<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qquickbehavior.cpp --> <title>Behavior QML Type | Qt Quick 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="qtquick-index.html">Qt Quick</a></td><td ><a href="qtquick-qmlmodule.html">QML Types</a></td><td >Behavior 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="#details">Detailed Description</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">Behavior QML Type</h1> <span class="subtitle"></span> <!-- $$$Behavior-brief --> <p>Defines a default animation for a property change <a href="#details">More...</a></p> <!-- @@@Behavior --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Import Statement:</td><td class="memItemRight bottomAlign"> import QtQuick 2.7</td></tr></table></div><ul> <li><a href="qml-qtquick-behavior-members.html">List of all members, including inherited members</a></li> </ul> <a name="properties"></a> <h2 id="properties">Properties</h2> <ul> <li class="fn"><b><b><a href="qml-qtquick-behavior.html#animation-prop">animation</a></b></b> : Animation</li> <li class="fn"><b><b><a href="qml-qtquick-behavior.html#enabled-prop">enabled</a></b></b> : bool</li> </ul> <!-- $$$Behavior-description --> <a name="details"></a> <h2 id="details">Detailed Description</h2> <p>A Behavior defines the default animation to be applied whenever a particular property value changes.</p> <p>For example, the following Behavior defines a <a href="qml-qtquick-numberanimation.html">NumberAnimation</a> to be run whenever the <a href="qml-qtquick-rectangle.html">Rectangle</a>'s <code>width</code> value changes. When the <a href="qml-qtquick-mousearea.html">MouseArea</a> is clicked, the <code>width</code> is changed, triggering the behavior's animation:</p> <pre class="qml"> import QtQuick 2.0 <span class="type"><a href="qml-qtquick-rectangle.html">Rectangle</a></span> { <span class="name">id</span>: <span class="name">rect</span> <span class="name">width</span>: <span class="number">100</span>; <span class="name">height</span>: <span class="number">100</span> <span class="name">color</span>: <span class="string">"red"</span> Behavior on <span class="name">width</span> { <span class="type"><a href="qml-qtquick-numberanimation.html">NumberAnimation</a></span> { <span class="name">duration</span>: <span class="number">1000</span> } } <span class="type"><a href="qml-qtquick-mousearea.html">MouseArea</a></span> { <span class="name">anchors</span>.fill: <span class="name">parent</span> <span class="name">onClicked</span>: <span class="name">rect</span>.<span class="name">width</span> <span class="operator">=</span> <span class="number">50</span> } } </pre> <p>Note that a property cannot have more than one assigned Behavior. To provide multiple animations within a Behavior, use <a href="qml-qtquick-parallelanimation.html">ParallelAnimation</a> or <a href="qml-qtquick-sequentialanimation.html">SequentialAnimation</a>.</p> <p>If a <a href="qtquick-statesanimations-states.html">state change</a> has a <a href="qmlexampletoggleswitch.html#transition">Transition</a> that matches the same property as a Behavior, the <a href="qmlexampletoggleswitch.html#transition">Transition</a> animation overrides the Behavior for that state change. For general advice on using Behaviors to animate state changes, see <a href="qtquick-statesanimations-behaviors.html">Using Qt Quick Behaviors with States</a>.</p> <p><b>See also </b><a href="qtquick-statesanimations-animations.html">Animation and Transitions in Qt Quick</a>, <a href="qtquick-animation-example.html#behaviors">Behavior example</a>, and Qt QML.</p> <!-- @@@Behavior --> <h2>Property Documentation</h2> <!-- $$$animation --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="animation-prop"> <td class="tblQmlPropNode"><p> <a name="animation-prop"></a><span class="qmldefault">[default] </span><span class="name">animation</span> : <span class="type"><a href="qml-qtquick-animation.html">Animation</a></span></p></td></tr> </table></div> </div><div class="qmldoc"><p>This property holds the animation to run when the behavior is triggered.</p> </div></div><!-- @@@animation --> <br/> <!-- $$$enabled --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="enabled-prop"> <td class="tblQmlPropNode"><p> <a name="enabled-prop"></a><span class="name">enabled</span> : <span class="type">bool</span></p></td></tr> </table></div> </div><div class="qmldoc"><p>This property holds whether the behavior will be triggered when the tracked property changes value.</p> <p>By default a Behavior is enabled.</p> </div></div><!-- @@@enabled --> <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>