<?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>scribblearea.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-touch-fingerpaint-example.html">Finger Paint Example</a></td><td >scribblearea.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">scribblearea.cpp Example File</h1> <span class="subtitle">touch/fingerpaint/scribblearea.cpp</span> <!-- $$$touch/fingerpaint/scribblearea.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 <QtWidgets></span> <span class="preprocessor">#if defined(QT_PRINTSUPPORT_LIB)</span> <span class="preprocessor">#include <QtPrintSupport/qtprintsupportglobal.h></span> <span class="preprocessor">#if QT_CONFIG(printdialog)</span> <span class="preprocessor">#include <QPrinter></span> <span class="preprocessor">#include <QPrintDialog></span> <span class="preprocessor">#endif</span> <span class="preprocessor">#endif</span> <span class="preprocessor">#include "scribblearea.h"</span> <span class="keyword">static</span> <span class="keyword">const</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> MinimumDiameter <span class="operator">=</span> <span class="number">3.0</span>; <span class="keyword">static</span> <span class="keyword">const</span> <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> MaximumDiameter <span class="operator">=</span> <span class="number">50.0</span>; ScribbleArea<span class="operator">::</span>ScribbleArea(<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_AcceptTouchEvents); setAttribute(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>WA_StaticContents); modified <span class="operator">=</span> <span class="keyword">false</span>; myPenColors <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"green"</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"purple"</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"red"</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"blue"</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"yellow"</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"pink"</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"orange"</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"brown"</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"grey"</span>) <span class="operator"><</span><span class="operator"><</span> <span class="type"><a href="../qtgui/qcolor.html">QColor</a></span>(<span class="string">"black"</span>); } bool ScribbleArea<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> loadedImage; <span class="keyword">if</span> (<span class="operator">!</span>loadedImage<span class="operator">.</span>load(fileName)) <span class="keyword">return</span> <span class="keyword">false</span>; <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> newSize <span class="operator">=</span> loadedImage<span class="operator">.</span>size()<span class="operator">.</span>expandedTo(size()); resizeImage(<span class="operator">&</span>loadedImage<span class="operator">,</span> newSize); image <span class="operator">=</span> loadedImage; modified <span class="operator">=</span> <span class="keyword">false</span>; update(); <span class="keyword">return</span> <span class="keyword">true</span>; } bool ScribbleArea<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="type"><a href="../qtgui/qimage.html">QImage</a></span> visibleImage <span class="operator">=</span> image; resizeImage(<span class="operator">&</span>visibleImage<span class="operator">,</span> size()); <span class="keyword">if</span> (visibleImage<span class="operator">.</span>save(fileName<span class="operator">,</span> fileFormat)) { modified <span class="operator">=</span> <span class="keyword">false</span>; <span class="keyword">return</span> <span class="keyword">true</span>; } <span class="keyword">else</span> { <span class="keyword">return</span> <span class="keyword">false</span>; } } <span class="type">void</span> ScribbleArea<span class="operator">::</span>clearImage() { image<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>)); modified <span class="operator">=</span> <span class="keyword">true</span>; update(); } <span class="type">void</span> ScribbleArea<span class="operator">::</span>paintEvent(<span class="type"><a href="../qtgui/qpaintevent.html">QPaintEvent</a></span> <span class="operator">*</span>event) { <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="keyword">this</span>); <span class="keyword">const</span> <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect <span class="operator">=</span> event<span class="operator">-</span><span class="operator">></span>rect(); painter<span class="operator">.</span>drawImage(rect<span class="operator">.</span>topLeft()<span class="operator">,</span> image<span class="operator">,</span> rect); } <span class="type">void</span> ScribbleArea<span class="operator">::</span>resizeEvent(<span class="type"><a href="../qtgui/qresizeevent.html">QResizeEvent</a></span> <span class="operator">*</span>event) { <span class="keyword">if</span> (width() <span class="operator">></span> image<span class="operator">.</span>width() <span class="operator">|</span><span class="operator">|</span> height() <span class="operator">></span> image<span class="operator">.</span>height()) { <span class="type">int</span> newWidth <span class="operator">=</span> <a href="../qtcore/qtglobal.html#qMax">qMax</a>(width() <span class="operator">+</span> <span class="number">128</span><span class="operator">,</span> image<span class="operator">.</span>width()); <span class="type">int</span> newHeight <span class="operator">=</span> <a href="../qtcore/qtglobal.html#qMax">qMax</a>(height() <span class="operator">+</span> <span class="number">128</span><span class="operator">,</span> image<span class="operator">.</span>height()); resizeImage(<span class="operator">&</span>image<span class="operator">,</span> <span class="type"><a href="../qtcore/qsize.html">QSize</a></span>(newWidth<span class="operator">,</span> newHeight)); update(); } <span class="type"><a href="qwidget.html">QWidget</a></span><span class="operator">::</span>resizeEvent(event); } <span class="type">void</span> ScribbleArea<span class="operator">::</span>resizeImage(<span class="type"><a href="../qtgui/qimage.html">QImage</a></span> <span class="operator">*</span>image<span class="operator">,</span> <span class="keyword">const</span> <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> <span class="operator">&</span>newSize) { <span class="keyword">if</span> (image<span class="operator">-</span><span class="operator">></span>size() <span class="operator">=</span><span class="operator">=</span> newSize) <span class="keyword">return</span>; <span class="type"><a href="../qtgui/qimage.html">QImage</a></span> newImage(newSize<span class="operator">,</span> <span class="type"><a href="../qtgui/qimage.html">QImage</a></span><span class="operator">::</span>Format_RGB32); newImage<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>)); <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&</span>newImage); 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> <span class="operator">*</span>image); <span class="operator">*</span>image <span class="operator">=</span> newImage; } <span class="type">void</span> ScribbleArea<span class="operator">::</span>print() { <span class="preprocessor">#if QT_CONFIG(printdialog)</span> <span class="type">QPrinter</span> printer(<span class="type">QPrinter</span><span class="operator">::</span>HighResolution); <span class="type">QPrintDialog</span> printDialog(<span class="operator">&</span>printer<span class="operator">,</span> <span class="keyword">this</span>); <span class="keyword">if</span> (printDialog<span class="operator">.</span>exec() <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qdialog.html">QDialog</a></span><span class="operator">::</span>Accepted) { <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&</span>printer); <span class="type"><a href="../qtcore/qrect.html">QRect</a></span> rect <span class="operator">=</span> painter<span class="operator">.</span>viewport(); <span class="type"><a href="../qtcore/qsize.html">QSize</a></span> size <span class="operator">=</span> image<span class="operator">.</span>size(); size<span class="operator">.</span>scale(rect<span class="operator">.</span>size()<span class="operator">,</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>KeepAspectRatio); painter<span class="operator">.</span>setViewport(rect<span class="operator">.</span>x()<span class="operator">,</span> rect<span class="operator">.</span>y()<span class="operator">,</span> size<span class="operator">.</span>width()<span class="operator">,</span> size<span class="operator">.</span>height()); painter<span class="operator">.</span>setWindow(image<span class="operator">.</span>rect()); painter<span class="operator">.</span>drawImage(<span class="number">0</span><span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> image); } <span class="preprocessor">#endif // QT_CONFIG(printdialog)</span> } bool ScribbleArea<span class="operator">::</span>event(<span class="type"><a href="../qtcore/qevent.html">QEvent</a></span> <span class="operator">*</span>event) { <span class="keyword">switch</span> (event<span class="operator">-</span><span class="operator">></span>type()) { <span class="keyword">case</span> <span class="type"><a href="../qtcore/qevent.html">QEvent</a></span><span class="operator">::</span>TouchBegin: <span class="keyword">case</span> <span class="type"><a href="../qtcore/qevent.html">QEvent</a></span><span class="operator">::</span>TouchUpdate: <span class="keyword">case</span> <span class="type"><a href="../qtcore/qevent.html">QEvent</a></span><span class="operator">::</span>TouchEnd: { <span class="type"><a href="../qtgui/qtouchevent.html">QTouchEvent</a></span> <span class="operator">*</span>touch <span class="operator">=</span> <span class="keyword">static_cast</span><span class="operator"><</span><span class="type"><a href="../qtgui/qtouchevent.html">QTouchEvent</a></span> <span class="operator">*</span><span class="operator">></span>(event); <span class="type"><a href="../qtcore/qlist.html">QList</a></span><span class="operator"><</span><span class="type"><a href="../qtgui/qtouchevent.html">QTouchEvent</a></span><span class="operator">::</span>TouchPoint<span class="operator">></span> touchPoints <span class="operator">=</span> <span class="keyword">static_cast</span><span class="operator"><</span><span class="type"><a href="../qtgui/qtouchevent.html">QTouchEvent</a></span> <span class="operator">*</span><span class="operator">></span>(event)<span class="operator">-</span><span class="operator">></span>touchPoints(); foreach (<span class="keyword">const</span> <span class="type"><a href="../qtgui/qtouchevent.html">QTouchEvent</a></span><span class="operator">::</span>TouchPoint <span class="operator">&</span>touchPoint<span class="operator">,</span> touchPoints) { <span class="keyword">switch</span> (touchPoint<span class="operator">.</span>state()) { <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>TouchPointStationary: <span class="keyword">case</span> <span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>TouchPointReleased: <span class="comment">// don't do anything if this touch point hasn't moved or has been released</span> <span class="keyword">continue</span>; <span class="keyword">default</span>: { <span class="type"><a href="../qtcore/qrectf.html">QRectF</a></span> rect <span class="operator">=</span> touchPoint<span class="operator">.</span>rect(); <span class="keyword">if</span> (rect<span class="operator">.</span>isEmpty()) { <span class="type"><a href="../qtcore/qtglobal.html#qreal-typedef">qreal</a></span> diameter <span class="operator">=</span> MaximumDiameter; <span class="keyword">if</span> (touch<span class="operator">-</span><span class="operator">></span>device()<span class="operator">-</span><span class="operator">></span>capabilities() <span class="operator">&</span> <span class="type"><a href="../qtgui/qtouchdevice.html">QTouchDevice</a></span><span class="operator">::</span>Pressure) diameter <span class="operator">=</span> MinimumDiameter <span class="operator">+</span> (MaximumDiameter <span class="operator">-</span> MinimumDiameter) <span class="operator">*</span> touchPoint<span class="operator">.</span>pressure(); rect<span class="operator">.</span>setSize(<span class="type"><a href="../qtcore/qsizef.html">QSizeF</a></span>(diameter<span class="operator">,</span> diameter)); } <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter(<span class="operator">&</span>image); painter<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>setBrush(myPenColors<span class="operator">.</span>at(touchPoint<span class="operator">.</span>id() <span class="operator">%</span> myPenColors<span class="operator">.</span>count())); painter<span class="operator">.</span>drawEllipse(rect); painter<span class="operator">.</span>end(); modified <span class="operator">=</span> <span class="keyword">true</span>; <span class="type">int</span> rad <span class="operator">=</span> <span class="number">2</span>; update(rect<span class="operator">.</span>toRect()<span class="operator">.</span>adjusted(<span class="operator">-</span>rad<span class="operator">,</span><span class="operator">-</span>rad<span class="operator">,</span> <span class="operator">+</span>rad<span class="operator">,</span> <span class="operator">+</span>rad)); } <span class="keyword">break</span>; } } <span class="keyword">break</span>; } <span class="keyword">default</span>: <span class="keyword">return</span> <span class="type"><a href="qwidget.html">QWidget</a></span><span class="operator">::</span>event(event); } <span class="keyword">return</span> <span class="keyword">true</span>; } </pre> </div> <!-- @@@touch/fingerpaint/scribblearea.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>