<!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/src/kernel/qabstractlayout.cpp:1569 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>QLayoutIterator 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>QLayoutIterator Class Reference</h1> <p>The QLayoutIterator class provides iterators over QLayoutItem. <a href="#details">More...</a> <p><tt>#include <<a href="qlayout-h.html">qlayout.h</a>></tt> <p><a href="qlayoutiterator-members.html">List of all member functions.</a> <h2>Public Members</h2> <ul> <li class=fn><a href="#QLayoutIterator"><b>QLayoutIterator</b></a> ( QGLayoutIterator * gi )</li> <li class=fn><a href="#QLayoutIterator-2"><b>QLayoutIterator</b></a> ( const QLayoutIterator & i )</li> <li class=fn><a href="#~QLayoutIterator"><b>~QLayoutIterator</b></a> ()</li> <li class=fn>QLayoutIterator & <a href="#operator-eq"><b>operator=</b></a> ( const QLayoutIterator & i )</li> <li class=fn>QLayoutItem * <a href="#operator++"><b>operator++</b></a> ()</li> <li class=fn>QLayoutItem * <a href="#current"><b>current</b></a> ()</li> <li class=fn>QLayoutItem * <a href="#takeCurrent"><b>takeCurrent</b></a> ()</li> <li class=fn>void <a href="#deleteCurrent"><b>deleteCurrent</b></a> ()</li> </ul> <hr><a name="details"></a><h2>Detailed Description</h2> The QLayoutIterator class provides iterators over <a href="qlayoutitem.html">QLayoutItem</a>. <p> <p> Use <a href="qlayoutitem.html#iterator">QLayoutItem::iterator</a>() to create an iterator over a layout. <p> QLayoutIterator uses <em>explicit</em> sharing with a reference count. If an iterator is copied and one of the copies is modified, both iterators will be modified. <p> A QLayoutIterator is not protected against changes in its layout. If the layout is modified or deleted the iterator will become invalid. It is not possible to test for validity. It is safe to delete an invalid layout; any other access may lead to an illegal memory reference and the abnormal termination of the program. <p> Calling <a href="#takeCurrent">takeCurrent</a>() or <a href="#deleteCurrent">deleteCurrent</a>() leaves the iterator in a valid state, but may invalidate any other iterators that access the same layout. <p> The following code will draw a rectangle for each layout item in the layout structure of the widget. <pre> static void paintLayout( <a href="qpainter.html">QPainter</a> *p, QLayoutItem *lay ) { QLayoutIterator it = lay->iterator(); <a href="qlayoutitem.html">QLayoutItem</a> *child; while ( (child = it.<a href="#current">current</a>()) != 0 ) { paintLayout( p, child ); ++it; } p-><a href="qpainter.html#drawRect">drawRect</a>( lay->geometry() ); } void ExampleWidget::paintEvent( <a href="qpaintevent.html">QPaintEvent</a> * ) { <a href="qpainter.html">QPainter</a> p( this ); if ( layout() ) paintLayout( &p, layout() ); } </pre> <p> All the functionality of QLayoutIterator is implemented by subclasses of <a href="qglayoutiterator.html">QGLayoutIterator</a>. QLayoutIterator itself is not designed to be subclassed. <p>See also <a href="appearance.html">Widget Appearance and Style</a> and <a href="geomanagement.html">Layout Management</a>. <hr><h2>Member Function Documentation</h2> <h3 class=fn><a name="QLayoutIterator"></a>QLayoutIterator::QLayoutIterator ( <a href="qglayoutiterator.html">QGLayoutIterator</a> * gi ) </h3> <p> Constructs an iterator based on <em>gi</em>. The constructed iterator takes ownership of <em>gi</em> and will delete it. <p> This constructor is provided for layout implementors. Application programmers should use <a href="qlayoutitem.html#iterator">QLayoutItem::iterator</a>() to create an iterator over a layout. <h3 class=fn><a name="QLayoutIterator-2"></a>QLayoutIterator::QLayoutIterator ( const <a href="qlayoutiterator.html">QLayoutIterator</a> & i ) </h3> <p> Creates a <a href="shclass.html#shallow-copy">shallow copy</a> of <em>i</em>, i.e. if the copy is modified, then the original will also be modified. <h3 class=fn><a name="~QLayoutIterator"></a>QLayoutIterator::~QLayoutIterator () </h3> <p> Destroys the iterator. <h3 class=fn><a href="qlayoutitem.html">QLayoutItem</a> * <a name="current"></a>QLayoutIterator::current () </h3> <p> Returns the current item, or 0 if there is no current item. <h3 class=fn>void <a name="deleteCurrent"></a>QLayoutIterator::deleteCurrent () </h3> <p> Removes and deletes the current child item from the layout and moves the iterator to the next item. This iterator will still be valid, but any other iterator over the same layout may become invalid. <h3 class=fn><a href="qlayoutitem.html">QLayoutItem</a> * <a name="operator++"></a>QLayoutIterator::operator++ () </h3> <p> Moves the iterator to the next child item and returns that item, or 0 if there is no such item. <h3 class=fn><a href="qlayoutiterator.html">QLayoutIterator</a> & <a name="operator-eq"></a>QLayoutIterator::operator= ( const <a href="qlayoutiterator.html">QLayoutIterator</a> & i ) </h3> <p> Assigns <em>i</em> to this iterator and returns a reference to this iterator. <h3 class=fn><a href="qlayoutitem.html">QLayoutItem</a> * <a name="takeCurrent"></a>QLayoutIterator::takeCurrent () </h3> <p> Removes the current child item from the layout without deleting it, and moves the iterator to the next item. Returns the removed item, or 0 if there was no item to be removed. This iterator will still be valid, but any other iterator over the same layout may become invalid. <!-- eof --> <hr><p> This file is part of the <a href="index.html">Qt toolkit</a>. Copyright © 1995-2007 <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 © 2007 <a href="troll.html">Trolltech</a><td align=center><a href="trademarks.html">Trademarks</a> <td align=right><div align=right>Qt 3.3.8</div> </table></div></address></body> </html>