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diff --git a/doc/html/qobject.html b/doc/html/qobject.html new file mode 100644 index 0000000..8579f78 --- /dev/null +++ b/doc/html/qobject.html @@ -0,0 +1,958 @@ +<!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/qobject.cpp:105 --> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1"> +<title>QObject 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>QObject Class Reference</h1> + +<p>The QObject class is the base class of all Qt objects. +<a href="#details">More...</a> +<p>All the functions in this class are <a href="threads.html#reentrant">reentrant</a> when Qt is built with thread support.</p> +<p><tt>#include <<a href="qobject-h.html">qobject.h</a>></tt> +<p>Inherits <a href="qt.html">Qt</a>. +<p>Inherited by <a href="qaccel.html">QAccel</a>, <a href="qaccessibleobject.html">QAccessibleObject</a>, <a href="qaction.html">QAction</a>, <a href="qapplication.html">QApplication</a>, <a href="qassistantclient.html">QAssistantClient</a>, <a href="qdatapump.html">QDataPump</a>, <a href="qaxobject.html">QAxObject</a>, <a href="qaxscript.html">QAxScript</a>, <a href="qaxscriptmanager.html">QAxScriptManager</a>, <a href="qwidget.html">QWidget</a>, <a href="qcanvas.html">QCanvas</a>, <a href="qstyle.html">QStyle</a>, <a href="qclipboard.html">QClipboard</a>, <a href="qcopchannel.html">QCopChannel</a>, <a href="qdns.html">QDns</a>, <a href="qlayout.html">QLayout</a>, <a href="qdragobject.html">QDragObject</a>, <a href="qeditorfactory.html">QEditorFactory</a>, <a href="qeventloop.html">QEventLoop</a>, <a href="qfileiconprovider.html">QFileIconProvider</a>, <a href="qnetworkprotocol.html">QNetworkProtocol</a>, <a href="qwskeyboardhandler.html">QWSKeyboardHandler</a>, <a href="qnetworkoperation.html">QNetworkOperation</a>, <a href="qnpinstance.html">QNPInstance</a>, <a href="qobjectcleanuphandler.html">QObjectCleanupHandler</a>, <a href="qprocess.html">QProcess</a>, <a href="qserversocket.html">QServerSocket</a>, <a href="qsessionmanager.html">QSessionManager</a>, <a href="qsignal.html">QSignal</a>, <a href="qsignalmapper.html">QSignalMapper</a>, <a href="qsocket.html">QSocket</a>, <a href="qsocketnotifier.html">QSocketNotifier</a>, <a href="qsound.html">QSound</a>, <a href="qsqldatabase.html">QSqlDatabase</a>, <a href="qsqldriver.html">QSqlDriver</a>, <a href="qsqlform.html">QSqlForm</a>, <a href="qstylesheet.html">QStyleSheet</a>, <a href="qtimer.html">QTimer</a>, <a href="qtooltipgroup.html">QToolTipGroup</a>, <a href="qtranslator.html">QTranslator</a>, <a href="qurloperator.html">QUrlOperator</a>, and <a href="qvalidator.html">QValidator</a>. +<p><a href="qobject-members.html">List of all member functions.</a> +<h2>Public Members</h2> +<ul> +<li class=fn><a href="#QObject"><b>QObject</b></a> ( QObject * parent = 0, const char * name = 0 )</li> +<li class=fn>virtual <a href="#~QObject"><b>~QObject</b></a> ()</li> +<li class=fn>virtual const char * <a href="#className"><b>className</b></a> () const</li> +<li class=fn>virtual QMetaObject * <a href="#metaObject"><b>metaObject</b></a> () const</li> +<li class=fn>virtual bool <a href="#event"><b>event</b></a> ( QEvent * e )</li> +<li class=fn>virtual bool <a href="#eventFilter"><b>eventFilter</b></a> ( QObject * watched, QEvent * e )</li> +<li class=fn>bool <a href="#isA"><b>isA</b></a> ( const char * clname ) const</li> +<li class=fn>bool <a href="#inherits"><b>inherits</b></a> ( const char * clname ) const</li> +<li class=fn>const char * <a href="#name"><b>name</b></a> () const</li> +<li class=fn>const char * <a href="#name-2"><b>name</b></a> ( const char * defaultName ) const</li> +<li class=fn>virtual void <a href="#setName"><b>setName</b></a> ( const char * name )</li> +<li class=fn>bool <a href="#isWidgetType"><b>isWidgetType</b></a> () const</li> +<li class=fn>bool <a href="#highPriority"><b>highPriority</b></a> () const</li> +<li class=fn>bool <a href="#signalsBlocked"><b>signalsBlocked</b></a> () const</li> +<li class=fn>void <a href="#blockSignals"><b>blockSignals</b></a> ( bool block )</li> +<li class=fn>int <a href="#startTimer"><b>startTimer</b></a> ( int interval )</li> +<li class=fn>void <a href="#killTimer"><b>killTimer</b></a> ( int id )</li> +<li class=fn>void <a href="#killTimers"><b>killTimers</b></a> ()</li> +<li class=fn>QObject * <a href="#child"><b>child</b></a> ( const char * objName, const char * inheritsClass = 0, bool recursiveSearch = TRUE )</li> +<li class=fn>const QObjectList * <a href="#children"><b>children</b></a> () const</li> +<li class=fn>QObjectList * <a href="#queryList"><b>queryList</b></a> ( const char * inheritsClass = 0, const char * objName = 0, bool regexpMatch = TRUE, bool recursiveSearch = TRUE ) const</li> +<li class=fn>virtual void <a href="#insertChild"><b>insertChild</b></a> ( QObject * obj )</li> +<li class=fn>virtual void <a href="#removeChild"><b>removeChild</b></a> ( QObject * obj )</li> +<li class=fn>void <a href="#installEventFilter"><b>installEventFilter</b></a> ( const QObject * filterObj )</li> +<li class=fn>void <a href="#removeEventFilter"><b>removeEventFilter</b></a> ( const QObject * obj )</li> +<li class=fn>bool <a href="#connect-2"><b>connect</b></a> ( const QObject * sender, const char * signal, const char * member ) const</li> +<li class=fn>bool <a href="#disconnect-2"><b>disconnect</b></a> ( const char * signal = 0, const QObject * receiver = 0, const char * member = 0 )</li> +<li class=fn>bool <a href="#disconnect-3"><b>disconnect</b></a> ( const QObject * receiver, const char * member = 0 )</li> +<li class=fn>void <a href="#dumpObjectTree"><b>dumpObjectTree</b></a> ()</li> +<li class=fn>void <a href="#dumpObjectInfo"><b>dumpObjectInfo</b></a> ()</li> +<li class=fn>virtual bool <a href="#setProperty"><b>setProperty</b></a> ( const char * name, const QVariant & value )</li> +<li class=fn>virtual QVariant <a href="#property"><b>property</b></a> ( const char * name ) const</li> +<li class=fn>QObject * <a href="#parent"><b>parent</b></a> () const</li> +</ul> +<h2>Public Slots</h2> +<ul> +<li class=fn>void <a href="#deleteLater"><b>deleteLater</b></a> ()</li> +</ul> +<h2>Signals</h2> +<ul> +<li class=fn>void <a href="#destroyed"><b>destroyed</b></a> ()</li> +<li class=fn>void <a href="#destroyed-2"><b>destroyed</b></a> ( QObject * obj )</li> +</ul> +<h2>Static Public Members</h2> +<ul> +<li class=fn>QString <a href="#tr"><b>tr</b></a> ( const char * sourceText, const char * comment )</li> +<li class=fn>QString <a href="#trUtf8"><b>trUtf8</b></a> ( const char * sourceText, const char * comment )</li> +<li class=fn>const QObjectList * <a href="#objectTrees"><b>objectTrees</b></a> ()</li> +<li class=fn>bool <a href="#connect"><b>connect</b></a> ( const QObject * sender, const char * signal, const QObject * receiver, const char * member )</li> +<li class=fn>bool <a href="#disconnect"><b>disconnect</b></a> ( const QObject * sender, const char * signal, const QObject * receiver, const char * member )</li> +</ul> +<h2>Properties</h2> +<ul> +<li class=fn>QCString <a href="#name-prop"><b>name</b></a> - the name of this object</li> +</ul> +<h2>Protected Members</h2> +<ul> +<li class=fn>const QObject * <a href="#sender"><b>sender</b></a> ()</li> +<li class=fn>virtual void <a href="#timerEvent"><b>timerEvent</b></a> ( QTimerEvent * )</li> +<li class=fn>virtual void <a href="#childEvent"><b>childEvent</b></a> ( QChildEvent * )</li> +<li class=fn>virtual void <a href="#customEvent"><b>customEvent</b></a> ( QCustomEvent * )</li> +<li class=fn>virtual void <a href="#connectNotify"><b>connectNotify</b></a> ( const char * signal )</li> +<li class=fn>virtual void <a href="#disconnectNotify"><b>disconnectNotify</b></a> ( const char * signal )</li> +<li class=fn>virtual bool <a href="#checkConnectArgs"><b>checkConnectArgs</b></a> ( const char * signal, const QObject * receiver, const char * member )</li> +</ul> +<h2>Static Protected Members</h2> +<ul> +<li class=fn>QCString <a href="#normalizeSignalSlot"><b>normalizeSignalSlot</b></a> ( const char * signalSlot )</li> +</ul> +<h2>Related Functions</h2> +<ul> +<li class=fn>void * <a href="#qt_find_obj_child"><b>qt_find_obj_child</b></a> ( QObject * parent, const char * type, const char * name )</li> +</ul> +<hr><a name="details"></a><h2>Detailed Description</h2> + + +The QObject class is the base class of all Qt objects. +<p> + + +<p> QObject is the heart of the <a href="object.html">Qt object model.</a> The central feature in this model is a very powerful +mechanism for seamless object communication called <a href="signalsandslots.html">signals and slots</a>. You can +connect a signal to a slot with <a href="#connect">connect</a>() and destroy the +connection with <a href="#disconnect">disconnect</a>(). To avoid never ending notification +loops you can temporarily block signals with <a href="#blockSignals">blockSignals</a>(). The +protected functions <a href="#connectNotify">connectNotify</a>() and <a href="#disconnectNotify">disconnectNotify</a>() make it +possible to track connections. +<p> QObjects organize themselves in object trees. When you create a +QObject with another object as parent, the object will +automatically do an <a href="#insertChild">insertChild</a>() on the parent and thus show up +in the parent's <a href="#children">children</a>() list. The parent takes ownership of the +object i.e. it will automatically delete its children in its +destructor. You can look for an object by name and optionally type +using <a href="#child">child</a>() or <a href="#queryList">queryList</a>(), and get the list of tree roots using +<a href="#objectTrees">objectTrees</a>(). +<p> Every object has an object <a href="#name">name</a>() and can report its <a href="#className">className</a>() +and whether it <a href="#inherits">inherits</a>() another class in the QObject inheritance +hierarchy. +<p> When an object is deleted, it emits a <a href="#destroyed">destroyed</a>() signal. You can +catch this signal to avoid dangling references to QObjects. The +<a href="qguardedptr.html">QGuardedPtr</a> class provides an elegant way to use this feature. +<p> QObjects can receive events through <a href="#event">event</a>() and filter the events +of other objects. See <a href="#installEventFilter">installEventFilter</a>() and <a href="#eventFilter">eventFilter</a>() for +details. A convenience handler, <a href="#childEvent">childEvent</a>(), can be reimplemented +to catch child events. +<p> Last but not least, QObject provides the basic timer support in +Qt; see <a href="qtimer.html">QTimer</a> for high-level support for timers. +<p> Notice that the <a href="metaobjects.html#Q_OBJECT">Q_OBJECT</a> macro is mandatory for any object that +implements signals, slots or properties. You also need to run the +<a href="moc.html">moc program (Meta Object Compiler)</a> on the +source file. We strongly recommend the use of this macro in <em>all</em> +subclasses of QObject regardless of whether or not they actually +use signals, slots and properties, since failure to do so may lead +certain functions to exhibit undefined behaviour. +<p> All Qt widgets inherit QObject. The convenience function +<a href="#isWidgetType">isWidgetType</a>() returns whether an object is actually a widget. It +is much faster than <a href="#inherits">inherits</a>( "QWidget" ). +<p> Some QObject functions, e.g. <a href="#children">children</a>(), <a href="#objectTrees">objectTrees</a>() and +<a href="#queryList">queryList</a>() return a <a href="qobjectlist.html">QObjectList</a>. A QObjectList is a <a href="qptrlist.html">QPtrList</a> of +QObjects. QObjectLists support the same operations as QPtrLists +and have an iterator class, QObjectListIt. +<p>See also <a href="objectmodel.html">Object Model</a>. + +<hr><h2>Member Function Documentation</h2> +<h3 class=fn><a name="QObject"></a>QObject::QObject ( <a href="qobject.html">QObject</a> * parent = 0, const char * name = 0 ) +</h3> +Constructs an object called <em>name</em> with parent object, <em>parent</em>. +<p> The parent of an object may be viewed as the object's owner. For +instance, a <a href="qdialog.html">dialog box</a> is the parent of the +"OK" and "Cancel" buttons it contains. +<p> The destructor of a parent object destroys all child objects. +<p> Setting <em>parent</em> to 0 constructs an object with no parent. If the +object is a widget, it will become a top-level window. +<p> The object name is some text that can be used to identify a +QObject. It's particularly useful in conjunction with <a href="designer-manual.html"><i>Qt Designer</i></a>. You can find an +object by name (and type) using <a href="#child">child</a>(). To find several objects +use <a href="#queryList">queryList</a>(). +<p> <p>See also <a href="#parent">parent</a>(), <a href="#name-prop">name</a>, <a href="#child">child</a>(), and <a href="#queryList">queryList</a>(). + +<h3 class=fn><a name="~QObject"></a>QObject::~QObject ()<tt> [virtual]</tt> +</h3> +Destroys the object, deleting all its child objects. +<p> All signals to and from the object are automatically disconnected. +<p> <b>Warning:</b> All child objects are deleted. If any of these objects +are on the stack or global, sooner or later your program will +crash. We do not recommend holding pointers to child objects from +outside the parent. If you still do, the <a href="#destroyed">QObject::destroyed</a>() +signal gives you an opportunity to detect when an object is +destroyed. +<p> <b>Warning:</b> Deleting a QObject while pending events are waiting to be +delivered can cause a crash. You must not delete the QObject +directly from a thread that is not the GUI thread. Use the +<a href="#deleteLater">QObject::deleteLater</a>() method instead, which will cause the event +loop to delete the object after all pending events have been +delivered to the object. + +<h3 class=fn>void <a name="blockSignals"></a>QObject::blockSignals ( bool block ) +</h3> +Blocks signals if <em>block</em> is TRUE, or unblocks signals if <em>block</em> is FALSE. +<p> Emitted signals disappear into hyperspace if signals are blocked. +Note that the <a href="#destroyed">destroyed</a>() signals will be emitted even if the signals +for this object have been blocked. + +<p>Examples: <a href="rot-example.html#x1371">rot13/rot13.cpp</a> and <a href="qaxserver-example-simple.html#x2525">simple/main.cpp</a>. +<h3 class=fn>bool <a name="checkConnectArgs"></a>QObject::checkConnectArgs ( const char * signal, const <a href="qobject.html">QObject</a> * receiver, const char * member )<tt> [virtual protected]</tt> +</h3> + +<p> Returns TRUE if the <em>signal</em> and the <em>member</em> arguments are +compatible; otherwise returns FALSE. (The <em>receiver</em> argument is +currently ignored.) +<p> <b>Warning:</b> We recommend that you use the default implementation and +do not reimplement this function. +<p> + +<h3 class=fn><a href="qobject.html">QObject</a> * <a name="child"></a>QObject::child ( const char * objName, const char * inheritsClass = 0, bool recursiveSearch = TRUE ) +</h3> +Searches the children and optionally grandchildren of this object, +and returns a child that is called <em>objName</em> that inherits <em>inheritsClass</em>. If <em>inheritsClass</em> is 0 (the default), any class +matches. +<p> If <em>recursiveSearch</em> is TRUE (the default), <a href="#child">child</a>() performs a +depth-first search of the object's children. +<p> If there is no such object, this function returns 0. If there are +more than one, the first one found is retured; if you need all of +them, use <a href="#queryList">queryList</a>(). + +<h3 class=fn>void <a name="childEvent"></a>QObject::childEvent ( <a href="qchildevent.html">QChildEvent</a> * )<tt> [virtual protected]</tt> +</h3> +This event handler can be reimplemented in a subclass to receive +child events. +<p> Child events are sent to objects when children are inserted or +removed. +<p> Note that events with <a href="qevent.html#type">QEvent::type</a>() <a href="qevent.html#Type-enum">QEvent::ChildInserted</a> are +posted (with <a href="qapplication.html#postEvent">QApplication::postEvent</a>()) to make sure that the +child's construction is completed before this function is called. +<p> If a child is removed immediately after it is inserted, the <tt>ChildInserted</tt> event may be suppressed, but the <tt>ChildRemoved</tt> +event will always be sent. In such cases it is possible that there +will be a <tt>ChildRemoved</tt> event without a corresponding <tt>ChildInserted</tt> event. +<p> If you change state based on <tt>ChildInserted</tt> events, call +<a href="qwidget.html#constPolish">QWidget::constPolish</a>(), or do +<pre> + QApplication::<a href="qapplication.html#sendPostedEvents">sendPostedEvents</a>( this, QEvent::ChildInserted ); + </pre> + +in functions that depend on the state. One notable example is +<a href="qwidget.html#sizeHint">QWidget::sizeHint</a>(). +<p> <p>See also <a href="#event">event</a>() and <a href="qchildevent.html">QChildEvent</a>. + +<p>Reimplemented in <a href="qmainwindow.html#childEvent">QMainWindow</a> and <a href="qsplitter.html#childEvent">QSplitter</a>. +<h3 class=fn>const <a href="qobjectlist.html">QObjectList</a> * <a name="children"></a>QObject::children () const +</h3> + +<p> Returns a list of child objects, or 0 if this object has no +children. +<p> The <a href="qobjectlist.html">QObjectList</a> class is defined in the <a href="qobjectlist-h.html">qobjectlist.h</a> header +file. +<p> The first child added is the <a href="qptrlist.html#first">first</a> +object in the list and the last child added is the <a href="qptrlist.html#last">last</a> object in the list, i.e. new +children are appended at the end. +<p> Note that the list order changes when <a href="qwidget.html">QWidget</a> children are <a href="qwidget.html#raise">raised</a> or <a href="qwidget.html#lower">lowered.</a> A widget that is raised becomes the last object +in the list, and a widget that is lowered becomes the first object +in the list. +<p> <p>See also <a href="#child">child</a>(), <a href="#queryList">queryList</a>(), <a href="#parent">parent</a>(), <a href="#insertChild">insertChild</a>(), and <a href="#removeChild">removeChild</a>(). + +<h3 class=fn>const char * <a name="className"></a>QObject::className () const<tt> [virtual]</tt> +</h3> + +<p> Returns the class name of this object. +<p> This function is generated by the <a href="metaobjects.html">Meta + Object Compiler.</a> +<p> <b>Warning:</b> This function will return the wrong name if the class +definition lacks the <a href="metaobjects.html#Q_OBJECT">Q_OBJECT</a> macro. +<p> <p>See also <a href="#name-prop">name</a>, <a href="#inherits">inherits</a>(), <a href="#isA">isA</a>(), and <a href="#isWidgetType">isWidgetType</a>(). + +<p>Example: <a href="sql.html#x2235">sql/overview/custom1/main.cpp</a>. +<h3 class=fn>bool <a name="connect"></a>QObject::connect ( const <a href="qobject.html">QObject</a> * sender, const char * signal, const <a href="qobject.html">QObject</a> * receiver, const char * member )<tt> [static]</tt> +</h3> +Connects <em>signal</em> from the <em>sender</em> object to <em>member</em> in object +<em>receiver</em>, and returns TRUE if the connection succeeds; otherwise +returns FALSE. +<p> You must use the SIGNAL() and SLOT() macros when specifying the <em>signal</em> +and the <em>member</em>, for example: +<pre> + <a href="qlabel.html">QLabel</a> *label = new <a href="qlabel.html">QLabel</a>; + <a href="qscrollbar.html">QScrollBar</a> *scroll = new <a href="qscrollbar.html">QScrollBar</a>; + QObject::<a href="#connect">connect</a>( scroll, SIGNAL(<a href="qscrollbar.html#valueChanged">valueChanged</a>(int)), + label, SLOT(<a href="qlabel.html#setNum">setNum</a>(int)) ); + </pre> + +<p> This example ensures that the label always displays the current +scroll bar value. Note that the signal and slots parameters must not +contain any variable names, only the type. E.g. the following would +not work and return FALSE: +<a href="#connect">QObject::connect</a>( scroll, SIGNAL(valueChanged(int v)), +label, SLOT(setNum(int v)) ); +<p> A signal can also be connected to another signal: +<p> <pre> + class MyWidget : public <a href="qwidget.html">QWidget</a> + { + <a href="metaobjects.html#Q_OBJECT">Q_OBJECT</a> + public: + MyWidget(); + + signals: + void myUsefulSignal(); + + private: + <a href="qpushbutton.html">QPushButton</a> *aButton; + }; + + MyWidget::MyWidget() + { + aButton = new <a href="qpushbutton.html">QPushButton</a>( this ); + <a href="#connect">connect</a>( aButton, SIGNAL(<a href="qbutton.html#clicked">clicked</a>()), SIGNAL(myUsefulSignal()) ); + } + </pre> + +<p> In this example, the MyWidget constructor relays a signal from a +private member variable, and makes it available under a name that +relates to MyWidget. +<p> A signal can be connected to many slots and signals. Many signals +can be connected to one slot. +<p> If a signal is connected to several slots, the slots are activated +in an arbitrary order when the signal is emitted. +<p> The function returns TRUE if it successfully connects the signal +to the slot. It will return FALSE if it cannot create the +connection, for example, if QObject is unable to verify the +existence of either <em>signal</em> or <em>member</em>, or if their signatures +aren't compatible. +<p> A signal is emitted for <em>every</em> connection you make, so if you +duplicate a connection, two signals will be emitted. You can +always break a connection using <a href="#disconnect">disconnect</a>(). +<p> <p>See also <a href="#disconnect">disconnect</a>(). + +<p>Examples: <a href="qaction-application-example.html#x1179">action/main.cpp</a>, <a href="simple-application-example.html#x1599">application/main.cpp</a>, <a href="extension-dialog-example.html#x2868">extension/main.cpp</a>, <a href="iconview-example.html#x1460">iconview/main.cpp</a>, <a href="archivesearch-example.html#x489">network/archivesearch/main.cpp</a>, <a href="regexptester-example.html#x2512">regexptester/main.cpp</a>, and <a href="tutorial1-02.html#x2291">t2/main.cpp</a>. +<h3 class=fn>bool <a name="connect-2"></a>QObject::connect ( const <a href="qobject.html">QObject</a> * sender, const char * signal, const char * member ) const +</h3> +This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +<p> Connects <em>signal</em> from the <em>sender</em> object to this object's <em>member</em>. +<p> Equivalent to: <tt>QObject::connect(sender, signal, this, member)</tt>. +<p> <p>See also <a href="#disconnect">disconnect</a>(). + +<h3 class=fn>void <a name="connectNotify"></a>QObject::connectNotify ( const char * signal )<tt> [virtual protected]</tt> +</h3> + +<p> This virtual function is called when something has been connected +to <em>signal</em> in this object. +<p> <b>Warning:</b> This function violates the object-oriented principle of +modularity. However, it might be useful when you need to perform +expensive initialization only if something is connected to a +signal. +<p> <p>See also <a href="#connect">connect</a>() and <a href="#disconnectNotify">disconnectNotify</a>(). + +<h3 class=fn>void <a name="customEvent"></a>QObject::customEvent ( <a href="qcustomevent.html">QCustomEvent</a> * )<tt> [virtual protected]</tt> +</h3> +This event handler can be reimplemented in a subclass to receive +custom events. Custom events are user-defined events with a type +value at least as large as the "User" item of the <a href="qevent.html#Type-enum">QEvent::Type</a> +enum, and is typically a <a href="qcustomevent.html">QCustomEvent</a> or QCustomEvent subclass. +<p> <p>See also <a href="#event">event</a>() and <a href="qcustomevent.html">QCustomEvent</a>. + +<h3 class=fn>void <a name="deleteLater"></a>QObject::deleteLater ()<tt> [slot]</tt> +</h3> +Performs a deferred deletion of this object. +<p> Instead of an immediate deletion this function schedules a +deferred delete event for processing when Qt returns to the main +event loop. + +<p>Example: <a href="bigtable-example.html#x1290">table/bigtable/main.cpp</a>. +<h3 class=fn>void <a name="destroyed"></a>QObject::destroyed ()<tt> [signal]</tt> +</h3> + +<p> This signal is emitted when the object is being destroyed. +<p> Note that the signal is emitted by the QObject destructor, so +the object's virtual table is already degenerated at this point, +and it is not safe to call any functions on the object emitting +the signal. This signal can not be blocked. +<p> All the objects's children are destroyed immediately after this +signal is emitted. + +<h3 class=fn>void <a name="destroyed-2"></a>QObject::destroyed ( <a href="qobject.html">QObject</a> * obj )<tt> [signal]</tt> +</h3> +This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +<p> This signal is emitted immediately before the object <em>obj</em> is +destroyed, and can not be blocked. +<p> All the objects's children are destroyed immediately after this +signal is emitted. + +<h3 class=fn>bool <a name="disconnect"></a>QObject::disconnect ( const <a href="qobject.html">QObject</a> * sender, const char * signal, const <a href="qobject.html">QObject</a> * receiver, const char * member )<tt> [static]</tt> +</h3> +Disconnects <em>signal</em> in object <em>sender</em> from <em>member</em> in object +<em>receiver</em>. +<p> A signal-slot connection is removed when either of the objects +involved are destroyed. +<p> <a href="#disconnect">disconnect</a>() is typically used in three ways, as the following +examples demonstrate. +<ol type=1> +<li> Disconnect everything connected to an object's signals: +<pre> + <a href="#disconnect">disconnect</a>( myObject, 0, 0, 0 ); + </pre> + +equivalent to the non-static overloaded function +<pre> + myObject->disconnect(); + </pre> + +<li> Disconnect everything connected to a specific signal: +<pre> + <a href="#disconnect">disconnect</a>( myObject, SIGNAL(mySignal()), 0, 0 ); + </pre> + +equivalent to the non-static overloaded function +<pre> + myObject->disconnect( SIGNAL(mySignal()) ); + </pre> + +<li> Disconnect a specific receiver: +<pre> + <a href="#disconnect">disconnect</a>( myObject, 0, myReceiver, 0 ); + </pre> + +equivalent to the non-static overloaded function +<pre> + myObject->disconnect( myReceiver ); + </pre> + +</ol> +<p> 0 may be used as a wildcard, meaning "any signal", "any receiving +object", or "any slot in the receiving object", respectively. +<p> The <em>sender</em> may never be 0. (You cannot disconnect signals from +more than one object in a single call.) +<p> If <em>signal</em> is 0, it disconnects <em>receiver</em> and <em>member</em> from +any signal. If not, only the specified signal is disconnected. +<p> If <em>receiver</em> is 0, it disconnects anything connected to <em>signal</em>. If not, slots in objects other than <em>receiver</em> are not +disconnected. +<p> If <em>member</em> is 0, it disconnects anything that is connected to <em>receiver</em>. If not, only slots named <em>member</em> will be disconnected, +and all other slots are left alone. The <em>member</em> must be 0 if <em>receiver</em> is left out, so you cannot disconnect a +specifically-named slot on all objects. +<p> <p>See also <a href="#connect">connect</a>(). + +<h3 class=fn>bool <a name="disconnect-2"></a>QObject::disconnect ( const char * signal = 0, const <a href="qobject.html">QObject</a> * receiver = 0, const char * member = 0 ) +</h3> +This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +<p> Disconnects <em>signal</em> from <em>member</em> of <em>receiver</em>. +<p> A signal-slot connection is removed when either of the objects +involved are destroyed. + +<h3 class=fn>bool <a name="disconnect-3"></a>QObject::disconnect ( const <a href="qobject.html">QObject</a> * receiver, const char * member = 0 ) +</h3> +This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +<p> Disconnects all signals in this object from <em>receiver</em>'s <em>member</em>. +<p> A signal-slot connection is removed when either of the objects +involved are destroyed. + +<h3 class=fn>void <a name="disconnectNotify"></a>QObject::disconnectNotify ( const char * signal )<tt> [virtual protected]</tt> +</h3> + +<p> This virtual function is called when something has been +disconnected from <em>signal</em> in this object. +<p> <b>Warning:</b> This function violates the object-oriented principle of +modularity. However, it might be useful for optimizing access to +expensive resources. +<p> <p>See also <a href="#disconnect">disconnect</a>() and <a href="#connectNotify">connectNotify</a>(). + +<h3 class=fn>void <a name="dumpObjectInfo"></a>QObject::dumpObjectInfo () +</h3> +Dumps information about signal connections, etc. for this object +to the debug output. +<p> This function is useful for debugging, but does nothing if the +library has been compiled in release mode (i.e. without debugging +information). + +<h3 class=fn>void <a name="dumpObjectTree"></a>QObject::dumpObjectTree () +</h3> +Dumps a tree of children to the debug output. +<p> This function is useful for debugging, but does nothing if the +library has been compiled in release mode (i.e. without debugging +information). + +<h3 class=fn>bool <a name="event"></a>QObject::event ( <a href="qevent.html">QEvent</a> * e )<tt> [virtual]</tt> +</h3> +This virtual function receives events to an object and should +return TRUE if the event <em>e</em> was recognized and processed. +<p> The <a href="#event">event</a>() function can be reimplemented to customize the +behavior of an object. +<p> <p>See also <a href="#installEventFilter">installEventFilter</a>(), <a href="#timerEvent">timerEvent</a>(), <a href="qapplication.html#sendEvent">QApplication::sendEvent</a>(), <a href="qapplication.html#postEvent">QApplication::postEvent</a>(), and <a href="qwidget.html#event">QWidget::event</a>(). + +<p>Reimplemented in <a href="qwidget.html#event">QWidget</a>. +<h3 class=fn>bool <a name="eventFilter"></a>QObject::eventFilter ( <a href="qobject.html">QObject</a> * watched, <a href="qevent.html">QEvent</a> * e )<tt> [virtual]</tt> +</h3> +Filters events if this object has been installed as an event +filter for the <em>watched</em> object. +<p> In your reimplementation of this function, if you want to filter +the event <em>e</em>, out, i.e. stop it being handled further, return +TRUE; otherwise return FALSE. +<p> Example: +<pre> + class MyMainWindow : public <a href="qmainwindow.html">QMainWindow</a> + { + public: + MyMainWindow( <a href="qwidget.html">QWidget</a> *parent = 0, const char *name = 0 ); + + protected: + bool eventFilter( QObject *obj, QEvent *ev ); + + private: + <a href="qtextedit.html">QTextEdit</a> *textEdit; + }; + + MyMainWindow::MyMainWindow( <a href="qwidget.html">QWidget</a> *parent, const char *name ) + : <a href="qmainwindow.html">QMainWindow</a>( parent, name ) + { + textEdit = new <a href="qtextedit.html">QTextEdit</a>( this ); + <a href="qmainwindow.html#setCentralWidget">setCentralWidget</a>( textEdit ); + textEdit-><a href="#installEventFilter">installEventFilter</a>( this ); + } + + bool MyMainWindow::<a href="#eventFilter">eventFilter</a>( QObject *obj, QEvent *ev ) + { + if ( obj == textEdit ) { + if ( e->type() == QEvent::KeyPress ) { + <a href="qkeyevent.html">QKeyEvent</a> *k = (QKeyEvent*)ev; + <a href="qapplication.html#qDebug">qDebug</a>( "Ate key press %d", k-><a href="qkeyevent.html#key">key</a>() ); + return TRUE; + } else { + return FALSE; + } + } else { + // pass the event on to the parent class + return QMainWindow::eventFilter( obj, ev ); + } + } + </pre> + +<p> Notice in the example above that unhandled events are passed to +the base class's <a href="#eventFilter">eventFilter</a>() function, since the base class +might have reimplemented eventFilter() for its own internal +purposes. +<p> <b>Warning:</b> If you delete the receiver object in this function, be +sure to return TRUE. Otherwise, Qt will forward the event to the +deleted object and the program might crash. +<p> <p>See also <a href="#installEventFilter">installEventFilter</a>(). + +<p>Reimplemented in <a href="qaccel.html#eventFilter">QAccel</a>, <a href="qscrollview.html#eventFilter">QScrollView</a>, and <a href="qspinbox.html#eventFilter">QSpinBox</a>. +<h3 class=fn>bool <a name="highPriority"></a>QObject::highPriority () const +</h3> + +<p> Returns TRUE if the object is a high-priority object, or FALSE if +it is a standard-priority object. +<p> High-priority objects are placed first in QObject's list of +children on the assumption that they will be referenced very +often. + +<h3 class=fn>bool <a name="inherits"></a>QObject::inherits ( const char * clname ) const +</h3> +Returns TRUE if this object is an instance of a class that +inherits <em>clname</em>, and <em>clname</em> inherits QObject; otherwise +returns FALSE. +<p> A class is considered to inherit itself. +<p> Example: +<pre> + <a href="qtimer.html">QTimer</a> *t = new <a href="qtimer.html">QTimer</a>; // QTimer inherits QObject + t-><a href="#inherits">inherits</a>( "QTimer" ); // returns TRUE + t-><a href="#inherits">inherits</a>( "QObject" ); // returns TRUE + t-><a href="#inherits">inherits</a>( "QButton" ); // returns FALSE + + // QScrollBar inherits QWidget and QRangeControl + <a href="qscrollbar.html">QScrollBar</a> *s = new <a href="qscrollbar.html">QScrollBar</a>( 0 ); + s-><a href="#inherits">inherits</a>( "QWidget" ); // returns TRUE + s-><a href="#inherits">inherits</a>( "QRangeControl" ); // returns FALSE + </pre> + +<p> (<a href="qrangecontrol.html">QRangeControl</a> is not a QObject.) +<p> <p>See also <a href="#isA">isA</a>() and <a href="#metaObject">metaObject</a>(). + +<p>Examples: <a href="statistics-example.html#x2783">table/statistics/statistics.cpp</a>, <a href="themes-example.html#x282">themes/metal.cpp</a>, and <a href="themes-example.html#x211">themes/wood.cpp</a>. +<h3 class=fn>void <a name="insertChild"></a>QObject::insertChild ( <a href="qobject.html">QObject</a> * obj )<tt> [virtual]</tt> +</h3> +Inserts an object <em>obj</em> into the list of child objects. +<p> <b>Warning:</b> This function cannot be used to make one widget the child +widget of another widget. Child widgets can only be created by +setting the parent widget in the constructor or by calling +<a href="qwidget.html#reparent">QWidget::reparent</a>(). +<p> <p>See also <a href="#removeChild">removeChild</a>() and <a href="qwidget.html#reparent">QWidget::reparent</a>(). + +<h3 class=fn>void <a name="installEventFilter"></a>QObject::installEventFilter ( const <a href="qobject.html">QObject</a> * filterObj ) +</h3> + +<p> Installs an event filter <em>filterObj</em> on this object. For example: +<pre> + monitoredObj->installEventFilter( filterObj ); + </pre> + +<p> An event filter is an object that receives all events that are +sent to this object. The filter can either stop the event or +forward it to this object. The event filter <em>filterObj</em> receives +events via its <a href="#eventFilter">eventFilter</a>() function. The eventFilter() function +must return TRUE if the event should be filtered, (i.e. stopped); +otherwise it must return FALSE. +<p> If multiple event filters are installed on a single object, the +filter that was installed last is activated first. +<p> Here's a <tt>KeyPressEater</tt> class that eats the key presses of its +monitored objects: +<pre> + class KeyPressEater : public QObject + { + ... + protected: + bool eventFilter( QObject *o, QEvent *e ); + }; + + bool KeyPressEater::<a href="#eventFilter">eventFilter</a>( QObject *o, QEvent *e ) + { + if ( e->type() == QEvent::KeyPress ) { + // special processing for key press + <a href="qkeyevent.html">QKeyEvent</a> *k = (QKeyEvent *)e; + <a href="qapplication.html#qDebug">qDebug</a>( "Ate key press %d", k-><a href="qkeyevent.html#key">key</a>() ); + return TRUE; // eat event + } else { + // standard event processing + return FALSE; + } + } + </pre> + +<p> And here's how to install it on two widgets: +<pre> + KeyPressEater *keyPressEater = new KeyPressEater( this ); + <a href="qpushbutton.html">QPushButton</a> *pushButton = new <a href="qpushbutton.html">QPushButton</a>( this ); + <a href="qlistview.html">QListView</a> *listView = new <a href="qlistview.html">QListView</a>( this ); + + pushButton-><a href="#installEventFilter">installEventFilter</a>( keyPressEater ); + listView-><a href="#installEventFilter">installEventFilter</a>( keyPressEater ); + </pre> + +<p> The <a href="qaccel.html">QAccel</a> class, for example, uses this technique to intercept +accelerator key presses. +<p> <b>Warning:</b> If you delete the receiver object in your <a href="#eventFilter">eventFilter</a>() +function, be sure to return TRUE. If you return FALSE, Qt sends +the event to the deleted object and the program will crash. +<p> <p>See also <a href="#removeEventFilter">removeEventFilter</a>(), <a href="#eventFilter">eventFilter</a>(), and <a href="#event">event</a>(). + +<h3 class=fn>bool <a name="isA"></a>QObject::isA ( const char * clname ) const +</h3> +Returns TRUE if this object is an instance of the class <em>clname</em>; +otherwise returns FALSE. +<p> Example: +<pre> + <a href="qtimer.html">QTimer</a> *t = new <a href="qtimer.html">QTimer</a>; // QTimer inherits QObject + t-><a href="#isA">isA</a>( "QTimer" ); // returns TRUE + t-><a href="#isA">isA</a>( "QObject" ); // returns FALSE + </pre> + +<p> <p>See also <a href="#inherits">inherits</a>() and <a href="#metaObject">metaObject</a>(). + +<h3 class=fn>bool <a name="isWidgetType"></a>QObject::isWidgetType () const +</h3> + +<p> Returns TRUE if the object is a widget; otherwise returns FALSE. +<p> Calling this function is equivalent to calling +<a href="#inherits">inherits</a>("QWidget"), except that it is much faster. + +<h3 class=fn>void <a name="killTimer"></a>QObject::killTimer ( int id ) +</h3> +Kills the timer with timer identifier, <em>id</em>. +<p> The timer identifier is returned by <a href="#startTimer">startTimer</a>() when a timer +event is started. +<p> <p>See also <a href="#timerEvent">timerEvent</a>(), <a href="#startTimer">startTimer</a>(), and <a href="#killTimers">killTimers</a>(). + +<h3 class=fn>void <a name="killTimers"></a>QObject::killTimers () +</h3> +Kills all timers that this object has started. +<p> <b>Warning:</b> Using this function can cause hard-to-find bugs: it kills +timers started by sub- and superclasses as well as those started +by you, which is often not what you want. We recommend using a +<a href="qtimer.html">QTimer</a> or perhaps <a href="#killTimer">killTimer</a>(). +<p> <p>See also <a href="#timerEvent">timerEvent</a>(), <a href="#startTimer">startTimer</a>(), and <a href="#killTimer">killTimer</a>(). + +<h3 class=fn><a href="qmetaobject.html">QMetaObject</a> * <a name="metaObject"></a>QObject::metaObject () const<tt> [virtual]</tt> +</h3> + +<p> Returns a pointer to the <a href="metaobjects.html#meta-object">meta object</a> of this object. +<p> A meta object contains information about a class that inherits +QObject, e.g. class name, superclass name, properties, signals and +slots. Every class that contains the <a href="metaobjects.html#Q_OBJECT">Q_OBJECT</a> macro will also have +a meta object. +<p> The meta object information is required by the signal/slot +connection mechanism and the property system. The functions <a href="#isA">isA</a>() +and <a href="#inherits">inherits</a>() also make use of the meta object. + +<h3 class=fn>const char * <a name="name"></a>QObject::name () const +</h3><p>Returns the name of this object. +See the <a href="qobject.html#name-prop">"name"</a> property for details. +<h3 class=fn>const char * <a name="name-2"></a>QObject::name ( const char * defaultName ) const +</h3> +This is an overloaded member function, provided for convenience. It behaves essentially like the above function. +<p> Returns the name of this object, or <em>defaultName</em> if the object +does not have a name. + +<h3 class=fn><a href="qcstring.html">QCString</a> <a name="normalizeSignalSlot"></a>QObject::normalizeSignalSlot ( const char * signalSlot )<tt> [static protected]</tt> +</h3> +Normlizes the signal or slot definition <em>signalSlot</em> by removing +unnecessary whitespace. + +<h3 class=fn>const <a href="qobjectlist.html">QObjectList</a> * <a name="objectTrees"></a>QObject::objectTrees ()<tt> [static]</tt> +</h3> +Returns a pointer to the list of all object trees (their root +objects), or 0 if there are no objects. +<p> The <a href="qobjectlist.html">QObjectList</a> class is defined in the <a href="qobjectlist-h.html">qobjectlist.h</a> header +file. +<p> The most recent root object created is the <a href="qptrlist.html#first">first</a> object in the list and the first root object added +is the <a href="qptrlist.html#last">last</a> object in the list. +<p> <p>See also <a href="#children">children</a>(), <a href="#parent">parent</a>(), <a href="#insertChild">insertChild</a>(), and <a href="#removeChild">removeChild</a>(). + +<h3 class=fn><a href="qobject.html">QObject</a> * <a name="parent"></a>QObject::parent () const +</h3> + +<p> Returns a pointer to the parent object. +<p> <p>See also <a href="#children">children</a>(). + +<h3 class=fn><a href="qvariant.html">QVariant</a> <a name="property"></a>QObject::property ( const char * name ) const<tt> [virtual]</tt> +</h3> +Returns the value of the object's <em>name</em> property. +<p> If no such property exists, the returned variant is invalid. +<p> Information about all available properties are provided through +the <a href="#metaObject">metaObject</a>(). +<p> <p>See also <a href="#setProperty">setProperty</a>(), <a href="qvariant.html#isValid">QVariant::isValid</a>(), <a href="#metaObject">metaObject</a>(), <a href="qmetaobject.html#propertyNames">QMetaObject::propertyNames</a>(), and <a href="qmetaobject.html#property">QMetaObject::property</a>(). + +<p>Example: <a href="qaxcontainer-example-qutlook.html#x2729">qutlook/centralwidget.cpp</a>. +<h3 class=fn><a href="qobjectlist.html">QObjectList</a> * <a name="queryList"></a>QObject::queryList ( const char * inheritsClass = 0, const char * objName = 0, bool regexpMatch = TRUE, bool recursiveSearch = TRUE ) const +</h3> +Searches the children and optionally grandchildren of this object, +and returns a list of those objects that are named or that match +<em>objName</em> and inherit <em>inheritsClass</em>. If <em>inheritsClass</em> is 0 +(the default), all classes match. If <em>objName</em> is 0 (the +default), all object names match. +<p> If <em>regexpMatch</em> is TRUE (the default), <em>objName</em> is a <a href="qregexp.html#regular-expression">regular expression</a> that the objects's names must match. The syntax is that +of a <a href="qregexp.html">QRegExp</a>. If <em>regexpMatch</em> is FALSE, <em>objName</em> is a string +and object names must match it exactly. +<p> Note that <em>inheritsClass</em> uses single inheritance from QObject, +the way <a href="#inherits">inherits</a>() does. According to inherits(), <a href="qmenubar.html">QMenuBar</a> +inherits <a href="qwidget.html">QWidget</a> but not <a href="qmenudata.html">QMenuData</a>. This does not quite match +reality, but is the best that can be done on the wide variety of +compilers Qt supports. +<p> Finally, if <em>recursiveSearch</em> is TRUE (the default), <a href="#queryList">queryList</a>() +searches <em>n</em>th-generation as well as first-generation children. +<p> If all this seems a bit complex for your needs, the simpler +<a href="#child">child</a>() function may be what you want. +<p> This somewhat contrived example disables all the buttons in this +window: +<pre> + <a href="qobjectlist.html">QObjectList</a> *l = topLevelWidget()->queryList( "QButton" ); + QObjectListIt it( *l ); // iterate over the buttons + QObject *obj; + + while ( (obj = it.current()) != 0 ) { + // for each found object... + ++it; + ((QButton*)obj)->setEnabled( FALSE ); + } + delete l; // delete the list, not the objects + </pre> + +<p> The <a href="qobjectlist.html">QObjectList</a> class is defined in the <a href="qobjectlist-h.html">qobjectlist.h</a> header +file. +<p> <b>Warning:</b> Delete the list as soon you have finished using it. The +list contains pointers that may become invalid at almost any time +without notice (as soon as the user closes a window you may have +dangling pointers, for example). +<p> <p>See also <a href="#child">child</a>(), <a href="#children">children</a>(), <a href="#parent">parent</a>(), <a href="#inherits">inherits</a>(), <a href="#name-prop">name</a>, and <a href="qregexp.html">QRegExp</a>. + +<h3 class=fn>void <a name="removeChild"></a>QObject::removeChild ( <a href="qobject.html">QObject</a> * obj )<tt> [virtual]</tt> +</h3> +Removes the child object <em>obj</em> from the list of children. +<p> <b>Warning:</b> This function will not remove a child widget from the +screen. It will only remove it from the parent widget's list of +children. +<p> <p>See also <a href="#insertChild">insertChild</a>() and <a href="qwidget.html#reparent">QWidget::reparent</a>(). + +<h3 class=fn>void <a name="removeEventFilter"></a>QObject::removeEventFilter ( const <a href="qobject.html">QObject</a> * obj ) +</h3> +Removes an event filter object <em>obj</em> from this object. The +request is ignored if such an event filter has not been installed. +<p> All event filters for this object are automatically removed when +this object is destroyed. +<p> It is always safe to remove an event filter, even during event +filter activation (i.e. from the <a href="#eventFilter">eventFilter</a>() function). +<p> <p>See also <a href="#installEventFilter">installEventFilter</a>(), <a href="#eventFilter">eventFilter</a>(), and <a href="#event">event</a>(). + +<h3 class=fn>const <a href="qobject.html">QObject</a> * <a name="sender"></a>QObject::sender ()<tt> [protected]</tt> +</h3> +Returns a pointer to the object that sent the signal, if called in +a slot activated by a signal; otherwise it returns 0. The pointer +is valid only during the execution of the slot that calls this +function. +<p> The pointer returned by this function becomes invalid if the +sender is destroyed, or if the slot is disconnected from the +sender's signal. +<p> <b>Warning:</b> This function violates the object-oriented principle of +modularity. However, getting access to the sender might be useful +when many signals are connected to a single slot. The sender is +undefined if the slot is called as a normal C++ function. + +<h3 class=fn>void <a name="setName"></a>QObject::setName ( const char * name )<tt> [virtual]</tt> +</h3> +Sets the object's name to <em>name</em>. + +<h3 class=fn>bool <a name="setProperty"></a>QObject::setProperty ( const char * name, const <a href="qvariant.html">QVariant</a> & value )<tt> [virtual]</tt> +</h3> +Sets the value of the object's <em>name</em> property to <em>value</em>. +<p> Returns TRUE if the operation was successful; otherwise returns +FALSE. +<p> Information about all available properties is provided through the +<a href="#metaObject">metaObject</a>(). +<p> <p>See also <a href="#property">property</a>(), <a href="#metaObject">metaObject</a>(), <a href="qmetaobject.html#propertyNames">QMetaObject::propertyNames</a>(), and <a href="qmetaobject.html#property">QMetaObject::property</a>(). + +<p>Example: <a href="qaxcontainer-example-qutlook.html#x2730">qutlook/centralwidget.cpp</a>. +<h3 class=fn>bool <a name="signalsBlocked"></a>QObject::signalsBlocked () const +</h3> + +<p> Returns TRUE if signals are blocked; otherwise returns FALSE. +<p> Signals are not blocked by default. +<p> <p>See also <a href="#blockSignals">blockSignals</a>(). + +<h3 class=fn>int <a name="startTimer"></a>QObject::startTimer ( int interval ) +</h3> +Starts a timer and returns a timer identifier, or returns zero if +it could not start a timer. +<p> A timer event will occur every <em>interval</em> milliseconds until +<a href="#killTimer">killTimer</a>() or <a href="#killTimers">killTimers</a>() is called. If <em>interval</em> is 0, then +the timer event occurs once every time there are no more window +system events to process. +<p> The virtual <a href="#timerEvent">timerEvent</a>() function is called with the <a href="qtimerevent.html">QTimerEvent</a> +event parameter class when a timer event occurs. Reimplement this +function to get timer events. +<p> If multiple timers are running, the <a href="qtimerevent.html#timerId">QTimerEvent::timerId</a>() can be +used to find out which timer was activated. +<p> Example: +<pre> + class MyObject : public QObject + { + Q_OBJECT + public: + MyObject( QObject *parent = 0, const char *name = 0 ); + + protected: + void timerEvent( <a href="qtimerevent.html">QTimerEvent</a> * ); + }; + + MyObject::MyObject( QObject *parent, const char *name ) + : QObject( parent, name ) + { + <a href="#startTimer">startTimer</a>( 50 ); // 50-millisecond timer + <a href="#startTimer">startTimer</a>( 1000 ); // 1-second timer + <a href="#startTimer">startTimer</a>( 60000 ); // 1-minute timer + } + + void MyObject::<a href="#timerEvent">timerEvent</a>( <a href="qtimerevent.html">QTimerEvent</a> *e ) + { + <a href="qapplication.html#qDebug">qDebug</a>( "timer event, id %d", e-><a href="qtimerevent.html#timerId">timerId</a>() ); + } + </pre> + +<p> Note that <a href="qtimer.html">QTimer</a>'s accuracy depends on the underlying operating +system and hardware. Most platforms support an accuracy of 20 ms; +some provide more. If Qt is unable to deliver the requested +number of timer clicks, it will silently discard some. +<p> The QTimer class provides a high-level programming interface with +one-shot timers and timer signals instead of events. +<p> <p>See also <a href="#timerEvent">timerEvent</a>(), <a href="#killTimer">killTimer</a>(), <a href="#killTimers">killTimers</a>(), <a href="qeventloop.html#awake">QEventLoop::awake</a>(), and <a href="qeventloop.html#aboutToBlock">QEventLoop::aboutToBlock</a>(). + +<h3 class=fn>void <a name="timerEvent"></a>QObject::timerEvent ( <a href="qtimerevent.html">QTimerEvent</a> * )<tt> [virtual protected]</tt> +</h3> +This event handler can be reimplemented in a subclass to receive +timer events for the object. +<p> <a href="qtimer.html">QTimer</a> provides a higher-level interface to the timer +functionality, and also more general information about timers. +<p> <p>See also <a href="#startTimer">startTimer</a>(), <a href="#killTimer">killTimer</a>(), <a href="#killTimers">killTimers</a>(), and <a href="#event">event</a>(). + +<p>Examples: <a href="biff-example.html#x1959">biff/biff.cpp</a>, <a href="dclock-example.html#x1102">dclock/dclock.cpp</a>, <a href="forever-example.html#x1048">forever/forever.cpp</a>, <a href="grapher-nsplugin-example.html#x2755">grapher/grapher.cpp</a>, <a href="qmag-example.html#x1781">qmag/qmag.cpp</a>, and <a href="xform-example.html#x1232">xform/xform.cpp</a>. +<h3 class=fn><a href="qstring.html">QString</a> <a name="tr"></a>QObject::tr ( const char * sourceText, const char * comment )<tt> [static]</tt> +</h3> + + +<p> Returns a translated version of <em>sourceText</em>, or <em>sourceText</em> +itself if there is no appropriate translated version. The +translation context is QObject with <em>comment</em> (0 by default). +All QObject subclasses using the <a href="metaobjects.html#Q_OBJECT">Q_OBJECT</a> macro automatically have +a reimplementation of this function with the subclass name as +context. +<p> <b>Warning:</b> This method is reentrant only if all translators are +installed <em>before</em> calling this method. Installing or removing +translators while performing translations is not supported. Doing +so will probably result in crashes or other undesirable behavior. +<p> <p>See also <a href="#trUtf8">trUtf8</a>(), <a href="qapplication.html#translate">QApplication::translate</a>(), and <a href="i18n.html">Internationalization with Qt</a>. + +<p>Example: <a href="qdialog.html#x2130">network/networkprotocol/view.cpp</a>. +<h3 class=fn><a href="qstring.html">QString</a> <a name="trUtf8"></a>QObject::trUtf8 ( const char * sourceText, const char * comment )<tt> [static]</tt> +</h3> + + +<p> Returns a translated version of <em>sourceText</em>, or +<a href="qstring.html#fromUtf8">QString::fromUtf8</a>(<em>sourceText</em>) if there is no appropriate +version. It is otherwise identical to <a href="#tr">tr</a>(<em>sourceText</em>, <em>comment</em>). +<p> <b>Warning:</b> This method is reentrant only if all translators are +installed <em>before</em> calling this method. Installing or removing +translators while performing translations is not supported. Doing +so will probably result in crashes or other undesirable behavior. +<p> <p>See also <a href="#tr">tr</a>() and <a href="qapplication.html#translate">QApplication::translate</a>(). + +<hr><h2>Property Documentation</h2> +<h3 class=fn><a href="qcstring.html">QCString</a> <a name="name-prop"></a>name</h3> +<p>This property holds the name of this object. +<p>You can find an object by name (and type) using <a href="#child">child</a>(). You can +find a set of objects with <a href="#queryList">queryList</a>(). +<p> The object name is set by the constructor or by the <a href="#setName">setName</a>() +function. The object name is not very useful in the current +version of Qt, but will become increasingly important in the +future. +<p> If the object does not have a name, the <a href="#name">name</a>() function returns +"unnamed", so printf() (used in <a href="qapplication.html#qDebug">qDebug</a>()) will not be asked to +output a null pointer. If you want a null pointer to be returned +for unnamed objects, you can call name( 0 ). +<p> <pre> + <a href="qapplication.html#qDebug">qDebug</a>( "MyClass::setPrecision(): (%s) invalid precision %f", + <a href="#name">name</a>(), newPrecision ); + </pre> + +<p> <p>See also <a href="#className">className</a>(), <a href="#child">child</a>(), and <a href="#queryList">queryList</a>(). + +<p>Set this property's value with <a href="#setName">setName</a>() and get this property's value with <a href="#name">name</a>(). +<hr><h2>Related Functions</h2> +<h3 class=fn>void * <a name="qt_find_obj_child"></a>qt_find_obj_child ( <a href="qobject.html">QObject</a> * parent, const char * type, const char * name ) +</h3> + +<p> Returns a pointer to the object named <em>name</em> that inherits <em>type</em> and with a given <em>parent</em>. +<p> Returns 0 if there is no such child. +<p> <pre> + <a href="qlistbox.html">QListBox</a> *c = (QListBox *) <a href="#qt_find_obj_child">qt_find_obj_child</a>( myWidget, "QListBox", + "my list box" ); + if ( c ) + c-><a href="qlistbox.html#insertItem">insertItem</a>( "another string" ); + </pre> + + +<!-- 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> |