<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qgraphicssceneevent.cpp --> <title>QGraphicsSceneEvent Class | Qt Widgets 5.12.6</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 >QGraphicsSceneEvent</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtwidgets-index.html">Qt 5.12.6 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="#public-functions">Public Functions</a></li> <li class="level1"><a href="#protected-variables">Protected Variables</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">QGraphicsSceneEvent Class</h1> <!-- $$$QGraphicsSceneEvent-brief --> <p>The <a href="qgraphicssceneevent.html">QGraphicsSceneEvent</a> class provides a base class for all graphics view related events. <a href="#details">More...</a></p> <!-- @@@QGraphicsSceneEvent --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Header:</td><td class="memItemRight bottomAlign"> <span class="preprocessor">#include <QGraphicsSceneEvent></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 4.2</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Inherits:</td><td class="memItemRight bottomAlign"> <a href="../qtcore/qevent.html">QEvent</a></td></tr><tr><td class="memItemLeft rightAlign topAlign"> Inherited By:</td><td class="memItemRight bottomAlign"> <p><a href="qgraphicsscenecontextmenuevent.html">QGraphicsSceneContextMenuEvent</a>, <a href="qgraphicsscenedragdropevent.html">QGraphicsSceneDragDropEvent</a>, <a href="qgraphicsscenehelpevent.html">QGraphicsSceneHelpEvent</a>, <a href="qgraphicsscenehoverevent.html">QGraphicsSceneHoverEvent</a>, <a href="qgraphicsscenemouseevent.html">QGraphicsSceneMouseEvent</a>, <a href="qgraphicsscenemoveevent.html">QGraphicsSceneMoveEvent</a>, <a href="qgraphicssceneresizeevent.html">QGraphicsSceneResizeEvent</a>, and <a href="qgraphicsscenewheelevent.html">QGraphicsSceneWheelEvent</a></p> </td></tr></table></div><ul> <li><a href="qgraphicssceneevent-members.html">List of all members, including inherited members</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"> virtual </td><td class="memItemRight bottomAlign"><b><a href="qgraphicssceneevent.html#dtor.QGraphicsSceneEvent">~QGraphicsSceneEvent</a></b>()</td></tr> <tr><td class="memItemLeft rightAlign topAlign"> QWidget *</td><td class="memItemRight bottomAlign"><b><a href="qgraphicssceneevent.html#widget">widget</a></b>() const</td></tr> </table></div> <ul> <li class="fn">6 public functions inherited from <a href="../qtcore/qevent.html#public-functions">QEvent</a></li> </ul> <a name="protected-variables"></a> <h2 id="protected-variables">Protected Variables</h2> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> int </td><td class="memItemRight bottomAlign"><b><a href="qgraphicssceneevent.html#d_ptr-var">d_ptr</a></b></td></tr> </table></div> <h3>Additional Inherited Members</h3> <ul> <li class="fn">1 property inherited from <a href="../qtcore/qevent.html#properties">QEvent</a></li> <li class="fn">1 static public member inherited from <a href="../qtcore/qevent.html#static-public-members">QEvent</a></li> </ul> <a name="details"></a> <!-- $$$QGraphicsSceneEvent-description --> <div class="descr"> <h2 id="details">Detailed Description</h2> <p>The <a href="qgraphicssceneevent.html">QGraphicsSceneEvent</a> class provides a base class for all graphics view related events.</p> <p>When a <a href="qgraphicsview.html">QGraphicsView</a> receives Qt mouse, keyboard, and drag and drop events (<a href="../qtgui/qmouseevent.html">QMouseEvent</a>, <a href="../qtgui/qkeyevent.html">QKeyEvent</a>, QDragEvent, etc.), it translates them into instances of <a href="qgraphicssceneevent.html">QGraphicsSceneEvent</a> subclasses and forwards them to the <a href="qgraphicsscene.html">QGraphicsScene</a> it displays. The scene then forwards the events to the relevant items.</p> <p>For example, when a <a href="qgraphicsview.html">QGraphicsView</a> receives a <a href="../qtgui/qmouseevent.html">QMouseEvent</a> of type MousePress as a response to a user click, the view sends a <a href="qgraphicsscenemouseevent.html">QGraphicsSceneMouseEvent</a> of type <a href="../qtcore/qevent.html#Type-enum">GraphicsSceneMousePress</a> to the underlying <a href="qgraphicsscene.html">QGraphicsScene</a> through its <a href="qgraphicsscene.html#mousePressEvent">mousePressEvent()</a> function. The default <a href="qgraphicsscene.html#mousePressEvent">QGraphicsScene::mousePressEvent</a>() implementation determines which item was clicked and forwards the event to <a href="qgraphicsitem.html#mousePressEvent">QGraphicsItem::mousePressEvent</a>().</p> <p>Subclasses such as <a href="qgraphicsscenemouseevent.html">QGraphicsSceneMouseEvent</a> and <a href="qgraphicsscenecontextmenuevent.html">QGraphicsSceneContextMenuEvent</a> provide the coordinates from the original <a href="../qtcore/qevent.html">QEvent</a> in screen, scene, and item coordinates (see <a href="qgraphicsscenemouseevent.html#screenPos">screenPos()</a>, <a href="qgraphicsscenemouseevent.html#scenePos">scenePos()</a>, and <a href="qgraphicsscenemouseevent.html#pos">pos()</a>). The item coordinates are set by the <a href="qgraphicsscene.html">QGraphicsScene</a> before it forwards the event to the event to a <a href="qgraphicsitem.html">QGraphicsItem</a>. The mouse events also add the possibility to retrieve the coordinates from the last event received by the view (see <a href="qgraphicsscenemouseevent.html#lastScreenPos">lastScreenPos()</a>, <a href="qgraphicsscenemouseevent.html#lastScenePos">lastScenePos()</a>, and <a href="qgraphicsscenemouseevent.html#lastPos">lastPos()</a>).</p> </div> <p><b>See also </b><a href="../qtcore/qevent.html">QEvent</a>.</p> <!-- @@@QGraphicsSceneEvent --> <div class="func"> <h2>Member Function Documentation</h2> <!-- $$$~QGraphicsSceneEvent[overload1]$$$~QGraphicsSceneEvent --> <h3 class="fn" id="dtor.QGraphicsSceneEvent"><a name="dtor.QGraphicsSceneEvent"></a><code>[virtual] </code>QGraphicsSceneEvent::<span class="name">~QGraphicsSceneEvent</span>()</h3> <p>Destroys the event.</p> <!-- @@@~QGraphicsSceneEvent --> <!-- $$$widget[overload1]$$$widget --> <h3 class="fn" id="widget"><a name="widget"></a><span class="type"><a href="qwidget.html">QWidget</a></span> *QGraphicsSceneEvent::<span class="name">widget</span>() const</h3> <p>Returns the widget where the event originated, or 0 if the event originates from another application.</p> <!-- @@@widget --> </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>