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(Within character classes, the backslash is not necessary in front of certain
characters, e.g. <tt>|</tt>, but it doesn't hurt.)
<p> Wildcard patterns need no conversion.  Here are two examples:
<pre>
    <a href="qregexp.html">QRegExp</a> wild( "(*.*)" );
    wild.<a href="qregexp.html#setWildcard">setWildcard</a>( TRUE );
</pre>
 
<pre>
    // TRUE as third argument means wildcard
    <a href="qregexp.html">QRegExp</a> wild( "(*.*)", FALSE, TRUE );
</pre>
 
However, when they are used, make sure to use <a href="qregexp.html#exactMatch">QRegExp::exactMatch</a>()
rather than the obsolete <a href="qregexp.html#match">QRegExp::match</a>(). QRegExp::match(), like
QRegExp::find(), tries to find a match somewhere in the target
string, while QRegExp::exactMatch() tries to match the whole target
string.
<p> <h3> <a href="qregexp.html#operator-eq">QRegExp::operator=</a>()
</h3>
<a name="14-2"></a><p> This function has been replaced by <a href="qregexp.html#setPattern">QRegExp::setPattern</a>() in Qt 2.2.
Old code such as
<pre>
    <a href="qregexp.html">QRegExp</a> rx( "alpha" );
    rx.<a href="qregexp.html#setCaseSensitive">setCaseSensitive</a>( FALSE );
    rx.<a href="qregexp.html#setWildcard">setWildcard</a>( TRUE );
    rx = "beta";
</pre>
 
still compiles with Qt 3, but produces a different result (the case sensitivity
and wildcard options are forgotten). This way,
<pre>
    rx = "beta";
</pre>
 
is the same as
<pre>
    rx = QRegExp( "beta" );
</pre>
 
which is what one expects.
<p> <h3> QRegExp::match()
</h3>
<a name="14-3"></a><p> The following function is now obsolete, as it has an unwieldy
parameter list and was poorly named:
<ul>
<li> bool <a href="qregexp.html#match">QRegExp::match</a>( const <a href="qstring.html">QString</a> &amp; str, int index = 0,
int * len = 0, bool indexIsStart = TRUE ) const
</ul>
It will be removed in a future version of Qt. Its <a href="qregexp.html#match">documentation</a> explains how to replace it.
<p> <h3> QRegExp::find()
</h3>
<a name="14-4"></a><p> This function was removed, after a brief appearance in Qt 2.2.  Its
name clashed with <a href="qstring.html#find">QString::find</a>().  Use <a href="qregexp.html#search">QRegExp::search</a>() or <a href="qstring.html#find">QString::find</a>() instead.
<p> <h3> <a href="qstring.html#findRev">QString::findRev</a>() and <a href="qstring.html#contains">QString::contains</a>()
</h3>
<a name="14-5"></a><p> <a href="qstring.html#findRev">QString::findRev</a>()'s and <a href="qstring.html#contains">QString::contains</a>()'s semantics have changed
between 2.0 and 3.0 to be more consistent with the other overloads.
<p> For example,
<pre>
    QString( "" ).contains( QRegExp("") )
</pre>
 
returns 1 in Qt 2.0; it returns 0 in Qt 3.0. Also, "^" now really means
start of input, so
<pre>
    QString( "Heisan Hoppsan" ).contains( QRegExp("^.*$") )
</pre>
 
returns 1, not 13 or 14.
<p> This change affect very few existing programs.
<p> <h3> <a href="qstring.html#replace">QString::replace</a>()
</h3>
<a name="14-6"></a><p> With Qt 1.0 and 2.0, a <a href="qstring.html">QString</a> is converted implicitly into a <a href="qregexp.html">QRegExp</a>
as the first argument to QString::replace():
<pre>
    <a href="qstring.html">QString</a> text = fetch_it_from_somewhere();
    text.<a href="qstring.html#replace">replace</a>( QString("[A-Z]+"), "" );
</pre>
 
With Qt 3.0, the compiler gives an error. The solution is to use a
QRegExp cast:
<pre>
    text.replace( QRegExp("[A-Z]+"), "" );
</pre>
 
This change makes it possible to introduce a
QString::replace(QString, QString) overload in a future version of Qt
without breaking source compatibility.
<p> <h2> QSemiModal 
</h2>
<a name="15"></a><p> The QSemiModal class is now obsolete. You should call show() on a
modal dialog instead.
<p> <h2> QSortedList
</h2>
<a name="16"></a><p> The QSortedList class is now obsolete. Consider using a <a href="qdict.html">QDict</a>, a <a href="qmap.html">QMap</a>
or a plain <a href="qptrlist.html">QPtrList</a> instead.
<p> <h2> QTableView
</h2>
<a name="17"></a><p> The QTableView class has been obsoleted and is no longer a part of the
Qt API. Either use the powerful <a href="qtable.html">QTable</a> class or the simplistic
<a href="qgridview.html">QGridView</a> in any new code you create. If you really need the old table
view for compatibility you can find it in <tt>$QTDIR/src/attic/qttableview.{cpp,h}</tt>. Note that the class has been
renamed from QTableView to QtTableView to avoid name clashes. To use
it, simply include it in your project and rename QTableView to
QtTableView throughout.
<p> <h2> <a href="qtoolbutton.html">QToolButton</a>
</h2>
<a name="18"></a><p> The <a href="qtoolbutton.html">QToolButton</a> class used to distinguish between "on" and "off"
icons. In 3.0, this mechanism was moved into the <a href="qiconset.html">QIconSet</a> class
(see <a href="qiconset.html#State-enum">QIconSet::State</a>).
<p> The old <a href="qtoolbutton.html#onIconSet-prop">QToolButton::onIconSet</a> and <a href="qtoolbutton.html#offIconSet-prop">QToolButton::offIconSet</a>
properties are still provided so that old source will compile, but
their semantics have changed: they are now synonyms for <a href="qtoolbutton.html#iconSet-prop">QToolButton::iconSet</a>. If you used that distinction in Qt 2.x, you will
need to adjust your code to use the <a href="qiconset.html">QIconSet</a> On/Off mechanism.
<p> Likewise, the <em>on</em> parameter of these two functions is now ignored:
<p> <ul>
<li> void QToolButton::setIconSet ( const QIconSet &amp; set, bool on )
<li> QIconSet QToolButton::iconSet ( bool on ) const
</ul>
<p> These functions are only provided for ease of porting. New code
should use the following instead:
<p> <ul>
<li> void <a href="qtoolbutton.html#setIconSet">QToolButton::setIconSet</a>( const QIconSet &amp; set )
<li> QIconSet <a href="qtoolbutton.html#iconSet">QToolButton::iconSet</a>() const
</ul>
<p> Finally, this function is no longer virtual:
<p> <ul>
<li> void QToolButton::setIconSet( const QIconSet &amp; set, bool on )
</ul>
<p> If you have a class that inherits <a href="qtoolbutton.html">QToolButton</a> and that reimplements
QToolButton::setIconSet(), you should make the signature of the
reimplementation agree with the new <a href="qtoolbutton.html#setIconSet">QToolButton::setIconSet</a>(),
a virtual function.
<p> <h2> <a href="qtextstream.html">QTextStream</a>
</h2>
<a name="19"></a><p> The global QTextStream manipulators setw(), setfill() and setprecison()
were renamed to qSetW(), qSetFill() and qSetPrecision() to avoid conflicts
with <tt>&lt;iostream.h&gt;</tt>. If you used them, you must rename the occurrences to
the new names.
<p> <h2> <a href="qtranslator.html">QTranslator</a>
</h2>
<a name="20"></a><p> The <a href="qtranslator.html">QTranslator</a> class was extended in Qt 2.2, and these extensions
lead to a new interface.  This interface is used mainly by translation
tools (for example, <a href="linguist-manual.html">Qt
Linguist</a>).  For source compatibility, no member function was
effectively removed.  The <a href="qtranslator.html">QTranslator</a> documentation points out
which functions are obsolete.
<p> This function is no longer virtual:
<p> <ul>
<li> <a href="qstring.html">QString</a> <a href="qtranslator.html#find">QTranslator::find</a>( const char * context,
const char * sourceText ) const
</ul>
<p> If you have a class that inherits QTranslator and which reimplements
QTranslator::find(), you should reimplement <a href="qtranslator.html#findMessage">QTranslator::findMessage</a>() instead.
In fact, find() is now defined in terms of findMessage().  By doing the
conversion, you will also gain support for translator comments and for any
future extensions.
<p> <h2> <a href="qwidget.html">QWidget</a>
</h2>
<a name="21"></a><p> <a href="qwidget.html#backgroundColor">QWidget::backgroundColor</a>(), <a href="qwidget.html#setBackgroundColor">QWidget::setBackgroundColor</a>(),
<a href="qwidget.html#backgroundPixmap">QWidget::backgroundPixmap</a>() and <a href="qwidget.html#setBackgroundPixmap">QWidget::setBackgroundPixmap</a>() have
often been the source of much confusion in previous releases. Qt 3.0
addresses this by obsoleting these functions and by remplacing them
with eight new functions: <a href="qwidget.html#eraseColor">QWidget::eraseColor</a>(),
<a href="qwidget.html#setEraseColor">QWidget::setEraseColor</a>(), <a href="qwidget.html#erasePixmap">QWidget::erasePixmap</a>(),
<a href="qwidget.html#setErasePixmap">QWidget::setErasePixmap</a>(), <a href="qwidget.html#paletteBackgroundColor">QWidget::paletteBackgroundColor</a>(),
<a href="qwidget.html#setPaletteBackgroundColor">QWidget::setPaletteBackgroundColor</a>(),
<a href="qwidget.html#paletteBackgroundPixmap">QWidget::paletteBackgroundPixmap</a>() and
<a href="qwidget.html#setPaletteBackgroundPixmap">QWidget::setPaletteBackgroundPixmap</a>(). See their documentation for
details.
<p> <h2> QXml Classes
</h2>
<a name="22"></a><p> <h3> <a href="qxmlinputsource.html">QXmlInputSource</a>
</h3>
<a name="22-1"></a><p> The semantics of QXmlInputSource has changed slightly. This change
only affects code that parses the same data from the same input source
multiple times. In such cases you must call
<a href="qxmlinputsource.html#reset">QXmlInputSource::reset</a>() before the second call to
<a href="qxmlsimplereader.html#parse">QXmlSimpleReader::parse</a>().
<p> So code like
<pre>
    <a href="qxmlinputsource.html">QXmlInputSource</a> source( &amp;xmlFile );
    <a href="qxmlsimplereader.html">QXmlSimpleReader</a> reader;
    ...
    reader.<a href="qxmlsimplereader.html#parse">parse</a>( source );
    ...
    reader.<a href="qxmlsimplereader.html#parse">parse</a>( source );
</pre>
 
must be changed to
<pre>
    <a href="qxmlinputsource.html">QXmlInputSource</a> source( &amp;xmlFile );
    <a href="qxmlsimplereader.html">QXmlSimpleReader</a> reader;
    ...
    reader.<a href="qxmlsimplereader.html#parse">parse</a>( source );
    ...
    source.<a href="qxmlinputsource.html#reset">reset</a>();
    reader.<a href="qxmlsimplereader.html#parse">parse</a>( source );
</pre>
 
<p> <h3> <a href="qxmllocator.html">QXmlLocator</a>
</h3>
<a name="22-2"></a><p> Due to some internal changes, it was necessary to clean-up the semantics of
QXmlLocator: this class is now an abstract class. This shouldn't cause
any problems, since programmers usually used the QXmlLocator that was
reported by <a href="qxmlcontenthandler.html#setDocumentLocator">QXmlContentHandler::setDocumentLocator</a>(). If you used this
class in some other way, you must adjust your code to use the
QXmlLocator that is reported by the
QXmlContentHandler::setDocumentLocator() function.
<p> <h2> Asynchronous I/O Classes
</h2>
<a name="23"></a><p> QASyncIO, QDataSink, QDataSource, QIODeviceSource and QDataPump were
used internally in previous versions of Qt, but are not used anymore.
They are now obsolete.
<p> <h2> Transparent widgets
</h2>
<a name="24"></a><p> In Qt 2.x, the AutoMask property was used to obtain a
transparent-looking widget. In general, this approach is slow and
processor hungry. Qt 3.0 uses the BackgroundOrigin which provides
vastly improved performance and more flexibility in most cases. The
few classes for which the AutoMask property is still the best approach
are <a href="qcheckbox.html">QCheckBox</a>, <a href="qcombobox.html">QComboBox</a>, <a href="qpushbutton.html">QPushButton</a>, <a href="qradiobutton.html">QRadioButton</a> and <a href="qtabwidget.html">QTabWidget</a>.
<p> <h2> Bezier Curves
</h2>
<a name="25"></a><p> The function names for Bezier curves in <a href="qpainter.html">QPainter</a> and <a href="qpointarray.html">QPointArray</a> have
been corrected. They now properly reflect their cubic form instead of
a quadratic one. If you have been using either
QPainter::drawQuadBezier() or QPointArray::quadBezier() you must
replace these calls with
<ul>
<li> void <a href="qpainter.html#drawCubicBezier">QPainter::drawCubicBezier</a>( const QPointArray &amp;, int index=0 ) and
<li> QPointArray <a href="qpointarray.html#cubicBezier">QPointArray::cubicBezier</a>() const
</ul>
respectively. Neither the arguments nor the resulting curve have changed.
<p> <h2> Locale-aware String Comparisons in <a href="qiconview.html">QIconView</a>, <a href="qlistbox.html">QListBox</a>,
<a href="qlistview.html">QListView</a> and <a href="qtable.html">QTable</a>
</h2>
<a name="26"></a><p> In Qt 2.x, <a href="qstring.html">QString</a> only provided string comparisons using the Unicode
values of the characters of a string. This is efficient and reliable,
but it is not the appropriate order for most languages. For example,
French users expect '&eacute;' (e acute) to be treated essentially as
'e' and not put after 'z'.
<p> In Qt 3.0, <a href="qstring.html#localeAwareCompare">QString::localeAwareCompare</a>() implements locale aware
string comparisions on certain platforms. The classes <a href="qiconview.html">QIconView</a>, <a href="qlistbox.html">QListBox</a>, <a href="qlistview.html">QListView</a> and <a href="qtable.html">QTable</a> now use
QString::localeAwareCompare() instead of <a href="qstring.html#compare">QString::compare</a>(). If you
want to control the behaviour yourself you can always reimplement
<a href="qiconviewitem.html#compare">QIconViewItem::compare</a>(), <a href="qlistbox.html#text">QListBox::text</a>(), <a href="qlistviewitem.html#compare">QListViewItem::compare</a>()
or <a href="qtableitem.html#key">QTableItem::key</a>() as appropriate.
<p> 
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