<?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>arrow.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-diagramscene-example.html">Diagram Scene Example</a></td><td >arrow.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">arrow.cpp Example File</h1> <span class="subtitle">graphicsview/diagramscene/arrow.cpp</span> <!-- $$$graphicsview/diagramscene/arrow.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 "arrow.h"</span> <span class="preprocessor">#include <qmath.h></span> <span class="preprocessor">#include <QPen></span> <span class="preprocessor">#include <QPainter></span> Arrow<span class="operator">::</span>Arrow(DiagramItem <span class="operator">*</span>startItem<span class="operator">,</span> DiagramItem <span class="operator">*</span>endItem<span class="operator">,</span> <span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span> <span class="operator">*</span>parent) : <span class="type"><a href="qgraphicslineitem.html">QGraphicsLineItem</a></span>(parent) { myStartItem <span class="operator">=</span> startItem; myEndItem <span class="operator">=</span> endItem; setFlag(<span class="type"><a href="qgraphicsitem.html">QGraphicsItem</a></span><span class="operator">::</span>ItemIsSelectable<span class="operator">,</span> <span class="keyword">true</span>); myColor <span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>black; setPen(<span class="type"><a href="../qtgui/qpen.html">QPen</a></span>(myColor<span class="operator">,</span> <span class="number">2</span><span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>SolidLine<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>RoundCap<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>RoundJoin)); } <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> Arrow<span class="operator">::</span>boundingRect() <span class="keyword">const</span> { <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> extra <span class="operator">=</span> (pen()<span class="operator">.</span>width() <span class="operator">+</span> <span class="number">20</span>) <span class="operator">/</span> <span class="number">2.0</span>; <span class="keyword">return</span> <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span>(line()<span class="operator">.</span>p1()<span class="operator">,</span> <span class="type"><a href="../qtcore/qsizef.html">QSizeF</a></span>(line()<span class="operator">.</span>p2()<span class="operator">.</span>x() <span class="operator">-</span> line()<span class="operator">.</span>p1()<span class="operator">.</span>x()<span class="operator">,</span> line()<span class="operator">.</span>p2()<span class="operator">.</span>y() <span class="operator">-</span> line()<span class="operator">.</span>p1()<span class="operator">.</span>y())) <span class="operator">.</span>normalized() <span class="operator">.</span>adjusted(<span class="operator">-</span>extra<span class="operator">,</span> <span class="operator">-</span>extra<span class="operator">,</span> extra<span class="operator">,</span> extra); } <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> Arrow<span class="operator">::</span>shape() <span class="keyword">const</span> { <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> path <span class="operator">=</span> <span class="type"><a href="qgraphicslineitem.html">QGraphicsLineItem</a></span><span class="operator">::</span>shape(); path<span class="operator">.</span>addPolygon(arrowHead); <span class="keyword">return</span> path; } <span class="type">void</span> Arrow<span class="operator">::</span>updatePosition() { <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span> line(mapFromItem(myStartItem<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span>)<span class="operator">,</span> mapFromItem(myEndItem<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> <span class="number">0</span>)); setLine(line); } <span class="type">void</span> Arrow<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><span class="operator">,</span> <span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>) { <span class="keyword">if</span> (myStartItem<span class="operator">-</span><span class="operator">></span>collidesWithItem(myEndItem)) <span class="keyword">return</span>; <span class="type"><a href="../qtgui/qpen.html">QPen</a></span> myPen <span class="operator">=</span> pen(); myPen<span class="operator">.</span>setColor(myColor); <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> arrowSize <span class="operator">=</span> <span class="number">20</span>; painter<span class="operator">-</span><span class="operator">></span>setPen(myPen); painter<span class="operator">-</span><span class="operator">></span>setBrush(myColor); <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span> centerLine(myStartItem<span class="operator">-</span><span class="operator">></span>pos()<span class="operator">,</span> myEndItem<span class="operator">-</span><span class="operator">></span>pos()); <span class="type"><a href="../qtgui/qpolygonf.html">QPolygonF</a></span> endPolygon <span class="operator">=</span> myEndItem<span class="operator">-</span><span class="operator">></span>polygon(); <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span> p1 <span class="operator">=</span> endPolygon<span class="operator">.</span>first() <span class="operator">+</span> myEndItem<span class="operator">-</span><span class="operator">></span>pos(); <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span> p2; <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span> intersectPoint; <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span> polyLine; <span class="keyword">for</span> (<span class="type">int</span> i <span class="operator">=</span> <span class="number">1</span>; i <span class="operator"><</span> endPolygon<span class="operator">.</span>count(); <span class="operator">+</span><span class="operator">+</span>i) { p2 <span class="operator">=</span> endPolygon<span class="operator">.</span>at(i) <span class="operator">+</span> myEndItem<span class="operator">-</span><span class="operator">></span>pos(); polyLine <span class="operator">=</span> <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span>(p1<span class="operator">,</span> p2); <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span><span class="operator">::</span>IntersectType intersectType <span class="operator">=</span> polyLine<span class="operator">.</span>intersect(centerLine<span class="operator">,</span> <span class="operator">&</span>intersectPoint); <span class="keyword">if</span> (intersectType <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span><span class="operator">::</span>BoundedIntersection) <span class="keyword">break</span>; p1 <span class="operator">=</span> p2; } setLine(<span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span>(intersectPoint<span class="operator">,</span> myStartItem<span class="operator">-</span><span class="operator">></span>pos())); <span class="type">double</span> angle <span class="operator">=</span> std<span class="operator">::</span>atan2(<span class="operator">-</span>line()<span class="operator">.</span>dy()<span class="operator">,</span> line()<span class="operator">.</span>dx()); <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span> arrowP1 <span class="operator">=</span> line()<span class="operator">.</span>p1() <span class="operator">+</span> <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span>(sin(angle <span class="operator">+</span> M_PI <span class="operator">/</span> <span class="number">3</span>) <span class="operator">*</span> arrowSize<span class="operator">,</span> cos(angle <span class="operator">+</span> M_PI <span class="operator">/</span> <span class="number">3</span>) <span class="operator">*</span> arrowSize); <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span> arrowP2 <span class="operator">=</span> line()<span class="operator">.</span>p1() <span class="operator">+</span> <span class="type"><a href="../qtcore/qpointf.html">QPointF</a></span>(sin(angle <span class="operator">+</span> M_PI <span class="operator">-</span> M_PI <span class="operator">/</span> <span class="number">3</span>) <span class="operator">*</span> arrowSize<span class="operator">,</span> cos(angle <span class="operator">+</span> M_PI <span class="operator">-</span> M_PI <span class="operator">/</span> <span class="number">3</span>) <span class="operator">*</span> arrowSize); arrowHead<span class="operator">.</span>clear(); arrowHead <span class="operator"><</span><span class="operator"><</span> line()<span class="operator">.</span>p1() <span class="operator"><</span><span class="operator"><</span> arrowP1 <span class="operator"><</span><span class="operator"><</span> arrowP2; painter<span class="operator">-</span><span class="operator">></span>drawLine(line()); painter<span class="operator">-</span><span class="operator">></span>drawPolygon(arrowHead); <span class="keyword">if</span> (isSelected()) { painter<span class="operator">-</span><span class="operator">></span>setPen(<span class="type"><a href="../qtgui/qpen.html">QPen</a></span>(myColor<span class="operator">,</span> <span class="number">1</span><span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>DashLine)); <span class="type"><a href="../qtcore/qlinef.html">QLineF</a></span> myLine <span class="operator">=</span> line(); myLine<span class="operator">.</span>translate(<span class="number">0</span><span class="operator">,</span> <span class="number">4.0</span>); painter<span class="operator">-</span><span class="operator">></span>drawLine(myLine); myLine<span class="operator">.</span>translate(<span class="number">0</span><span class="operator">,</span><span class="operator">-</span><span class="number">8.0</span>); painter<span class="operator">-</span><span class="operator">></span>drawLine(myLine); } } </pre> </div> <!-- @@@graphicsview/diagramscene/arrow.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>