <p>See also <a href="#count">count</a>(). <h3 class=fn>void <a name="statistics"></a>TQPtrDict::statistics () const </h3> <p> Debugging-only function that prints out the dictionary distribution using <a href="ntqapplication.html#qDebug">tqDebug</a>(). <h3 class=fn>type * <a name="take"></a>TQPtrDict::take ( void * key ) </h3> <p> Takes the item associated with <em>key</em> out of the dictionary without deleting it (even if <a href="tqptrcollection.html#setAutoDelete">auto-deletion</a> is enabled). <p> If there are two or more items with equal keys, then the most recently inserted item will be removed. <p> Returns a pointer to the item taken out, or 0 if the key does not exist in the dictionary. <p> All dictionary iterators that refer to the taken item will be set to point to the next item in the dictionary traversal order. <p> <p>See also <a href="#remove">remove</a>(), <a href="#clear">clear</a>(), and <a href="tqptrcollection.html#setAutoDelete">setAutoDelete</a>(). <h3 class=fn><a href="tqdatastream.html">TQDataStream</a> & <a name="write"></a>TQPtrDict::write ( <a href="tqdatastream.html">TQDataStream</a> & s, <a href="tqptrcollection.html#Item">TQPtrCollection::Item</a> ) const<tt> [virtual protected]</tt> </h3> <p> Writes a dictionary item to the stream <em>s</em> and returns a reference to the stream. <p> <p>See also <a href="#read">read</a>(). <!-- eof --> <hr><p> This file is part of the <a href="index.html">TQt toolkit</a>. 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