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Breadcrumbs go here --> <li><a href="modules.html">Modules</a></li> <li>Qt3SupportLight</li> <li>Q3Signal</li> </ul> </div> <div class="toolbuttons toolblock"> <ul> <li id="smallA" class="t_button">A</li> <li id="medA" class="t_button active">A</li> <li id="bigA" class="t_button">A</li> <li id="print" class="t_button"><a href="javascript:this.print();"> <span>Print</span></a></li> </ul> </div> </div> <div class="content mainContent"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#public-functions">Public Functions</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <h1 class="title">Q3Signal Class Reference</h1> <!-- $$$Q3Signal-brief --> <p>The Q3Signal class can be used to send signals for classes that don't inherit <a href="qobject.html">QObject</a>. <a href="#details">More...</a></p> <!-- @@@Q3Signal --> <pre class="cpp"> <span class="preprocessor">#include <Q3Signal></span></pre><p><b>This class is part of the Qt 3 support library.</b> It is provided to keep old source code working. We strongly advise against using it in new code. See <a href="porting4.html#qsignal">Porting to Qt 4</a> for more information.</p> <p><b>Inherits: </b><a href="qobject.html">QObject</a>.</p> <ul> <li><a href="q3signal-members.html">List of all members, including inherited members</a></li> <li><a href="q3signal-obsolete.html">Obsolete members</a></li> </ul> <a name="public-functions"></a> <h2>Public Functions</h2> <table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="q3signal.html#Q3Signal">Q3Signal</a></b> ( QObject * <i>parent</i> = 0, const char * <i>name</i> = 0 )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="q3signal.html#dtor.Q3Signal">~Q3Signal</a></b> ()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="q3signal.html#activate">activate</a></b> ()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="q3signal.html#connect">connect</a></b> ( const QObject * <i>receiver</i>, const char * <i>member</i> )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> bool </td><td class="memItemRight bottomAlign"><b><a href="q3signal.html#disconnect">disconnect</a></b> ( const QObject * <i>receiver</i>, const char * <i>member</i> = 0 )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="q3signal.html#setValue">setValue</a></b> ( const QVariant & <i>value</i> )</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QVariant </td><td class="memItemRight bottomAlign"><b><a href="q3signal.html#value">value</a></b> () const</td></tr> </table> <ul> <li class="fn">29 public functions inherited from <a href="qobject.html#public-functions">QObject</a></li> </ul> <h3>Additional Inherited Members</h3> <ul> <li class="fn">1 property inherited from <a href="qobject.html#properties">QObject</a></li> <li class="fn">1 public slot inherited from <a href="qobject.html#public-slots">QObject</a></li> <li class="fn">1 signal inherited from <a href="qobject.html#signals">QObject</a></li> <li class="fn">7 static public members inherited from <a href="qobject.html#static-public-members">QObject</a></li> <li class="fn">8 protected functions inherited from <a href="qobject.html#protected-functions">QObject</a></li> </ul> <a name="details"></a> <!-- $$$Q3Signal-description --> <div class="descr"> <h2>Detailed Description</h2> <p>The Q3Signal class can be used to send signals for classes that don't inherit <a href="qobject.html">QObject</a>.</p> <p>If you want to send signals from a class that does not inherit <a href="qobject.html">QObject</a>, you can create an internal Q3Signal object to emit the signal. You must also provide a function that connects the signal to an outside object slot. This is how we used to implement signals in Qt 3's <a href="porting4.html#qmenudata">QMenuData</a> class, which was not a <a href="qobject.html">QObject</a>. In Qt 4, menus contain actions, which are <a href="qtwebkit-bridge.html#qobjects">QObjects</a>.</p> <p>In general, we recommend inheriting <a href="qobject.html">QObject</a> instead. <a href="qobject.html">QObject</a> provides much more functionality.</p> <p>You can set a single <a href="qvariant.html">QVariant</a> parameter for the signal with <a href="q3signal.html#setValue">setValue</a>().</p> <p>Note that <a href="qobject.html">QObject</a> is a <i>private</i> base class of Q3Signal, i.e. you cannot call any <a href="qobject.html">QObject</a> member functions from a Q3Signal object.</p> <p>Example:</p> <pre class="cpp"> <span class="preprocessor">#include <q3signal.h></span> <span class="keyword">class</span> MyClass { <span class="keyword">public</span>: MyClass(); <span class="operator">~</span>MyClass(); <span class="type">void</span> doSomething(); <span class="type">void</span> connect(<span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>receiver<span class="operator">,</span> <span class="keyword">const</span> <span class="type">char</span> <span class="operator">*</span>member); <span class="keyword">private</span>: <span class="type">Q3Signal</span> <span class="operator">*</span>sig; }; MyClass<span class="operator">::</span>MyClass() { sig <span class="operator">=</span> <span class="keyword">new</span> <span class="type">Q3Signal</span>; } MyClass<span class="operator">::</span><span class="operator">~</span>MyClass() { <span class="keyword">delete</span> sig; } <span class="type">void</span> MyClass<span class="operator">::</span>doSomething() { <span class="comment">// ... does something</span> sig<span class="operator">-</span><span class="operator">></span>activate(); <span class="comment">// emits the signal</span> } <span class="type">void</span> MyClass<span class="operator">::</span><a href="q3signal.html#connect">connect</a>(<span class="type"><a href="qobject.html">QObject</a></span> <span class="operator">*</span>receiver<span class="operator">,</span> <span class="keyword">const</span> <span class="type">char</span> <span class="operator">*</span>member) { sig<span class="operator">-</span><span class="operator">></span>connect(receiver<span class="operator">,</span> member); }</pre> </div> <!-- @@@Q3Signal --> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$Q3Signal[overload1]$$$Q3SignalQObject*constchar* --> <h3 class="fn"><a name="Q3Signal"></a>Q3Signal::<span class="name">Q3Signal</span> ( <span class="type"><a href="qobject.html">QObject</a></span> * <i>parent</i> = 0, const <span class="type">char</span> * <i>name</i> = 0 )</h3> <p>Constructs a signal object called <i>name</i>, with the parent object <i>parent</i>. These arguments are passed directly to <a href="qobject.html">QObject</a>.</p> <!-- @@@Q3Signal --> <!-- $$$~Q3Signal[overload1]$$$~Q3Signal --> <h3 class="fn"><a name="dtor.Q3Signal"></a>Q3Signal::<span class="name">~Q3Signal</span> ()</h3> <p>Destroys the signal. All connections are removed, as is the case with all <a href="qtwebkit-bridge.html#qobjects">QObjects</a>.</p> <!-- @@@~Q3Signal --> <!-- $$$activate[overload1]$$$activate --> <h3 class="fn"><a name="activate"></a><span class="type">void</span> Q3Signal::<span class="name">activate</span> ()</h3> <p>Emits the signal. If the platform supports <a href="qvariant.html">QVariant</a> and a parameter has been set with <a href="q3signal.html#setValue">setValue</a>(), this value is passed in the signal.</p> <!-- @@@activate --> <!-- $$$connect[overload1]$$$connectconstQObject*constchar* --> <h3 class="fn"><a name="connect"></a><span class="type">bool</span> Q3Signal::<span class="name">connect</span> ( const <span class="type"><a href="qobject.html">QObject</a></span> * <i>receiver</i>, const <span class="type">char</span> * <i>member</i> )</h3> <p>Connects the signal to <i>member</i> in object <i>receiver</i>. Returns true if the connection is successful.</p> <p><b>See also </b><a href="q3signal.html#disconnect">disconnect</a>() and <a href="qobject.html#connect">QObject::connect</a>().</p> <!-- @@@connect --> <!-- $$$disconnect[overload1]$$$disconnectconstQObject*constchar* --> <h3 class="fn"><a name="disconnect"></a><span class="type">bool</span> Q3Signal::<span class="name">disconnect</span> ( const <span class="type"><a href="qobject.html">QObject</a></span> * <i>receiver</i>, const <span class="type">char</span> * <i>member</i> = 0 )</h3> <p>Disonnects the signal from <i>member</i> in object <i>receiver</i>. Returns true if the connection existed and the disconnect was successful.</p> <p><b>See also </b><a href="q3signal.html#connect">connect</a>() and <a href="qobject.html#disconnect">QObject::disconnect</a>().</p> <!-- @@@disconnect --> <!-- $$$setValue[overload1]$$$setValueconstQVariant& --> <h3 class="fn"><a name="setValue"></a><span class="type">void</span> Q3Signal::<span class="name">setValue</span> ( const <span class="type"><a href="qvariant.html">QVariant</a></span> & <i>value</i> )</h3> <p>Sets the signal's parameter to <i>value</i></p> <p><b>See also </b><a href="q3signal.html#value">value</a>().</p> <!-- @@@setValue --> <!-- $$$value[overload1]$$$value --> <h3 class="fn"><a name="value"></a><span class="type"><a href="qvariant.html">QVariant</a></span> Q3Signal::<span class="name">value</span> () const</h3> <p>Returns the signal's parameter</p> <p><b>See also </b><a href="q3signal.html#setValue">setValue</a>().</p> <!-- @@@value --> </div> </div> </div> </div> <div class="ft"> <span></span> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2013 Digia Plc and/or its subsidiaries. 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