<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qgraphicseffect.cpp --> <title>QGraphicsOpacityEffect Class | Qt Widgets 5.12.2</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 5.12</td><td ><a href="qtwidgets-index.html">Qt Widgets</a></td><td ><a href="qtwidgets-module.html">C++ Classes</a></td><td >QGraphicsOpacityEffect</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtwidgets-index.html">Qt 5.12.2 Reference Documentation</a></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="#public-functions">Public Functions</a></li> <li class="level1"><a href="#public-slots">Public Slots</a></li> <li class="level1"><a href="#signals">Signals</a></li> <li class="level1"><a href="#static-public-members">Static Public Members</a></li> <li class="level1"><a href="#reimplemented-protected-functions">Reimplemented Protected Functions</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">QGraphicsOpacityEffect Class</h1> <!-- $$$QGraphicsOpacityEffect-brief --> <p>The <a href="qgraphicsopacityeffect.html">QGraphicsOpacityEffect</a> class provides an opacity effect. <a href="#details">More...</a></p> <!-- @@@QGraphicsOpacityEffect --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QGraphicsOpacityEffect></span> </td></tr><tr><td class="memItemLeft rightAlign topAlign"> qmake:</td><td class="memItemRight bottomAlign"> QT += widgets</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Since:</td><td class="memItemRight bottomAlign"> Qt 4.6</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Inherits:</td><td class="memItemRight bottomAlign"> <a href="qgraphicseffect.html">QGraphicsEffect</a></td></tr></table></div><ul> <li><a href="qgraphicsopacityeffect-members.html">List of all members, including inherited members</a></li> <li><a href="qgraphicsopacityeffect-obsolete.html">Obsolete members</a></li> </ul> <a name="properties"></a> <h2 id="properties">Properties</h2> <ul> <li class="fn"><b><a href="qgraphicsopacityeffect.html#opacity-prop">opacity</a></b> : qreal</li> <li class="fn"><b><a href="qgraphicsopacityeffect.html#opacityMask-prop">opacityMask</a></b> : QBrush</li> </ul> <ul> <li class="fn">1 property inherited from <a href="qgraphicseffect.html#properties">QGraphicsEffect</a></li> <li class="fn">1 property inherited from <a href="../qtcore/qobject.html#properties">QObject</a></li> </ul> <a name="public-functions"></a> <h2 id="public-functions">Public Functions</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#QGraphicsOpacityEffect">QGraphicsOpacityEffect</a></b>(QObject *<i>parent</i> = nullptr)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> virtual </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#dtor.QGraphicsOpacityEffect">~QGraphicsOpacityEffect</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> qreal </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#opacity-prop">opacity</a></b>() const</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QBrush </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#opacityMask-prop">opacityMask</a></b>() const</td></tr> </table></div> <ul> <li class="fn">3 public functions inherited from <a href="qgraphicseffect.html#public-functions">QGraphicsEffect</a></li> <li class="fn">31 public functions inherited from <a href="../qtcore/qobject.html#public-functions">QObject</a></li> </ul> <a name="public-slots"></a> <h2 id="public-slots">Public Slots</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#opacity-prop">setOpacity</a></b>(qreal <i>opacity</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#opacityMask-prop">setOpacityMask</a></b>(const QBrush &<i>mask</i>)</td></tr> </table></div> <ul> <li class="fn">2 public slots inherited from <a href="qgraphicseffect.html#public-slots">QGraphicsEffect</a></li> <li class="fn">1 public slot inherited from <a href="../qtcore/qobject.html#public-slots">QObject</a></li> </ul> <a name="signals"></a> <h2 id="signals">Signals</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#opacityChanged">opacityChanged</a></b>(qreal <i>opacity</i>)</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> void </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#opacityMaskChanged">opacityMaskChanged</a></b>(const QBrush &<i>mask</i>)</td></tr> </table></div> <ul> <li class="fn">1 signal inherited from <a href="qgraphicseffect.html#signals">QGraphicsEffect</a></li> <li class="fn">2 signals inherited from <a href="../qtcore/qobject.html#signals">QObject</a></li> </ul> <a name="static-public-members"></a> <h2 id="static-public-members">Static Public Members</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> const QMetaObject </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#staticMetaObject-var">staticMetaObject</a></b></td></tr> </table></div> <ul> <li class="fn">9 static public members inherited from <a href="../qtcore/qobject.html#static-public-members">QObject</a></li> </ul> <a name="reimplemented-protected-functions"></a> <h2 id="reimplemented-protected-functions">Reimplemented Protected Functions</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> virtual void </td><td class="memItemRight bottomAlign"><b><a href="qgraphicsopacityeffect.html#draw">draw</a></b>(QPainter *<i>painter</i>) override</td></tr> </table></div> <ul> <li class="fn">7 protected functions inherited from <a href="qgraphicseffect.html#protected-functions">QGraphicsEffect</a></li> <li class="fn">9 protected functions inherited from <a href="../qtcore/qobject.html#protected-functions">QObject</a></li> </ul> <a name="details"></a> <!-- $$$QGraphicsOpacityEffect-description --> <div class="descr"> <h2 id="details">Detailed Description</h2> <p>The <a href="qgraphicsopacityeffect.html">QGraphicsOpacityEffect</a> class provides an opacity effect.</p> <p>An opacity effect renders the source with an opacity. This effect is useful for making the source semi-transparent, similar to a fade-in/fade-out sequence. The opacity can be modified using the <a href="qgraphicsopacityeffect.html#opacity-prop">setOpacity</a>() function.</p> <p>By default, the opacity is 0.7.</p> <p class="centerAlign"><img src="images/graphicseffect-opacity.png" alt="" /></p></div> <p><b>See also </b><a href="qgraphicsdropshadoweffect.html">QGraphicsDropShadowEffect</a>, <a href="qgraphicsblureffect.html">QGraphicsBlurEffect</a>, and <a href="qgraphicscolorizeeffect.html">QGraphicsColorizeEffect</a>.</p> <!-- @@@QGraphicsOpacityEffect --> <div class="prop"> <h2>Property Documentation</h2> <!-- $$$opacity-prop$$$opacity$$$setOpacityqreal$$$opacityChangedqreal --> <h3 class="fn" id="opacity-prop"><a name="opacity-prop"></a><span class="name">opacity</span> : <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span></h3> <p>This property holds the opacity of the effect.</p> <p>The value should be in the range of 0.0 to 1.0, where 0.0 is fully transparent and 1.0 is fully opaque.</p> <p>By default, the opacity is 0.7.</p> <p><b>Access functions:</b></p> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft topAlign rightAlign"> qreal </td><td class="memItemRight bottomAlign"><span class="name"><b>opacity</b></span>() const</td></tr> <tr><td class="memItemLeft topAlign rightAlign"> void </td><td class="memItemRight bottomAlign"><span class="name"><b>setOpacity</b></span>(qreal <i>opacity</i>)</td></tr> </table></div> <p><b>Notifier signal:</b></p> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft topAlign rightAlign"> void </td><td class="memItemRight bottomAlign"><span class="name"><b><a href="qgraphicsopacityeffect.html#opacityChanged">opacityChanged</a></b></span>(qreal <i>opacity</i>)</td></tr> </table></div> <p><b>See also </b><a href="qgraphicsopacityeffect.html#opacityMask-prop">setOpacityMask</a>().</p> <!-- @@@opacity --> <!-- $$$opacityMask-prop$$$opacityMask$$$setOpacityMaskconstQBrush&$$$opacityMaskChangedconstQBrush& --> <h3 class="fn" id="opacityMask-prop"><a name="opacityMask-prop"></a><span class="name">opacityMask</span> : <span class="type"><a href="../qtgui/qbrush.html">QBrush</a></span></h3> <p>This property holds the opacity mask of the effect.</p> <p>An opacity mask allows you apply opacity to portions of an element.</p> <p>For example:</p> <pre class="cpp"> <span class="operator">.</span><span class="operator">.</span><span class="operator">.</span> <span class="type"><a href="../qtgui/qlineargradient.html">QLinearGradient</a></span> alphaGradient(rect<span class="operator">.</span>topLeft()<span class="operator">,</span> rect<span class="operator">.</span>bottomLeft()); alphaGradient<span class="operator">.</span>setColorAt(<span class="number">0.0</span><span class="operator">,</span> <span class="type">Qt</span><span class="operator">::</span>transparent); alphaGradient<span class="operator">.</span>setColorAt(<span class="number">0.5</span><span class="operator">,</span> <span class="type">Qt</span><span class="operator">::</span>black); alphaGradient<span class="operator">.</span>setColorAt(<span class="number">1.0</span><span class="operator">,</span> <span class="type">Qt</span><span class="operator">::</span>transparent); <span class="type"><a href="qgraphicsopacityeffect.html#QGraphicsOpacityEffect">QGraphicsOpacityEffect</a></span> <span class="operator">*</span>effect <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgraphicsopacityeffect.html#QGraphicsOpacityEffect">QGraphicsOpacityEffect</a></span>; effect<span class="operator">-</span><span class="operator">></span>setOpacityMask(alphaGradient); <span class="operator">.</span><span class="operator">.</span><span class="operator">.</span> </pre> <p>There is no opacity mask by default.</p> <p><b>Access functions:</b></p> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft topAlign rightAlign"> QBrush </td><td class="memItemRight bottomAlign"><span class="name"><b>opacityMask</b></span>() const</td></tr> <tr><td class="memItemLeft topAlign rightAlign"> void </td><td class="memItemRight bottomAlign"><span class="name"><b>setOpacityMask</b></span>(const QBrush &<i>mask</i>)</td></tr> </table></div> <p><b>Notifier signal:</b></p> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft topAlign rightAlign"> void </td><td class="memItemRight bottomAlign"><span class="name"><b><a href="qgraphicsopacityeffect.html#opacityMaskChanged">opacityMaskChanged</a></b></span>(const QBrush &<i>mask</i>)</td></tr> </table></div> <p><b>See also </b><a href="qgraphicsopacityeffect.html#opacity-prop">setOpacity</a>().</p> <!-- @@@opacityMask --> </div> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$QGraphicsOpacityEffect[overload1]$$$QGraphicsOpacityEffectQObject* --> <h3 class="fn" id="QGraphicsOpacityEffect"><a name="QGraphicsOpacityEffect"></a>QGraphicsOpacityEffect::<span class="name">QGraphicsOpacityEffect</span>(<span class="type"><a href="../qtcore/qobject.html#QObject">QObject</a></span> *<i>parent</i> = nullptr)</h3> <p>Constructs a new <a href="qgraphicsopacityeffect.html">QGraphicsOpacityEffect</a> instance. The <i>parent</i> parameter is passed to <a href="qgraphicseffect.html">QGraphicsEffect</a>'s constructor.</p> <!-- @@@QGraphicsOpacityEffect --> <!-- $$$~QGraphicsOpacityEffect[overload1]$$$~QGraphicsOpacityEffect --> <h3 class="fn" id="dtor.QGraphicsOpacityEffect"><a name="dtor.QGraphicsOpacityEffect"></a><code>[virtual] </code>QGraphicsOpacityEffect::<span class="name">~QGraphicsOpacityEffect</span>()</h3> <p>Destroys the effect.</p> <!-- @@@~QGraphicsOpacityEffect --> <!-- $$$draw[overload1]$$$drawQPainter* --> <h3 class="fn" id="draw"><a name="draw"></a><code>[override virtual protected] </code><span class="type">void</span> QGraphicsOpacityEffect::<span class="name">draw</span>(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> *<i>painter</i>)</h3> <p>Reimplemented from <a href="qgraphicseffect.html#draw">QGraphicsEffect::draw</a>().</p> <!-- @@@draw --> <!-- $$$opacityChanged --> <h3 class="fn" id="opacityChanged"><a name="opacityChanged"></a><code>[signal] </code><span class="type">void</span> QGraphicsOpacityEffect::<span class="name">opacityChanged</span>(<span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> <i>opacity</i>)</h3> <p>This signal is emitted whenever the effect's opacity changes. The <i>opacity</i> parameter holds the effect's new opacity.</p> <p><b>Note:</b> Notifier signal for property <a href="qgraphicsopacityeffect.html#opacity-prop">opacity</a>. </p><!-- @@@opacityChanged --> <!-- $$$opacityMaskChanged --> <h3 class="fn" id="opacityMaskChanged"><a name="opacityMaskChanged"></a><code>[signal] </code><span class="type">void</span> QGraphicsOpacityEffect::<span class="name">opacityMaskChanged</span>(const <span class="type"><a href="../qtgui/qbrush.html">QBrush</a></span> &<i>mask</i>)</h3> <p>This signal is emitted whenever the effect's opacity mask changes. The <i>mask</i> parameter holds the effect's new opacity mask.</p> <p><b>Note:</b> Notifier signal for property <a href="qgraphicsopacityeffect.html#opacityMask-prop">opacityMask</a>. </p><!-- @@@opacityMaskChanged --> </div> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2019 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>