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32<td align="right" valign="center"><img src="logo32.png" align="right" width="64" height="32" border="0"></td></tr></table><h1 align=center>QLayoutIterator Class Reference</h1>
33
34<p>The QLayoutIterator class provides iterators over QLayoutItem.
35<a href="#details">More...</a>
36<p><tt>#include &lt;<a href="qlayout-h.html">qlayout.h</a>&gt;</tt>
37<p><a href="qlayoutiterator-members.html">List of all member functions.</a>
38<h2>Public Members</h2>
39<ul>
40<li class=fn><a href="#QLayoutIterator"><b>QLayoutIterator</b></a> ( QGLayoutIterator&nbsp;*&nbsp;gi )</li>
41<li class=fn><a href="#QLayoutIterator-2"><b>QLayoutIterator</b></a> ( const&nbsp;QLayoutIterator&nbsp;&amp;&nbsp;i )</li>
42<li class=fn><a href="#~QLayoutIterator"><b>~QLayoutIterator</b></a> ()</li>
43<li class=fn>QLayoutIterator &amp; <a href="#operator-eq"><b>operator=</b></a> ( const&nbsp;QLayoutIterator&nbsp;&amp;&nbsp;i )</li>
44<li class=fn>QLayoutItem * <a href="#operator++"><b>operator++</b></a> ()</li>
45<li class=fn>QLayoutItem * <a href="#current"><b>current</b></a> ()</li>
46<li class=fn>QLayoutItem * <a href="#takeCurrent"><b>takeCurrent</b></a> ()</li>
47<li class=fn>void <a href="#deleteCurrent"><b>deleteCurrent</b></a> ()</li>
48</ul>
49<hr><a name="details"></a><h2>Detailed Description</h2>
50
51
52The QLayoutIterator class provides iterators over <a href="qlayoutitem.html">QLayoutItem</a>.
53<p>
54
55<p> Use <a href="qlayoutitem.html#iterator">QLayoutItem::iterator</a>() to create an iterator over a layout.
56<p> QLayoutIterator uses <em>explicit</em> sharing with a reference count.
57If an iterator is copied and one of the copies is modified, both
58iterators will be modified.
59<p> A QLayoutIterator is not protected against changes in its layout. If
60the layout is modified or deleted the iterator will become invalid.
61It is not possible to test for validity. It is safe to delete an
62invalid layout; any other access may lead to an illegal memory
63reference and the abnormal termination of the program.
64<p> Calling <a href="#takeCurrent">takeCurrent</a>() or <a href="#deleteCurrent">deleteCurrent</a>() leaves the iterator in a
65valid state, but may invalidate any other iterators that access the
66same layout.
67<p> The following code will draw a rectangle for each layout item in
68the layout structure of the widget.
69<pre>
70 static void paintLayout( <a href="qpainter.html">QPainter</a> *p, QLayoutItem *lay )
71 {
72 QLayoutIterator it = lay-&gt;iterator();
73 <a href="qlayoutitem.html">QLayoutItem</a> *child;
74 while ( (child = it.<a href="#current">current</a>()) != 0 ) {
75 paintLayout( p, child );
76 ++it;
77 }
78 p-&gt;<a href="qpainter.html#drawRect">drawRect</a>( lay-&gt;geometry() );
79 }
80 void ExampleWidget::paintEvent( <a href="qpaintevent.html">QPaintEvent</a> * )
81 {
82 <a href="qpainter.html">QPainter</a> p( this );
83 if ( layout() )
84 paintLayout( &amp;p, layout() );
85 }
86 </pre>
87
88<p> All the functionality of QLayoutIterator is implemented by
89subclasses of <a href="qglayoutiterator.html">QGLayoutIterator</a>. QLayoutIterator itself is not
90designed to be subclassed.
91<p>See also <a href="appearance.html">Widget Appearance and Style</a> and <a href="geomanagement.html">Layout Management</a>.
92
93<hr><h2>Member Function Documentation</h2>
94<h3 class=fn><a name="QLayoutIterator"></a>QLayoutIterator::QLayoutIterator ( <a href="qglayoutiterator.html">QGLayoutIterator</a>&nbsp;*&nbsp;gi )
95</h3>
96
97<p> Constructs an iterator based on <em>gi</em>. The constructed iterator
98takes ownership of <em>gi</em> and will delete it.
99<p> This constructor is provided for layout implementors. Application
100programmers should use <a href="qlayoutitem.html#iterator">QLayoutItem::iterator</a>() to create an
101iterator over a layout.
102
103<h3 class=fn><a name="QLayoutIterator-2"></a>QLayoutIterator::QLayoutIterator ( const&nbsp;<a href="qlayoutiterator.html">QLayoutIterator</a>&nbsp;&amp;&nbsp;i )
104</h3>
105
106<p> Creates a <a href="shclass.html#shallow-copy">shallow copy</a> of <em>i</em>, i.e. if the copy is modified, then
107the original will also be modified.
108
109<h3 class=fn><a name="~QLayoutIterator"></a>QLayoutIterator::~QLayoutIterator ()
110</h3>
111
112<p> Destroys the iterator.
113
114<h3 class=fn><a href="qlayoutitem.html">QLayoutItem</a>&nbsp;* <a name="current"></a>QLayoutIterator::current ()
115</h3>
116
117<p> Returns the current item, or 0 if there is no current item.
118
119<h3 class=fn>void <a name="deleteCurrent"></a>QLayoutIterator::deleteCurrent ()
120</h3>
121
122<p> Removes and deletes the current child item from the layout and
123moves the iterator to the next item. This iterator will still be
124valid, but any other iterator over the same layout may become
125invalid.
126
127<h3 class=fn><a href="qlayoutitem.html">QLayoutItem</a>&nbsp;* <a name="operator++"></a>QLayoutIterator::operator++ ()
128</h3>
129
130<p> Moves the iterator to the next child item and returns that item,
131or 0 if there is no such item.
132
133<h3 class=fn><a href="qlayoutiterator.html">QLayoutIterator</a>&nbsp;&amp; <a name="operator-eq"></a>QLayoutIterator::operator= ( const&nbsp;<a href="qlayoutiterator.html">QLayoutIterator</a>&nbsp;&amp;&nbsp;i )
134</h3>
135
136<p> Assigns <em>i</em> to this iterator and returns a reference to this
137iterator.
138
139<h3 class=fn><a href="qlayoutitem.html">QLayoutItem</a>&nbsp;* <a name="takeCurrent"></a>QLayoutIterator::takeCurrent ()
140</h3>
141
142<p> Removes the current child item from the layout without deleting
143it, and moves the iterator to the next item. Returns the removed
144item, or 0 if there was no item to be removed. This iterator will
145still be valid, but any other iterator over the same layout may
146become invalid.
147
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