<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>node.cpp Example File | 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-graphicsview-elasticnodes-example.html">Elastic Nodes Example</a></td><td >node.cpp Example File</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="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">node.cpp Example File</h1> <span class="subtitle">graphicsview/elasticnodes/node.cpp</span> <!-- $$$graphicsview/elasticnodes/node.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2016 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the examples of the Qt Toolkit. ** ** $QT_BEGIN_LICENSE:BSD$ ** Commercial License Usage ** Licensees holding valid commercial Qt licenses may use this file in ** accordance with the commercial license agreement provided with the ** Software or, alternatively, in accordance with the terms contained in ** a written agreement between you and The Qt Company. For licensing terms ** and conditions see https://www.qt.io/terms-conditions. For further ** information use the contact form at https://www.qt.io/contact-us. ** ** BSD License Usage ** Alternatively, you may use this file under the terms of the BSD license ** as follows: ** ** "Redistribution and use in source and binary forms, with or without ** modification, are permitted provided that the following conditions are ** met: ** * Redistributions of source code must retain the above copyright ** notice, this list of conditions and the following disclaimer. ** * Redistributions in binary form must reproduce the above copyright ** notice, this list of conditions and the following disclaimer in ** the documentation and/or other materials provided with the ** distribution. ** * Neither the name of The Qt Company Ltd nor the names of its ** contributors may be used to endorse or promote products derived ** from this software without specific prior written permission. ** ** ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." ** ** $QT_END_LICENSE$ ** ****************************************************************************/</span> <span class="preprocessor">#include "edge.h"</span> <span class="preprocessor">#include "node.h"</span> <span class="preprocessor">#include "graphwidget.h"</span> <span class="preprocessor">#include <QGraphicsScene></span> <span class="preprocessor">#include <QGraphicsSceneMouseEvent></span> <span class="preprocessor">#include <QPainter></span> <span class="preprocessor">#include <QStyleOption></span> Node<span class="operator">::</span>Node(GraphWidget <span class="operator">*</span>graphWidget) : graph(graphWidget) { setFlag(ItemIsMovable); setFlag(ItemSendsGeometryChanges); setCacheMode(DeviceCoordinateCache); setZValue(<span class="operator">-</span><span class="number">1</span>); } <span class="type">void</span> Node<span class="operator">::</span>addEdge(Edge <span class="operator">*</span>edge) { edgeList <span class="operator"><</span><span class="operator"><</span> edge; edge<span class="operator">-</span><span class="operator">></span>adjust(); } <span class="type"><a href="../qtcore/qlist.html">QList</a></span><span class="operator"><</span>Edge <span class="operator">*</span><span class="operator">></span> Node<span class="operator">::</span>edges() <span class="keyword">const</span> { <span class="keyword">return</span> edgeList; } <span class="type">void</span> Node<span class="operator">::</span>calculateForces() { <span class="keyword">if</span> (<span class="operator">!</span>scene() <span class="operator">|</span><span class="operator">|</span> scene()<span class="operator">-</span><span class="operator">></span>mouseGrabberItem() <span class="operator">=</span><span class="operator">=</span> <span class="keyword">this</span>) { newPos <span class="operator">=</span> pos(); <span class="keyword">return</span>; } <span class="comment">// Sum up all forces pushing this item away</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> xvel <span class="operator">=</span> <span class="number">0</span>; <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> yvel <span class="operator">=</span> <span class="number">0</span>; foreach (<span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span> <span class="operator">*</span>item<span class="operator">,</span> scene()<span class="operator">-</span><span class="operator">></span>items()) { Node <span class="operator">*</span>node <span class="operator">=</span> qgraphicsitem_cast<span class="operator"><</span>Node <span class="operator">*</span><span class="operator">></span>(item); <span class="keyword">if</span> (<span class="operator">!</span>node) <span class="keyword">continue</span>; <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span> vec <span class="operator">=</span> mapToItem(node<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span>); <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> dx <span class="operator">=</span> vec<span class="operator">.</span>x(); <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> dy <span class="operator">=</span> vec<span class="operator">.</span>y(); <span class="type">double</span> l <span class="operator">=</span> <span class="number">2.0</span> <span class="operator">*</span> (dx <span class="operator">*</span> dx <span class="operator">+</span> dy <span class="operator">*</span> dy); <span class="keyword">if</span> (l <span class="operator">></span> <span class="number">0</span>) { xvel <span class="operator">+</span><span class="operator">=</span> (dx <span class="operator">*</span> <span class="number">150.0</span>) <span class="operator">/</span> l; yvel <span class="operator">+</span><span class="operator">=</span> (dy <span class="operator">*</span> <span class="number">150.0</span>) <span class="operator">/</span> l; } } <span class="comment">// Now subtract all forces pulling items together</span> <span class="type">double</span> weight <span class="operator">=</span> (edgeList<span class="operator">.</span>size() <span class="operator">+</span> <span class="number">1</span>) <span class="operator">*</span> <span class="number">10</span>; foreach (Edge <span class="operator">*</span>edge<span class="operator">,</span> edgeList) { <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span> vec; <span class="keyword">if</span> (edge<span class="operator">-</span><span class="operator">></span>sourceNode() <span class="operator">=</span><span class="operator">=</span> <span class="keyword">this</span>) vec <span class="operator">=</span> mapToItem(edge<span class="operator">-</span><span class="operator">></span>destNode()<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span>); <span class="keyword">else</span> vec <span class="operator">=</span> mapToItem(edge<span class="operator">-</span><span class="operator">></span>sourceNode()<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span>); xvel <span class="operator">-</span><span class="operator">=</span> vec<span class="operator">.</span>x() <span class="operator">/</span> weight; yvel <span class="operator">-</span><span class="operator">=</span> vec<span class="operator">.</span>y() <span class="operator">/</span> weight; } <span class="keyword">if</span> (<a href="../qtcore/qtglobal.html#qAbs">qAbs</a>(xvel) <span class="operator"><</span> <span class="number">0.1</span> <span class="operator">&</span><span class="operator">&</span> <a href="../qtcore/qtglobal.html#qAbs">qAbs</a>(yvel) <span class="operator"><</span> <span class="number">0.1</span>) xvel <span class="operator">=</span> yvel <span class="operator">=</span> <span class="number">0</span>; <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> sceneRect <span class="operator">=</span> scene()<span class="operator">-</span><span class="operator">></span>sceneRect(); newPos <span class="operator">=</span> pos() <span class="operator">+</span> <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span>(xvel<span class="operator">,</span> yvel); newPos<span class="operator">.</span>setX(<a href="../qtcore/qtglobal.html#qMin">qMin</a>(<a href="../qtcore/qtglobal.html#qMax">qMax</a>(newPos<span class="operator">.</span>x()<span class="operator">,</span> sceneRect<span class="operator">.</span>left() <span class="operator">+</span> <span class="number">10</span>)<span class="operator">,</span> sceneRect<span class="operator">.</span>right() <span class="operator">-</span> <span class="number">10</span>)); newPos<span class="operator">.</span>setY(<a href="../qtcore/qtglobal.html#qMin">qMin</a>(<a href="../qtcore/qtglobal.html#qMax">qMax</a>(newPos<span class="operator">.</span>y()<span class="operator">,</span> sceneRect<span class="operator">.</span>top() <span class="operator">+</span> <span class="number">10</span>)<span class="operator">,</span> sceneRect<span class="operator">.</span>bottom() <span class="operator">-</span> <span class="number">10</span>)); } bool Node<span class="operator">::</span>advancePosition() { <span class="keyword">if</span> (newPos <span class="operator">=</span><span class="operator">=</span> pos()) <span class="keyword">return</span> <span class="keyword">false</span>; setPos(newPos); <span class="keyword">return</span> <span class="keyword">true</span>; } <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> Node<span class="operator">::</span>boundingRect() <span class="keyword">const</span> { <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> adjust <span class="operator">=</span> <span class="number">2</span>; <span class="keyword">return</span> <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span>( <span class="operator">-</span><span class="number">10</span> <span class="operator">-</span> adjust<span class="operator">,</span> <span class="operator">-</span><span class="number">10</span> <span class="operator">-</span> adjust<span class="operator">,</span> <span class="number">23</span> <span class="operator">+</span> adjust<span class="operator">,</span> <span class="number">23</span> <span class="operator">+</span> adjust); } <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> Node<span class="operator">::</span>shape() <span class="keyword">const</span> { <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> path; path<span class="operator">.</span>addEllipse(<span class="operator">-</span><span class="number">10</span><span class="operator">,</span> <span class="operator">-</span><span class="number">10</span><span class="operator">,</span> <span class="number">20</span><span class="operator">,</span> <span class="number">20</span>); <span class="keyword">return</span> path; } <span class="type">void</span> Node<span class="operator">::</span>paint(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> <span class="operator">*</span>painter<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="qstyleoptiongraphicsitem.html">QStyleOptionGraphicsItem</a></span> <span class="operator">*</span>option<span class="operator">,</span> <span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>) { painter<span class="operator">-</span><span class="operator">></span>setPen(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>NoPen); painter<span class="operator">-</span><span class="operator">></span>setBrush(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>darkGray); painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="operator">-</span><span class="number">7</span><span class="operator">,</span> <span class="operator">-</span><span class="number">7</span><span class="operator">,</span> <span class="number">20</span><span class="operator">,</span> <span class="number">20</span>); <span class="type"><a href="../qtgui/qradialgradient.html">QRadialGradient</a></span> gradient(<span class="operator">-</span><span class="number">3</span><span class="operator">,</span> <span class="operator">-</span><span class="number">3</span><span class="operator">,</span> <span class="number">10</span>); <span class="keyword">if</span> (option<span class="operator">-</span><span class="operator">></span>state <span class="operator">&</span> <span class="type"><a href="qstyle.html">QStyle</a></span><span class="operator">::</span>State_Sunken) { gradient<span class="operator">.</span>setCenter(<span class="number">3</span><span class="operator">,</span> <span class="number">3</span>); gradient<span class="operator">.</span>setFocalPoint(<span class="number">3</span><span class="operator">,</span> <span class="number">3</span>); gradient<span class="operator">.</span>setColorAt(<span class="number">1</span><span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>yellow)<span class="operator">.</span>light(<span class="number">120</span>)); gradient<span class="operator">.</span>setColorAt(<span class="number">0</span><span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>darkYellow)<span class="operator">.</span>light(<span class="number">120</span>)); } <span class="keyword">else</span> { gradient<span class="operator">.</span>setColorAt(<span class="number">0</span><span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>yellow); gradient<span class="operator">.</span>setColorAt(<span class="number">1</span><span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>darkYellow); } painter<span class="operator">-</span><span class="operator">></span>setBrush(gradient); painter<span class="operator">-</span><span class="operator">></span>setPen(<span class="type"><a href="../qtgui/qpen.html">QPen</a></span>(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>black<span class="operator">,</span> <span class="number">0</span>)); painter<span class="operator">-</span><span class="operator">></span>drawEllipse(<span class="operator">-</span><span class="number">10</span><span class="operator">,</span> <span class="operator">-</span><span class="number">10</span><span class="operator">,</span> <span class="number">20</span><span class="operator">,</span> <span class="number">20</span>); } <span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span> Node<span class="operator">::</span>itemChange(GraphicsItemChange change<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="../qtcore/qvariant.html">QVariant</a></span> <span class="operator">&</span>value) { <span class="keyword">switch</span> (change) { <span class="keyword">case</span> ItemPositionHasChanged: foreach (Edge <span class="operator">*</span>edge<span class="operator">,</span> edgeList) edge<span class="operator">-</span><span class="operator">></span>adjust(); graph<span class="operator">-</span><span class="operator">></span>itemMoved(); <span class="keyword">break</span>; <span class="keyword">default</span>: <span class="keyword">break</span>; }; <span class="keyword">return</span> <span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span><span class="operator">::</span>itemChange(change<span class="operator">,</span> value); } <span class="type">void</span> Node<span class="operator">::</span>mousePressEvent(<span class="type"><a href="qgraphicsscenemouseevent.html">QGraphicsSceneMouseEvent</a></span> <span class="operator">*</span>event) { update(); <span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span><span class="operator">::</span>mousePressEvent(event); } <span class="type">void</span> Node<span class="operator">::</span>mouseReleaseEvent(<span class="type"><a href="qgraphicsscenemouseevent.html">QGraphicsSceneMouseEvent</a></span> <span class="operator">*</span>event) { update(); <span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span><span class="operator">::</span>mouseReleaseEvent(event); } </pre> </div> <!-- @@@graphicsview/elasticnodes/node.cpp --> </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>