<?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>paintarea.cpp Example File | 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-tools-plugandpaint-app-example.html">Plug & Paint Example</a></td><td >paintarea.cpp Example File</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right"><a href="qtwidgets-index.html">Qt 5.12.2 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">paintarea.cpp Example File</h1> <span class="subtitle">tools/plugandpaint/app/paintarea.cpp</span> <!-- $$$tools/plugandpaint/app/paintarea.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 "interfaces.h"</span> <span class="preprocessor">#include "paintarea.h"</span> <span class="preprocessor">#include <QMouseEvent></span> <span class="preprocessor">#include <QPainter></span> PaintArea<span class="operator">::</span>PaintArea(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent) : <span class="type"><a href="qwidget.html">QWidget</a></span>(parent) { setAttribute(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>WA_StaticContents); setAttribute(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>WA_NoBackground); theImage<span class="operator">.</span>fill(<a href="../qtgui/qcolor.html#qRgb">qRgb</a>(<span class="number">255</span><span class="operator">,</span> <span class="number">255</span><span class="operator">,</span> <span class="number">255</span>)); } bool PaintArea<span class="operator">::</span>openImage(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&</span>fileName) { <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> image; <span class="keyword">if</span> (<span class="operator">!</span>image<span class="operator">.</span>load(fileName)) <span class="keyword">return</span> <span class="keyword">false</span>; setImage(image); <span class="keyword">return</span> <span class="keyword">true</span>; } bool PaintArea<span class="operator">::</span>saveImage(<span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&</span>fileName<span class="operator">,</span> <span class="keyword">const</span> <span class="type">char</span> <span class="operator">*</span>fileFormat) { <span class="keyword">return</span> theImage<span class="operator">.</span>save(fileName<span class="operator">,</span> fileFormat); } <span class="type">void</span> PaintArea<span class="operator">::</span>setImage(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> <span class="operator">&</span>image) { theImage <span class="operator">=</span> image<span class="operator">.</span>convertToFormat(<span class="type"><a href="../qtgui/qimage.html">QImage</a></span><span class="operator">::</span>Format_RGB32); update(); updateGeometry(); } <span class="type">void</span> PaintArea<span class="operator">::</span>insertShape(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span> <span class="operator">&</span>path) { pendingPath <span class="operator">=</span> path; <span class="preprocessor">#ifndef QT_NO_CURSOR</span> setCursor(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>CrossCursor); <span class="preprocessor">#endif</span> } <span class="type">void</span> PaintArea<span class="operator">::</span>setBrushColor(<span class="keyword">const</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span> <span class="operator">&</span>color) { <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>color <span class="operator">=</span> color; } <span class="type">void</span> PaintArea<span class="operator">::</span>setBrushWidth(<span class="type">int</span> width) { thickness <span class="operator">=</span> width; } <span class="type">void</span> PaintArea<span class="operator">::</span>setBrush(BrushInterface <span class="operator">*</span>brushInterface<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="../qtcore/qstring.html">QString</a></span> <span class="operator">&</span>brush) { <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>brushInterface <span class="operator">=</span> brushInterface; <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>brush <span class="operator">=</span> brush; } <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> PaintArea<span class="operator">::</span>sizeHint() <span class="keyword">const</span> { <span class="keyword">return</span> theImage<span class="operator">.</span>size(); } <span class="type">void</span> PaintArea<span class="operator">::</span>paintEvent(<span class="type"><a href="../qtgui/qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span> <span class="comment">/* event */</span>) { <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="keyword">this</span>); painter<span class="operator">.</span>drawImage(<span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span>)<span class="operator">,</span> theImage); } <span class="type">void</span> PaintArea<span class="operator">::</span>mousePressEvent(<span class="type"><a href="../qtgui/qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event) { <span class="keyword">if</span> (event<span class="operator">-</span><span class="operator">></span>button() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>LeftButton) { <span class="keyword">if</span> (<span class="operator">!</span>pendingPath<span class="operator">.</span>isEmpty()) { <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&</span>theImage); setupPainter(painter); <span class="keyword">const</span> <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> boundingRect <span class="operator">=</span> pendingPath<span class="operator">.</span>boundingRect(); <span class="type"><a href="../qtgui/qlineargradient.html">QLinearGradient</a></span> gradient(boundingRect<span class="operator">.</span>topRight()<span class="operator">,</span> boundingRect<span class="operator">.</span>bottomLeft()); gradient<span class="operator">.</span>setColorAt(<span class="number">0.0</span><span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(color<span class="operator">.</span>red()<span class="operator">,</span> color<span class="operator">.</span>green()<span class="operator">,</span> color<span class="operator">.</span>blue()<span class="operator">,</span> <span class="number">63</span>)); gradient<span class="operator">.</span>setColorAt(<span class="number">1.0</span><span class="operator">,</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(color<span class="operator">.</span>red()<span class="operator">,</span> color<span class="operator">.</span>green()<span class="operator">,</span> color<span class="operator">.</span>blue()<span class="operator">,</span> <span class="number">191</span>)); painter<span class="operator">.</span>setBrush(gradient); painter<span class="operator">.</span>translate(event<span class="operator">-</span><span class="operator">></span>pos() <span class="operator">-</span> boundingRect<span class="operator">.</span>center()); painter<span class="operator">.</span>drawPath(pendingPath); pendingPath <span class="operator">=</span> <span class="type"><a href="../qtgui/qpainterpath.html">QPainterPath</a></span>(); <span class="preprocessor">#ifndef QT_NO_CURSOR</span> unsetCursor(); <span class="preprocessor">#endif</span> update(); } <span class="keyword">else</span> { <span class="keyword">if</span> (brushInterface) { <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&</span>theImage); setupPainter(painter); <span class="keyword">const</span> <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect <span class="operator">=</span> brushInterface<span class="operator">-</span><span class="operator">></span>mousePress(brush<span class="operator">,</span> painter<span class="operator">,</span> event<span class="operator">-</span><span class="operator">></span>pos()); update(rect); } lastPos <span class="operator">=</span> event<span class="operator">-</span><span class="operator">></span>pos(); } } } <span class="type">void</span> PaintArea<span class="operator">::</span>mouseMoveEvent(<span class="type"><a href="../qtgui/qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event) { <span class="keyword">if</span> ((event<span class="operator">-</span><span class="operator">></span>buttons() <span class="operator">&</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>LeftButton) <span class="operator">&</span><span class="operator">&</span> lastPos <span class="operator">!</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">1</span>)) { <span class="keyword">if</span> (brushInterface) { <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&</span>theImage); setupPainter(painter); <span class="keyword">const</span> <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect <span class="operator">=</span> brushInterface<span class="operator">-</span><span class="operator">></span>mouseMove(brush<span class="operator">,</span> painter<span class="operator">,</span> lastPos<span class="operator">,</span> event<span class="operator">-</span><span class="operator">></span>pos()); update(rect); } lastPos <span class="operator">=</span> event<span class="operator">-</span><span class="operator">></span>pos(); } } <span class="type">void</span> PaintArea<span class="operator">::</span>mouseReleaseEvent(<span class="type"><a href="../qtgui/qmouseevent.html">QMouseEvent</a></span> <span class="operator">*</span>event) { <span class="keyword">if</span> (event<span class="operator">-</span><span class="operator">></span>button() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>LeftButton <span class="operator">&</span><span class="operator">&</span> lastPos <span class="operator">!</span><span class="operator">=</span> <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">1</span>)) { <span class="keyword">if</span> (brushInterface) { <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&</span>theImage); setupPainter(painter); <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect <span class="operator">=</span> brushInterface<span class="operator">-</span><span class="operator">></span>mouseRelease(brush<span class="operator">,</span> painter<span class="operator">,</span> event<span class="operator">-</span><span class="operator">></span>pos()); update(rect); } lastPos <span class="operator">=</span> <span class="type"><a href="../qtcore/qpoint.html">QPoint</a></span>(<span class="operator">-</span><span class="number">1</span><span class="operator">,</span> <span class="operator">-</span><span class="number">1</span>); } } <span class="type">void</span> PaintArea<span class="operator">::</span>setupPainter(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> <span class="operator">&</span>painter) { painter<span class="operator">.</span>setRenderHint(<span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span><span class="operator">::</span>Antialiasing<span class="operator">,</span> <span class="keyword">true</span>); painter<span class="operator">.</span>setPen(<span class="type"><a href="../qtgui/qpen.html">QPen</a></span>(color<span class="operator">,</span> thickness<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)); } </pre> </div> <!-- @@@tools/plugandpaint/app/paintarea.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>