<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qqmltimer.cpp --> <title>Timer QML Type | Qt QML 5.9</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.9</td><td ><a href="qtqml-index.html">Qt QML</a></td><td ><a href="qtqml-qmlmodule.html">QML Types</a></td><td >Timer QML Type</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <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="#signals">Signals</a></li> <li class="level1"><a href="#methods">Methods</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">Timer QML Type</h1> <span class="subtitle"></span> <!-- $$$Timer-brief --> <p>Triggers a handler at a specified interval <a href="#details">More...</a></p> <!-- @@@Timer --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Import Statement:</td><td class="memItemRight bottomAlign"> import QtQml 2.2</td></tr></table></div><ul> <li><a href="qml-qtqml-timer-members.html">List of all members, including inherited members</a></li> </ul> <a name="properties"></a> <h2 id="properties">Properties</h2> <ul> <li class="fn"><b><b><a href="qml-qtqml-timer.html#interval-prop">interval</a></b></b> : int</li> <li class="fn"><b><b><a href="qml-qtqml-timer.html#repeat-prop">repeat</a></b></b> : bool</li> <li class="fn"><b><b><a href="qml-qtqml-timer.html#running-prop">running</a></b></b> : bool</li> <li class="fn"><b><b><a href="qml-qtqml-timer.html#triggeredOnStart-prop">triggeredOnStart</a></b></b> : bool</li> </ul> <a name="signals"></a> <h2 id="signals">Signals</h2> <ul> <li class="fn"><b><b><a href="qml-qtqml-timer.html#triggered-signal">triggered</a></b></b>()</li> </ul> <a name="methods"></a> <h2 id="methods">Methods</h2> <ul> <li class="fn"><b><b><a href="qml-qtqml-timer.html#restart-method">restart</a></b></b>()</li> <li class="fn"><b><b><a href="qml-qtqml-timer.html#start-method">start</a></b></b>()</li> <li class="fn"><b><b><a href="qml-qtqml-timer.html#stop-method">stop</a></b></b>()</li> </ul> <!-- $$$Timer-description --> <a name="details"></a> <h2 id="details">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 <code>Date</code> object to access the current time.</p> <pre class="qml"> import QtQuick 2.0 <span class="type">Item</span> { <span class="type"><a href="qml-qtqml-timer.html">Timer</a></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">Text</span> { <span class="name">id</span>: <span class="name">time</span> } } </pre> <p>The Timer type 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>Qt Quick Demo - Clocks.</p> <!-- @@@Timer --> <h2>Property Documentation</h2> <!-- $$$interval --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="interval-prop"> <td class="tblQmlPropNode"><p> <a name="interval-prop"></a><span class="name">interval</span> : <span class="type">int</span></p></td></tr> </table></div> </div><div class="qmldoc"><p>Sets the <i>interval</i> between triggers, in milliseconds.</p> <p>The default interval is 1000 milliseconds.</p> </div></div><!-- @@@interval --> <br/> <!-- $$$repeat --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="repeat-prop"> <td class="tblQmlPropNode"><p> <a name="repeat-prop"></a><span class="name">repeat</span> : <span class="type">bool</span></p></td></tr> </table></div> </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-qtqml-timer.html#running-prop">running</a>.</p> </div></div><!-- @@@repeat --> <br/> <!-- $$$running --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="running-prop"> <td class="tblQmlPropNode"><p> <a name="running-prop"></a><span class="name">running</span> : <span class="type">bool</span></p></td></tr> </table></div> </div><div class="qmldoc"><p>If set to true, starts the timer; otherwise stops the timer. For a non-repeating timer, <i>running</i> is set to false after the timer has been triggered.</p> <p><i>running</i> defaults to false.</p> <p><b>See also </b><a href="qml-qtqml-timer.html#repeat-prop">repeat</a>.</p> </div></div><!-- @@@running --> <br/> <!-- $$$triggeredOnStart --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="triggeredOnStart-prop"> <td class="tblQmlPropNode"><p> <a name="triggeredOnStart-prop"></a><span class="name">triggeredOnStart</span> : <span class="type">bool</span></p></td></tr> </table></div> </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-qtqml-timer.html#running-prop">running</a>.</p> </div></div><!-- @@@triggeredOnStart --> <br/> <h2>Signal Documentation</h2> <!-- $$$triggered --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="triggered-signal"> <td class="tblQmlFuncNode"><p> <a name="triggered-signal"></a><span class="name">triggered</span>()</p></td></tr> </table></div> </div><div class="qmldoc"><p>This signal is emitted when the Timer times out.</p> <p>The corresponding handler is <code>onTriggered</code>.</p> </div></div><!-- @@@triggered --> <br/> <h2>Method Documentation</h2> <!-- $$$restart --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="restart-method"> <td class="tblQmlFuncNode"><p> <a name="restart-method"></a><span class="name">restart</span>()</p></td></tr> </table></div> </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 <code>running</code> property will be true following a call to <code>restart()</code>.</p> </div></div><!-- @@@restart --> <br/> <!-- $$$start --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="start-method"> <td class="tblQmlFuncNode"><p> <a name="start-method"></a><span class="name">start</span>()</p></td></tr> </table></div> </div><div class="qmldoc"><p>Starts the timer</p> <p>If the timer is already running, calling this method has no effect. The <code>running</code> property will be true following a call to <code>start()</code>.</p> </div></div><!-- @@@start --> <br/> <!-- $$$stop --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="stop-method"> <td class="tblQmlFuncNode"><p> <a name="stop-method"></a><span class="name">stop</span>()</p></td></tr> </table></div> </div><div class="qmldoc"><p>Stops the timer</p> <p>If the timer is not running, calling this method has no effect. The <code>running</code> property will be false following a call to <code>stop()</code>.</p> </div></div><!-- @@@stop --> <br/> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2017 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br> 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.<br> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>