<!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:56 --> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> <title>TQLayoutItem 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>TQLayoutItem Class Reference</h1> <p>The TQLayoutItem class provides an abstract item that a TQLayout manipulates. <a href="#details">More...</a> <p><tt>#include <<a href="qlayout-h.html">qlayout.h</a>></tt> <p>Inherited by <a href="qlayout.html">TQLayout</a>, <a href="qspaceritem.html">TQSpacerItem</a>, and <a href="qwidgetitem.html">TQWidgetItem</a>. <p><a href="qlayoutitem-members.html">List of all member functions.</a> <h2>Public Members</h2> <ul> <li class=fn><a href="#TQLayoutItem"><b>TQLayoutItem</b></a> ( int alignment = 0 )</li> <li class=fn>virtual <a href="#~TQLayoutItem"><b>~TQLayoutItem</b></a> ()</li> <li class=fn>virtual TQSize <a href="#sizeHint"><b>sizeHint</b></a> () const = 0</li> <li class=fn>virtual TQSize <a href="#minimumSize"><b>minimumSize</b></a> () const = 0</li> <li class=fn>virtual TQSize <a href="#maximumSize"><b>maximumSize</b></a> () const = 0</li> <li class=fn>virtual TQSizePolicy::ExpandData <a href="#expanding"><b>expanding</b></a> () const = 0</li> <li class=fn>virtual void <a href="#setGeometry"><b>setGeometry</b></a> ( const TQRect & r ) = 0</li> <li class=fn>virtual TQRect <a href="#geometry"><b>geometry</b></a> () const = 0</li> <li class=fn>virtual bool <a href="#isEmpty"><b>isEmpty</b></a> () const = 0</li> <li class=fn>virtual bool <a href="#hasHeightForWidth"><b>hasHeightForWidth</b></a> () const</li> <li class=fn>virtual int <a href="#heightForWidth"><b>heightForWidth</b></a> ( int w ) const</li> <li class=fn>virtual void <a href="#invalidate"><b>invalidate</b></a> ()</li> <li class=fn>virtual TQWidget * <a href="#widget"><b>widget</b></a> ()</li> <li class=fn>virtual TQLayoutIterator <a href="#iterator"><b>iterator</b></a> ()</li> <li class=fn>virtual TQLayout * <a href="#layout"><b>layout</b></a> ()</li> <li class=fn>virtual TQSpacerItem * <a href="#spacerItem"><b>spacerItem</b></a> ()</li> <li class=fn>int <a href="#alignment"><b>alignment</b></a> () const</li> <li class=fn>virtual void <a href="#setAlignment"><b>setAlignment</b></a> ( int a )</li> </ul> <hr><a name="details"></a><h2>Detailed Description</h2> The TQLayoutItem class provides an abstract item that a <a href="qlayout.html">TQLayout</a> manipulates. <p> This is used by custom layouts. <p> Pure virtual functions are provided to return information about the layout, including, <a href="#sizeHint">sizeHint</a>(), <a href="#minimumSize">minimumSize</a>(), <a href="#maximumSize">maximumSize</a>() and <a href="#expanding">expanding</a>(). <p> The layout's geometry can be set and retrieved with <a href="#setGeometry">setGeometry</a>() and <a href="#geometry">geometry</a>(), and its alignment with <a href="#setAlignment">setAlignment</a>() and <a href="#alignment">alignment</a>(). <p> <a href="#isEmpty">isEmpty</a>() returns whether the layout is empty. <a href="#iterator">iterator</a>() returns an iterator for the layout's children. If the concrete item is a <a href="qwidget.html">TQWidget</a>, it can be retrieved using <a href="#widget">widget</a>(). Similarly for <a href="#layout">layout</a>() and <a href="#spacerItem">spacerItem</a>(). <p> <p>See also <a href="qlayout.html">TQLayout</a>, <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="TQLayoutItem"></a>TQLayoutItem::TQLayoutItem ( int alignment = 0 ) </h3> <p> Constructs a layout item with an <em>alignment</em> that is a bitwise OR of the <a href="qt.html#AlignmentFlags-enum">TQt::AlignmentFlags</a>. Not all subclasses support alignment. <h3 class=fn><a name="~TQLayoutItem"></a>TQLayoutItem::~TQLayoutItem ()<tt> [virtual]</tt> </h3> Destroys the TQLayoutItem. <h3 class=fn>int <a name="alignment"></a>TQLayoutItem::alignment () const </h3> <p> Returns the alignment of this item. <h3 class=fn><a href="qsizepolicy.html#ExpandData-enum">TQSizePolicy::ExpandData</a> <a name="expanding"></a>TQLayoutItem::expanding () const<tt> [pure virtual]</tt> </h3> <p> Implemented in subclasses to return the direction(s) this item "wants" to expand in (if any). <p>Reimplemented in <a href="qlayout.html#expanding">TQLayout</a>, <a href="qspaceritem.html#expanding">TQSpacerItem</a>, and <a href="qwidgetitem.html#expanding">TQWidgetItem</a>. <h3 class=fn><a href="qrect.html">TQRect</a> <a name="geometry"></a>TQLayoutItem::geometry () const<tt> [pure virtual]</tt> </h3> <p> Returns the rectangle covered by this layout item. <p>Example: <a href="customlayout-example.html#x1495">customlayout/border.cpp</a>. <h3 class=fn>bool <a name="hasHeightForWidth"></a>TQLayoutItem::hasHeightForWidth () const<tt> [virtual]</tt> </h3> Returns TRUE if this layout's preferred height depends on its width; otherwise returns FALSE. The default implementation returns FALSE. <p> Reimplement this function in layout managers that support height for width. <p> <p>See also <a href="#heightForWidth">heightForWidth</a>() and <a href="qwidget.html#heightForWidth">TQWidget::heightForWidth</a>(). <p>Examples: <a href="customlayout-example.html#x1496">customlayout/border.cpp</a> and <a href="customlayout-example.html#x1472">customlayout/flow.cpp</a>. <p>Reimplemented in <a href="qgridlayout.html#hasHeightForWidth">TQGridLayout</a> and <a href="qboxlayout.html#hasHeightForWidth">TQBoxLayout</a>. <h3 class=fn>int <a name="heightForWidth"></a>TQLayoutItem::heightForWidth ( int w ) const<tt> [virtual]</tt> </h3> Returns the preferred height for this layout item, given the width <em>w</em>. <p> The default implementation returns -1, indicating that the preferred height is independent of the width of the item. Using the function <a href="#hasHeightForWidth">hasHeightForWidth</a>() will typically be much faster than calling this function and testing for -1. <p> Reimplement this function in layout managers that support height for width. A typical implementation will look like this: <pre> int MyLayout::heightForWidth( int w ) const { if ( cache_dirty || cached_width != w ) { // not all C++ compilers support "mutable" MyLayout *that = (MyLayout*)this; int h = calculateHeightForWidth( w ); that->cached_hfw = h; return h; } return cached_hfw; } </pre> <p> Caching is strongly recommended; without it layout will take exponential time. <p> <p>See also <a href="#hasHeightForWidth">hasHeightForWidth</a>(). <p>Example: <a href="customlayout-example.html#x1473">customlayout/flow.cpp</a>. <p>Reimplemented in <a href="qgridlayout.html#heightForWidth">TQGridLayout</a> and <a href="qboxlayout.html#heightForWidth">TQBoxLayout</a>. <h3 class=fn>void <a name="invalidate"></a>TQLayoutItem::invalidate ()<tt> [virtual]</tt> </h3> Invalidates any cached information in this layout item. <p>Reimplemented in <a href="qlayout.html#invalidate">TQLayout</a>. <h3 class=fn>bool <a name="isEmpty"></a>TQLayoutItem::isEmpty () const<tt> [pure virtual]</tt> </h3> <p> Implemented in subclasses to return whether this item is empty, i.e. whether it contains any widgets. <p>Reimplemented in <a href="qlayout.html#isEmpty">TQLayout</a>, <a href="qspaceritem.html#isEmpty">TQSpacerItem</a>, and <a href="qwidgetitem.html#isEmpty">TQWidgetItem</a>. <h3 class=fn><a href="qlayoutiterator.html">TQLayoutIterator</a> <a name="iterator"></a>TQLayoutItem::iterator ()<tt> [virtual]</tt> </h3> Returns an iterator over this item's TQLayoutItem children. The default implementation returns an empty iterator. <p> Reimplement this function in subclasses that can have children. <p>Reimplemented in <a href="qlayout.html#iterator">TQLayout</a>. <h3 class=fn><a href="qlayout.html">TQLayout</a> * <a name="layout"></a>TQLayoutItem::layout ()<tt> [virtual]</tt> </h3> If this item is a <a href="qlayout.html">TQLayout</a>, it is returned as a TQLayout; otherwise 0 is returned. This function provides type-safe casting. <h3 class=fn><a href="qsize.html">TQSize</a> <a name="maximumSize"></a>TQLayoutItem::maximumSize () const<tt> [pure virtual]</tt> </h3> <p> Implemented in subclasses to return the maximum size of this item. <p>Reimplemented in <a href="qlayout.html#maximumSize">TQLayout</a>, <a href="qspaceritem.html#maximumSize">TQSpacerItem</a>, and <a href="qwidgetitem.html#maximumSize">TQWidgetItem</a>. <h3 class=fn><a href="qsize.html">TQSize</a> <a name="minimumSize"></a>TQLayoutItem::minimumSize () const<tt> [pure virtual]</tt> </h3> <p> Implemented in subclasses to return the minimum size of this item. <p>Examples: <a href="customlayout-example.html#x1497">customlayout/border.cpp</a>, <a href="customlayout-example.html#x1515">customlayout/card.cpp</a>, and <a href="customlayout-example.html#x1474">customlayout/flow.cpp</a>. <p>Reimplemented in <a href="qlayout.html#minimumSize">TQLayout</a>, <a href="qspaceritem.html#minimumSize">TQSpacerItem</a>, and <a href="qwidgetitem.html#minimumSize">TQWidgetItem</a>. <h3 class=fn>void <a name="setAlignment"></a>TQLayoutItem::setAlignment ( int a )<tt> [virtual]</tt> </h3> Sets the alignment of this item to <em>a</em>, which is a bitwise OR of the <a href="qt.html#AlignmentFlags-enum">TQt::AlignmentFlags</a>. Not all subclasses support alignment. <p>Example: <a href="tutorial2-09.html#x2644">chart/optionsform.cpp</a>. <h3 class=fn>void <a name="setGeometry"></a>TQLayoutItem::setGeometry ( const <a href="qrect.html">TQRect</a> & r )<tt> [pure virtual]</tt> </h3> <p> Implemented in subclasses to set this item's geometry to <em>r</em>. <p>Examples: <a href="customlayout-example.html#x1498">customlayout/border.cpp</a>, <a href="customlayout-example.html#x1516">customlayout/card.cpp</a>, and <a href="customlayout-example.html#x1475">customlayout/flow.cpp</a>. <p>Reimplemented in <a href="qlayout.html#setGeometry">TQLayout</a>, <a href="qspaceritem.html#setGeometry">TQSpacerItem</a>, and <a href="qwidgetitem.html#setGeometry">TQWidgetItem</a>. <h3 class=fn><a href="qsize.html">TQSize</a> <a name="sizeHint"></a>TQLayoutItem::sizeHint () const<tt> [pure virtual]</tt> </h3> <p> Implemented in subclasses to return the preferred size of this item. <p>Examples: <a href="customlayout-example.html#x1499">customlayout/border.cpp</a>, <a href="customlayout-example.html#x1517">customlayout/card.cpp</a>, and <a href="customlayout-example.html#x1476">customlayout/flow.cpp</a>. <p>Reimplemented in <a href="qspaceritem.html#sizeHint">TQSpacerItem</a>, <a href="qwidgetitem.html#sizeHint">TQWidgetItem</a>, <a href="qgridlayout.html#sizeHint">TQGridLayout</a>, and <a href="qboxlayout.html#sizeHint">TQBoxLayout</a>. <h3 class=fn><a href="qspaceritem.html">TQSpacerItem</a> * <a name="spacerItem"></a>TQLayoutItem::spacerItem ()<tt> [virtual]</tt> </h3> If this item is a <a href="qspaceritem.html">TQSpacerItem</a>, it is returned as a TQSpacerItem; otherwise 0 is returned. This function provides type-safe casting. <h3 class=fn><a href="qwidget.html">TQWidget</a> * <a name="widget"></a>TQLayoutItem::widget ()<tt> [virtual]</tt> </h3> If this item is a <a href="qwidget.html">TQWidget</a>, it is returned as a TQWidget; otherwise 0 is returned. This function provides type-safe casting. <p>Reimplemented in <a href="qwidgetitem.html#widget">TQWidgetItem</a>. <!-- eof --> <hr><p> This file is part of the <a href="index.html">TQt 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>TQt 3.3.8</div> </table></div></address></body> </html>