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Breadcrumbs go here --> <li><a href="qdeclarativeelements.html">QML Elements</a></li> <li>QML Timer Element</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="#properties">Properties</a></li> <li class="level1"><a href="#signal-handlers">Signal Handlers</a></li> <li class="level1"><a href="#methods">Methods</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <h1 class="title">QML Timer Element</h1> <span class="subtitle"></span> <!-- $$$Timer-brief --> <p>The Timer item triggers a handler at a specified interval. <a href="#details">More...</a></p> <!-- @@@Timer --> <p>This element was introduced in Qt 4.7.</p> <ul> <li><a href="qml-timer-members.html">List of all members, including inherited members</a></li> </ul> <a name="properties"></a> <h2>Properties</h2> <ul> <li class="fn"><b><b><a href="qml-timer.html#interval-prop">interval</a></b></b> : int</li> <li class="fn"><b><b><a href="qml-timer.html#repeat-prop">repeat</a></b></b> : bool</li> <li class="fn"><b><b><a href="qml-timer.html#running-prop">running</a></b></b> : bool</li> <li class="fn"><b><b><a href="qml-timer.html#triggeredOnStart-prop">triggeredOnStart</a></b></b> : bool</li> </ul> <a name="signal-handlers"></a> <h2>Signal Handlers</h2> <ul> <li class="fn"><b><b><a href="qml-timer.html#onTriggered-signal">onTriggered</a></b></b></li> </ul> <a name="methods"></a> <h2>Methods</h2> <ul> <li class="fn"><b><b><a href="qml-timer.html#restart-method">restart</a></b></b></li> <li class="fn"><b><b><a href="qml-timer.html#start-method">start</a></b></b></li> <li class="fn"><b><b><a href="qml-timer.html#stop-method">stop</a></b></b></li> </ul> <!-- $$$Timer-description --> <a name="details"></a> <h2>Detailed Description</h2> <p>A Timer can be used to trigger an action either once, or repeatedly at a given interval.</p> <p>Here is a Timer that shows the current date and time, and updates the text every 500 milliseconds. It uses the JavaScript <tt>Date</tt> object to access the current time.</p> <pre class="qml"> import QtQuick 1.0 <span class="type"><a href="qml-item.html">Item</a></span> { <span class="type">Timer</span> { <span class="name">interval</span>: <span class="number">500</span>; <span class="name">running</span>: <span class="number">true</span>; <span class="name">repeat</span>: <span class="number">true</span> <span class="name">onTriggered</span>: <span class="name">time</span>.<span class="name">text</span> <span class="operator">=</span> <span class="name">Date</span>().<span class="name">toString</span>() } <span class="type"><a href="qml-text.html">Text</a></span> { <span class="name">id</span>: <span class="name">time</span> } }</pre> <p>The Timer element is synchronized with the animation timer. Since the animation timer is usually set to 60fps, the resolution of Timer will be at best 16ms.</p> <p>If the Timer is running and one of its properties is changed, the elapsed time will be reset. For example, if a Timer with interval of 1000ms has its <i>repeat</i> property changed 500ms after starting, the elapsed time will be reset to 0, and the Timer will be triggered 1000ms later.</p> <p><b>See also </b><a href="declarative-toys-clocks.html">Clocks example</a>.</p> <!-- @@@Timer --> <h2>Property Documentation</h2> <!-- $$$interval --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="interval-prop"></a><span class="name">interval</span> : <span class="type"><a href="qml-int.html">int</a></span></p></td></tr></table></div><div class="qmldoc"><p>Sets the <i>interval</i> between triggers, in milliseconds.</p> <p>The default interval is 1000 milliseconds.</p> </div></div><!-- @@@interval --> <br/> <!-- $$$repeat --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="repeat-prop"></a><span class="name">repeat</span> : <span class="type"><a href="qml-bool.html">bool</a></span></p></td></tr></table></div><div class="qmldoc"><p>If <i>repeat</i> is true the timer is triggered repeatedly at the specified interval; otherwise, the timer will trigger once at the specified interval and then stop (i.e. running will be set to false).</p> <p><i>repeat</i> defaults to false.</p> <p><b>See also </b><a href="qml-timer.html#running-prop">running</a>.</p> </div></div><!-- @@@repeat --> <br/> <!-- $$$running --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="running-prop"></a><span class="name">running</span> : <span class="type"><a href="qml-bool.html">bool</a></span></p></td></tr></table></div><div class="qmldoc"><p>If set to true, starts the timer; otherwise stops the timer. For a non-repeating timer, <i>running</i> is set to false after the timer has been triggered.</p> <p><i>running</i> defaults to false.</p> <p><b>See also </b><a href="qml-timer.html#repeat-prop">repeat</a>.</p> </div></div><!-- @@@running --> <br/> <!-- $$$triggeredOnStart --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlPropNode"><p><a name="triggeredOnStart-prop"></a><span class="name">triggeredOnStart</span> : <span class="type"><a href="qml-bool.html">bool</a></span></p></td></tr></table></div><div class="qmldoc"><p>When a timer is started, the first trigger is usually after the specified interval has elapsed. It is sometimes desirable to trigger immediately when the timer is started; for example, to establish an initial state.</p> <p>If <i>triggeredOnStart</i> is true, the timer is triggered immediately when started, and subsequently at the specified interval. Note that if <i>repeat</i> is set to false, the timer is triggered twice; once on start, and again at the interval.</p> <p><i>triggeredOnStart</i> defaults to false.</p> <p><b>See also </b><a href="qml-timer.html#running-prop">running</a>.</p> </div></div><!-- @@@triggeredOnStart --> <br/> <h2>Signal Handler Documentation</h2> <!-- $$$onTriggered --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlFuncNode"><p><a name="onTriggered-signal"></a>Timer::<span class="name">onTriggered</span> ()</p></td></tr></table></div><div class="qmldoc"><p>This handler is called when the Timer is triggered.</p> </div></div><!-- @@@onTriggered --> <br/> <h2>Method Documentation</h2> <!-- $$$restart --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlFuncNode"><p><a name="restart-method"></a>Timer::<span class="name">restart</span> ()</p></td></tr></table></div><div class="qmldoc"><p>Restarts the timer.</p> <p>If the Timer is not running it will be started, otherwise it will be stopped, reset to initial state and started. The <tt>running</tt> property will be true following a call to <tt>restart()</tt>.</p> </div></div><!-- @@@restart --> <br/> <!-- $$$start --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlFuncNode"><p><a name="start-method"></a>Timer::<span class="name">start</span> ()</p></td></tr></table></div><div class="qmldoc"><p>Starts the timer.</p> <p>If the timer is already running, calling this method has no effect. The <tt>running</tt> property will be true following a call to <tt>start()</tt>.</p> </div></div><!-- @@@start --> <br/> <!-- $$$stop --> <div class="qmlitem"><div class="qmlproto"><table class="qmlname"><tr valign="top" class="odd"><td class="tblQmlFuncNode"><p><a name="stop-method"></a>Timer::<span class="name">stop</span> ()</p></td></tr></table></div><div class="qmldoc"><p>Stops the timer.</p> <p>If the timer is not running, calling this method has no effect. The <tt>running</tt> property will be false following a call to <tt>stop()</tt>.</p> </div></div><!-- @@@stop --> <br/> </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. Documentation contributions included herein are the copyrights of their respective owners.</p> <br /> <p> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.</p> <p> Documentation sources may be obtained from <a href="http://www.qt-project.org"> www.qt-project.org</a>.</p> <br /> <p> Digia, Qt and their respective logos are trademarks of Digia Plc in Finland and/or other countries worldwide. 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