<?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>graphwidget.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 >graphwidget.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">graphwidget.cpp Example File</h1> <span class="subtitle">graphicsview/elasticnodes/graphwidget.cpp</span> <!-- $$$graphicsview/elasticnodes/graphwidget.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 "graphwidget.h"</span> <span class="preprocessor">#include "edge.h"</span> <span class="preprocessor">#include "node.h"</span> <span class="preprocessor">#include <math.h></span> <span class="preprocessor">#include <QKeyEvent></span> <span class="preprocessor">#include <QRandomGenerator></span> GraphWidget<span class="operator">::</span>GraphWidget(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent) : <span class="type"><a href="qgraphicsview.html">QGraphicsView</a></span>(parent)<span class="operator">,</span> timerId(<span class="number">0</span>) { <span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span> <span class="operator">*</span>scene <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span>(<span class="keyword">this</span>); scene<span class="operator">-</span><span class="operator">></span>setItemIndexMethod(<span class="type"><a href="qgraphicsscene.html">QGraphicsScene</a></span><span class="operator">::</span>NoIndex); scene<span class="operator">-</span><span class="operator">></span>setSceneRect(<span class="operator">-</span><span class="number">200</span><span class="operator">,</span> <span class="operator">-</span><span class="number">200</span><span class="operator">,</span> <span class="number">400</span><span class="operator">,</span> <span class="number">400</span>); setScene(scene); setCacheMode(CacheBackground); setViewportUpdateMode(BoundingRectViewportUpdate); setRenderHint(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span><span class="operator">::</span>Antialiasing); setTransformationAnchor(AnchorUnderMouse); scale(<span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">0.8</span>)<span class="operator">,</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">0.8</span>)); setMinimumSize(<span class="number">400</span><span class="operator">,</span> <span class="number">400</span>); setWindowTitle(tr(<span class="string">"Elastic Nodes"</span>)); Node <span class="operator">*</span>node1 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>); Node <span class="operator">*</span>node2 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>); Node <span class="operator">*</span>node3 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>); Node <span class="operator">*</span>node4 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>); centerNode <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>); Node <span class="operator">*</span>node6 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>); Node <span class="operator">*</span>node7 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>); Node <span class="operator">*</span>node8 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>); Node <span class="operator">*</span>node9 <span class="operator">=</span> <span class="keyword">new</span> Node(<span class="keyword">this</span>); scene<span class="operator">-</span><span class="operator">></span>addItem(node1); scene<span class="operator">-</span><span class="operator">></span>addItem(node2); scene<span class="operator">-</span><span class="operator">></span>addItem(node3); scene<span class="operator">-</span><span class="operator">></span>addItem(node4); scene<span class="operator">-</span><span class="operator">></span>addItem(centerNode); scene<span class="operator">-</span><span class="operator">></span>addItem(node6); scene<span class="operator">-</span><span class="operator">></span>addItem(node7); scene<span class="operator">-</span><span class="operator">></span>addItem(node8); scene<span class="operator">-</span><span class="operator">></span>addItem(node9); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node1<span class="operator">,</span> node2)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node2<span class="operator">,</span> node3)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node2<span class="operator">,</span> centerNode)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node3<span class="operator">,</span> node6)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node4<span class="operator">,</span> node1)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node4<span class="operator">,</span> centerNode)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(centerNode<span class="operator">,</span> node6)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(centerNode<span class="operator">,</span> node8)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node6<span class="operator">,</span> node9)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node7<span class="operator">,</span> node4)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node8<span class="operator">,</span> node7)); scene<span class="operator">-</span><span class="operator">></span>addItem(<span class="keyword">new</span> Edge(node9<span class="operator">,</span> node8)); node1<span class="operator">-</span><span class="operator">></span>setPos(<span class="operator">-</span><span class="number">50</span><span class="operator">,</span> <span class="operator">-</span><span class="number">50</span>); node2<span class="operator">-</span><span class="operator">></span>setPos(<span class="number">0</span><span class="operator">,</span> <span class="operator">-</span><span class="number">50</span>); node3<span class="operator">-</span><span class="operator">></span>setPos(<span class="number">50</span><span class="operator">,</span> <span class="operator">-</span><span class="number">50</span>); node4<span class="operator">-</span><span class="operator">></span>setPos(<span class="operator">-</span><span class="number">50</span><span class="operator">,</span> <span class="number">0</span>); centerNode<span class="operator">-</span><span class="operator">></span>setPos(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span>); node6<span class="operator">-</span><span class="operator">></span>setPos(<span class="number">50</span><span class="operator">,</span> <span class="number">0</span>); node7<span class="operator">-</span><span class="operator">></span>setPos(<span class="operator">-</span><span class="number">50</span><span class="operator">,</span> <span class="number">50</span>); node8<span class="operator">-</span><span class="operator">></span>setPos(<span class="number">0</span><span class="operator">,</span> <span class="number">50</span>); node9<span class="operator">-</span><span class="operator">></span>setPos(<span class="number">50</span><span class="operator">,</span> <span class="number">50</span>); } <span class="type">void</span> GraphWidget<span class="operator">::</span>itemMoved() { <span class="keyword">if</span> (<span class="operator">!</span>timerId) timerId <span class="operator">=</span> startTimer(<span class="number">1000</span> <span class="operator">/</span> <span class="number">25</span>); } <span class="type">void</span> GraphWidget<span class="operator">::</span>keyPressEvent(<span class="type"><a href="../qtgui/qkeyevent.html">QKeyEvent</a></span> <span class="operator">*</span>event) { <span class="keyword">switch</span> (event<span class="operator">-</span><span class="operator">></span>key()) { <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Key_Up: centerNode<span class="operator">-</span><span class="operator">></span>moveBy(<span class="number">0</span><span class="operator">,</span> <span class="operator">-</span><span class="number">20</span>); <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Key_Down: centerNode<span class="operator">-</span><span class="operator">></span>moveBy(<span class="number">0</span><span class="operator">,</span> <span class="number">20</span>); <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Key_Left: centerNode<span class="operator">-</span><span class="operator">></span>moveBy(<span class="operator">-</span><span class="number">20</span><span class="operator">,</span> <span class="number">0</span>); <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Key_Right: centerNode<span class="operator">-</span><span class="operator">></span>moveBy(<span class="number">20</span><span class="operator">,</span> <span class="number">0</span>); <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Key_Plus: zoomIn(); <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Key_Minus: zoomOut(); <span class="keyword">break</span>; <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Key_Space: <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>Key_Enter: shuffle(); <span class="keyword">break</span>; <span class="keyword">default</span>: <span class="type"><a href="qgraphicsview.html">QGraphicsView</a></span><span class="operator">::</span>keyPressEvent(event); } } <span class="type">void</span> GraphWidget<span class="operator">::</span>timerEvent(<span class="type"><a href="../qtcore/qtimerevent.html">QTimerEvent</a></span> <span class="operator">*</span>event) { Q_UNUSED(event); <span class="type"><a href="../qtcore/qlist.html">QList</a></span><span class="operator"><</span>Node <span class="operator">*</span><span class="operator">></span> nodes; 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()) { <span class="keyword">if</span> (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)) nodes <span class="operator"><</span><span class="operator"><</span> node; } foreach (Node <span class="operator">*</span>node<span class="operator">,</span> nodes) node<span class="operator">-</span><span class="operator">></span>calculateForces(); bool itemsMoved <span class="operator">=</span> <span class="keyword">false</span>; foreach (Node <span class="operator">*</span>node<span class="operator">,</span> nodes) { <span class="keyword">if</span> (node<span class="operator">-</span><span class="operator">></span>advancePosition()) itemsMoved <span class="operator">=</span> <span class="keyword">true</span>; } <span class="keyword">if</span> (<span class="operator">!</span>itemsMoved) { killTimer(timerId); timerId <span class="operator">=</span> <span class="number">0</span>; } } <span class="preprocessor">#if QT_CONFIG(wheelevent)</span> <span class="type">void</span> GraphWidget<span class="operator">::</span>wheelEvent(<span class="type"><a href="../qtgui/qwheelevent.html">QWheelEvent</a></span> <span class="operator">*</span>event) { scaleView(pow((<span class="type">double</span>)<span class="number">2</span><span class="operator">,</span> <span class="operator">-</span>event<span class="operator">-</span><span class="operator">></span>delta() <span class="operator">/</span> <span class="number">240.0</span>)); } <span class="preprocessor">#endif</span> <span class="type">void</span> GraphWidget<span class="operator">::</span>drawBackground(<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="../qtcore/qrectf.html">QRectF</a></span> <span class="operator">&</span>rect) { Q_UNUSED(rect); <span class="comment">// Shadow</span> <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> sceneRect <span class="operator">=</span> <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>sceneRect(); <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> rightShadow(sceneRect<span class="operator">.</span>right()<span class="operator">,</span> sceneRect<span class="operator">.</span>top() <span class="operator">+</span> <span class="number">5</span><span class="operator">,</span> <span class="number">5</span><span class="operator">,</span> sceneRect<span class="operator">.</span>height()); <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> bottomShadow(sceneRect<span class="operator">.</span>left() <span class="operator">+</span> <span class="number">5</span><span class="operator">,</span> sceneRect<span class="operator">.</span>bottom()<span class="operator">,</span> sceneRect<span class="operator">.</span>width()<span class="operator">,</span> <span class="number">5</span>); <span class="keyword">if</span> (rightShadow<span class="operator">.</span>intersects(rect) <span class="operator">|</span><span class="operator">|</span> rightShadow<span class="operator">.</span>contains(rect)) painter<span class="operator">-</span><span class="operator">></span>fillRect(rightShadow<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>darkGray); <span class="keyword">if</span> (bottomShadow<span class="operator">.</span>intersects(rect) <span class="operator">|</span><span class="operator">|</span> bottomShadow<span class="operator">.</span>contains(rect)) painter<span class="operator">-</span><span class="operator">></span>fillRect(bottomShadow<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>darkGray); <span class="comment">// Fill</span> <span class="type"><a href="../qtgui/qlineargradient.html">QLinearGradient</a></span> gradient(sceneRect<span class="operator">.</span>topLeft()<span class="operator">,</span> sceneRect<span class="operator">.</span>bottomRight()); 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>white); 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>lightGray); painter<span class="operator">-</span><span class="operator">></span>fillRect(rect<span class="operator">.</span>intersected(sceneRect)<span class="operator">,</span> gradient); 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>NoBrush); painter<span class="operator">-</span><span class="operator">></span>drawRect(sceneRect); <span class="comment">// Text</span> <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> textRect(sceneRect<span class="operator">.</span>left() <span class="operator">+</span> <span class="number">4</span><span class="operator">,</span> sceneRect<span class="operator">.</span>top() <span class="operator">+</span> <span class="number">4</span><span class="operator">,</span> sceneRect<span class="operator">.</span>width() <span class="operator">-</span> <span class="number">4</span><span class="operator">,</span> sceneRect<span class="operator">.</span>height() <span class="operator">-</span> <span class="number">4</span>); <span class="type"><a href="../qtcore/qstring.html">QString</a></span> message(tr(<span class="string">"Click and drag the nodes around, and zoom with the mouse "</span> <span class="string">"wheel or the '+' and '-' keys"</span>)); <span class="type"><a href="../qtgui/qfont.html">QFont</a></span> font <span class="operator">=</span> painter<span class="operator">-</span><span class="operator">></span>font(); font<span class="operator">.</span>setBold(<span class="keyword">true</span>); font<span class="operator">.</span>setPointSize(<span class="number">14</span>); painter<span class="operator">-</span><span class="operator">></span>setFont(font); 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>lightGray); painter<span class="operator">-</span><span class="operator">></span>drawText(textRect<span class="operator">.</span>translated(<span class="number">2</span><span class="operator">,</span> <span class="number">2</span>)<span class="operator">,</span> message); 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>black); painter<span class="operator">-</span><span class="operator">></span>drawText(textRect<span class="operator">,</span> message); } <span class="type">void</span> GraphWidget<span class="operator">::</span>scaleView(<span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> scaleFactor) { <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> factor <span class="operator">=</span> transform()<span class="operator">.</span>scale(scaleFactor<span class="operator">,</span> scaleFactor)<span class="operator">.</span>mapRect(<span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span>(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="number">1</span>))<span class="operator">.</span>width(); <span class="keyword">if</span> (factor <span class="operator"><</span> <span class="number">0.07</span> <span class="operator">|</span><span class="operator">|</span> factor <span class="operator">></span> <span class="number">100</span>) <span class="keyword">return</span>; scale(scaleFactor<span class="operator">,</span> scaleFactor); } <span class="type">void</span> GraphWidget<span class="operator">::</span>shuffle() { 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()) { <span class="keyword">if</span> (qgraphicsitem_cast<span class="operator"><</span>Node <span class="operator">*</span><span class="operator">></span>(item)) item<span class="operator">-</span><span class="operator">></span>setPos(<span class="operator">-</span><span class="number">150</span> <span class="operator">+</span> <span class="type"><a href="../qtcore/qrandomgenerator.html">QRandomGenerator</a></span><span class="operator">::</span>global()<span class="operator">-</span><span class="operator">></span>bounded(<span class="number">300</span>)<span class="operator">,</span> <span class="operator">-</span><span class="number">150</span> <span class="operator">+</span> <span class="type"><a href="../qtcore/qrandomgenerator.html">QRandomGenerator</a></span><span class="operator">::</span>global()<span class="operator">-</span><span class="operator">></span>bounded(<span class="number">300</span>)); } } <span class="type">void</span> GraphWidget<span class="operator">::</span>zoomIn() { scaleView(<span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">1.2</span>)); } <span class="type">void</span> GraphWidget<span class="operator">::</span>zoomOut() { scaleView(<span class="number">1</span> <span class="operator">/</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span>(<span class="number">1.2</span>)); } </pre> </div> <!-- @@@graphicsview/elasticnodes/graphwidget.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>