<?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>mainwindow.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-itemviews-pixelator-example.html">Pixelator Example</a></td><td >mainwindow.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">mainwindow.cpp Example File</h1> <span class="subtitle">itemviews/pixelator/mainwindow.cpp</span> <!-- $$$itemviews/pixelator/mainwindow.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 "imagemodel.h"</span> <span class="preprocessor">#include "mainwindow.h"</span> <span class="preprocessor">#include "pixeldelegate.h"</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> MainWindow<span class="operator">::</span>MainWindow() { currentPath <span class="operator">=</span> <span class="type"><a href="../qtcore/qdir.html">QDir</a></span><span class="operator">::</span>homePath(); model <span class="operator">=</span> <span class="keyword">new</span> ImageModel(<span class="keyword">this</span>); <span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>centralWidget <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qwidget.html">QWidget</a></span>; view <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qtableview.html">QTableView</a></span>; view<span class="operator">-</span><span class="operator">></span>setShowGrid(<span class="keyword">false</span>); view<span class="operator">-</span><span class="operator">></span>horizontalHeader()<span class="operator">-</span><span class="operator">></span>hide(); view<span class="operator">-</span><span class="operator">></span>verticalHeader()<span class="operator">-</span><span class="operator">></span>hide(); view<span class="operator">-</span><span class="operator">></span>horizontalHeader()<span class="operator">-</span><span class="operator">></span>setMinimumSectionSize(<span class="number">1</span>); view<span class="operator">-</span><span class="operator">></span>verticalHeader()<span class="operator">-</span><span class="operator">></span>setMinimumSectionSize(<span class="number">1</span>); view<span class="operator">-</span><span class="operator">></span>setModel(model); PixelDelegate <span class="operator">*</span>delegate <span class="operator">=</span> <span class="keyword">new</span> PixelDelegate(<span class="keyword">this</span>); view<span class="operator">-</span><span class="operator">></span>setItemDelegate(delegate); <span class="type"><a href="qlabel.html">QLabel</a></span> <span class="operator">*</span>pixelSizeLabel <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qlabel.html">QLabel</a></span>(tr(<span class="string">"Pixel size:"</span>)); <span class="type"><a href="qspinbox.html">QSpinBox</a></span> <span class="operator">*</span>pixelSizeSpinBox <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qspinbox.html">QSpinBox</a></span>; pixelSizeSpinBox<span class="operator">-</span><span class="operator">></span>setMinimum(<span class="number">4</span>); pixelSizeSpinBox<span class="operator">-</span><span class="operator">></span>setMaximum(<span class="number">32</span>); pixelSizeSpinBox<span class="operator">-</span><span class="operator">></span>setValue(<span class="number">12</span>); <span class="type"><a href="qmenu.html">QMenu</a></span> <span class="operator">*</span>fileMenu <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qmenu.html">QMenu</a></span>(tr(<span class="string">"&File"</span>)<span class="operator">,</span> <span class="keyword">this</span>); <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>openAction <span class="operator">=</span> fileMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&Open..."</span>)); openAction<span class="operator">-</span><span class="operator">></span>setShortcuts(<span class="type"><a href="../qtgui/qkeysequence.html">QKeySequence</a></span><span class="operator">::</span>Open); printAction <span class="operator">=</span> fileMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&Print..."</span>)); printAction<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); printAction<span class="operator">-</span><span class="operator">></span>setShortcut(<span class="type"><a href="../qtgui/qkeysequence.html">QKeySequence</a></span><span class="operator">::</span>Print); <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>quitAction <span class="operator">=</span> fileMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"E&xit"</span>)); quitAction<span class="operator">-</span><span class="operator">></span>setShortcuts(<span class="type"><a href="../qtgui/qkeysequence.html">QKeySequence</a></span><span class="operator">::</span>Quit); <span class="type"><a href="qmenu.html">QMenu</a></span> <span class="operator">*</span>helpMenu <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qmenu.html">QMenu</a></span>(tr(<span class="string">"&Help"</span>)<span class="operator">,</span> <span class="keyword">this</span>); <span class="type"><a href="qaction.html">QAction</a></span> <span class="operator">*</span>aboutAction <span class="operator">=</span> helpMenu<span class="operator">-</span><span class="operator">></span>addAction(tr(<span class="string">"&About"</span>)); menuBar()<span class="operator">-</span><span class="operator">></span>addMenu(fileMenu); menuBar()<span class="operator">-</span><span class="operator">></span>addSeparator(); menuBar()<span class="operator">-</span><span class="operator">></span>addMenu(helpMenu); connect(openAction<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qaction.html">QAction</a></span><span class="operator">::</span>triggered<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>MainWindow<span class="operator">::</span>chooseImage); connect(printAction<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qaction.html">QAction</a></span><span class="operator">::</span>triggered<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>MainWindow<span class="operator">::</span>printImage); connect(quitAction<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qaction.html">QAction</a></span><span class="operator">::</span>triggered<span class="operator">,</span> <a href="qapplication.html#qApp">qApp</a><span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="../qtcore/qcoreapplication.html">QCoreApplication</a></span><span class="operator">::</span>quit); connect(aboutAction<span class="operator">,</span> <span class="operator">&</span><span class="type"><a href="qaction.html">QAction</a></span><span class="operator">::</span>triggered<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>MainWindow<span class="operator">::</span>showAboutBox); connect(pixelSizeSpinBox<span class="operator">,</span> <span class="type">QOverload</span><span class="operator"><</span><span class="type">int</span><span class="operator">></span><span class="operator">::</span>of(<span class="operator">&</span><span class="type"><a href="qspinbox.html">QSpinBox</a></span><span class="operator">::</span>valueChanged)<span class="operator">,</span> delegate<span class="operator">,</span> <span class="operator">&</span>PixelDelegate<span class="operator">::</span>setPixelSize); connect(pixelSizeSpinBox<span class="operator">,</span> <span class="type">QOverload</span><span class="operator"><</span><span class="type">int</span><span class="operator">></span><span class="operator">::</span>of(<span class="operator">&</span><span class="type"><a href="qspinbox.html">QSpinBox</a></span><span class="operator">::</span>valueChanged)<span class="operator">,</span> <span class="keyword">this</span><span class="operator">,</span> <span class="operator">&</span>MainWindow<span class="operator">::</span>updateView); <span class="type"><a href="qhboxlayout.html">QHBoxLayout</a></span> <span class="operator">*</span>controlsLayout <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qhboxlayout.html">QHBoxLayout</a></span>; controlsLayout<span class="operator">-</span><span class="operator">></span>addWidget(pixelSizeLabel); controlsLayout<span class="operator">-</span><span class="operator">></span>addWidget(pixelSizeSpinBox); controlsLayout<span class="operator">-</span><span class="operator">></span>addStretch(<span class="number">1</span>); <span class="type"><a href="qvboxlayout.html">QVBoxLayout</a></span> <span class="operator">*</span>mainLayout <span class="operator">=</span> <span class="keyword">new</span> <span class="type"><a href="qvboxlayout.html">QVBoxLayout</a></span>; mainLayout<span class="operator">-</span><span class="operator">></span>addWidget(view); mainLayout<span class="operator">-</span><span class="operator">></span>addLayout(controlsLayout); centralWidget<span class="operator">-</span><span class="operator">></span>setLayout(mainLayout); setCentralWidget(centralWidget); setWindowTitle(tr(<span class="string">"Pixelator"</span>)); resize(<span class="number">640</span><span class="operator">,</span> <span class="number">480</span>); } <span class="type">void</span> MainWindow<span class="operator">::</span>chooseImage() { <span class="type"><a href="../qtcore/qstring.html">QString</a></span> fileName <span class="operator">=</span> <span class="type"><a href="qfiledialog.html">QFileDialog</a></span><span class="operator">::</span>getOpenFileName(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">"Choose an image"</span>)<span class="operator">,</span> currentPath<span class="operator">,</span> <span class="string">"*"</span>); <span class="keyword">if</span> (<span class="operator">!</span>fileName<span class="operator">.</span>isEmpty()) openImage(fileName); } <span class="type">void</span> MainWindow<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> (image<span class="operator">.</span>load(fileName)) { model<span class="operator">-</span><span class="operator">></span>setImage(image); <span class="keyword">if</span> (<span class="operator">!</span>fileName<span class="operator">.</span>startsWith(<span class="string">":/"</span>)) { currentPath <span class="operator">=</span> fileName; setWindowTitle(tr(<span class="string">"%1 - Pixelator"</span>)<span class="operator">.</span>arg(currentPath)); } printAction<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">true</span>); updateView(); } } <span class="type">void</span> MainWindow<span class="operator">::</span>printImage() { <span class="preprocessor">#if QT_CONFIG(printdialog)</span> <span class="keyword">if</span> (model<span class="operator">-</span><span class="operator">></span>rowCount(<span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span>())<span class="operator">*</span>model<span class="operator">-</span><span class="operator">></span>columnCount(<span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span>()) <span class="operator">></span> <span class="number">90000</span>) { <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>StandardButton answer; answer <span class="operator">=</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>question(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">"Large Image Size"</span>)<span class="operator">,</span> tr(<span class="string">"The printed image may be very large. Are you sure that "</span> <span class="string">"you want to print it?"</span>)<span class="operator">,</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>Yes <span class="operator">|</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>No); <span class="keyword">if</span> (answer <span class="operator">=</span><span class="operator">=</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>No) <span class="keyword">return</span>; } <span class="type">QPrinter</span> printer(<span class="type">QPrinter</span><span class="operator">::</span>HighResolution); <span class="type">QPrintDialog</span> dlg(<span class="operator">&</span>printer<span class="operator">,</span> <span class="keyword">this</span>); dlg<span class="operator">.</span>setWindowTitle(tr(<span class="string">"Print Image"</span>)); <span class="keyword">if</span> (dlg<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="keyword">return</span>; } <span class="type"><a href="../qtgui/qpainter.html">QPainter</a></span> painter; painter<span class="operator">.</span>begin(<span class="operator">&</span>printer); <span class="type">int</span> rows <span class="operator">=</span> model<span class="operator">-</span><span class="operator">></span>rowCount(<span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span>()); <span class="type">int</span> columns <span class="operator">=</span> model<span class="operator">-</span><span class="operator">></span>columnCount(<span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span>()); <span class="type">int</span> sourceWidth <span class="operator">=</span> (columns <span class="operator">+</span> <span class="number">1</span>) <span class="operator">*</span> ItemSize; <span class="type">int</span> sourceHeight <span class="operator">=</span> (rows <span class="operator">+</span> <span class="number">1</span>) <span class="operator">*</span> ItemSize; painter<span class="operator">.</span>save(); <span class="type">double</span> xscale <span class="operator">=</span> printer<span class="operator">.</span>pageRect()<span class="operator">.</span>width() <span class="operator">/</span> <span class="type">double</span>(sourceWidth); <span class="type">double</span> yscale <span class="operator">=</span> printer<span class="operator">.</span>pageRect()<span class="operator">.</span>height() <span class="operator">/</span> <span class="type">double</span>(sourceHeight); <span class="type">double</span> scale <span class="operator">=</span> <a href="../qtcore/qtglobal.html#qMin">qMin</a>(xscale<span class="operator">,</span> yscale); painter<span class="operator">.</span>translate(printer<span class="operator">.</span>paperRect()<span class="operator">.</span>x() <span class="operator">+</span> printer<span class="operator">.</span>pageRect()<span class="operator">.</span>width() <span class="operator">/</span> <span class="number">2</span><span class="operator">,</span> printer<span class="operator">.</span>paperRect()<span class="operator">.</span>y() <span class="operator">+</span> printer<span class="operator">.</span>pageRect()<span class="operator">.</span>height() <span class="operator">/</span> <span class="number">2</span>); painter<span class="operator">.</span>scale(scale<span class="operator">,</span> scale); painter<span class="operator">.</span>translate(<span class="operator">-</span>sourceWidth <span class="operator">/</span> <span class="number">2</span><span class="operator">,</span> <span class="operator">-</span>sourceHeight <span class="operator">/</span> <span class="number">2</span>); <span class="type"><a href="qstyleoptionviewitem.html">QStyleOptionViewItem</a></span> option; <span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span> parent <span class="operator">=</span> <span class="type"><a href="../qtcore/qmodelindex.html">QModelIndex</a></span>(); <span class="type"><a href="qprogressdialog.html">QProgressDialog</a></span> progress(tr(<span class="string">"Printing..."</span>)<span class="operator">,</span> tr(<span class="string">"Cancel"</span>)<span class="operator">,</span> <span class="number">0</span><span class="operator">,</span> rows<span class="operator">,</span> <span class="keyword">this</span>); progress<span class="operator">.</span>setWindowModality(<span class="type"><a href="../qtcore/qt.html">Qt</a></span><span class="operator">::</span>ApplicationModal); <span class="type">float</span> y <span class="operator">=</span> ItemSize <span class="operator">/</span> <span class="number">2</span>; <span class="keyword">for</span> (<span class="type">int</span> row <span class="operator">=</span> <span class="number">0</span>; row <span class="operator"><</span> rows; <span class="operator">+</span><span class="operator">+</span>row) { progress<span class="operator">.</span>setValue(row); <a href="qapplication.html#qApp">qApp</a><span class="operator">-</span><span class="operator">></span>processEvents(); <span class="keyword">if</span> (progress<span class="operator">.</span>wasCanceled()) <span class="keyword">break</span>; <span class="type">float</span> x <span class="operator">=</span> ItemSize <span class="operator">/</span> <span class="number">2</span>; <span class="keyword">for</span> (<span class="type">int</span> column <span class="operator">=</span> <span class="number">0</span>; column <span class="operator"><</span> columns; <span class="operator">+</span><span class="operator">+</span>column) { option<span class="operator">.</span>rect <span class="operator">=</span> <span class="type"><a href="../qtcore/qrect.html">QRect</a></span>(<span class="type">int</span>(x)<span class="operator">,</span> <span class="type">int</span>(y)<span class="operator">,</span> ItemSize<span class="operator">,</span> ItemSize); view<span class="operator">-</span><span class="operator">></span>itemDelegate()<span class="operator">-</span><span class="operator">></span>paint(<span class="operator">&</span>painter<span class="operator">,</span> option<span class="operator">,</span> model<span class="operator">-</span><span class="operator">></span>index(row<span class="operator">,</span> column<span class="operator">,</span> parent)); x <span class="operator">=</span> x <span class="operator">+</span> ItemSize; } y <span class="operator">=</span> y <span class="operator">+</span> ItemSize; } progress<span class="operator">.</span>setValue(rows); painter<span class="operator">.</span>restore(); painter<span class="operator">.</span>end(); <span class="keyword">if</span> (progress<span class="operator">.</span>wasCanceled()) { <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>information(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">"Printing canceled"</span>)<span class="operator">,</span> tr(<span class="string">"The printing process was canceled."</span>)<span class="operator">,</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>Cancel); } <span class="preprocessor">#else</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>information(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">"Printing canceled"</span>)<span class="operator">,</span> tr(<span class="string">"Printing is not supported on this Qt build"</span>)<span class="operator">,</span> <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>Cancel); <span class="preprocessor">#endif</span> } <span class="type">void</span> MainWindow<span class="operator">::</span>showAboutBox() { <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>about(<span class="keyword">this</span><span class="operator">,</span> tr(<span class="string">"About the Pixelator example"</span>)<span class="operator">,</span> tr(<span class="string">"This example demonstrates how a standard view and a custom\n"</span> <span class="string">"delegate can be used to produce a specialized representation\n"</span> <span class="string">"of data in a simple custom model."</span>)); } <span class="type">void</span> MainWindow<span class="operator">::</span>updateView() { view<span class="operator">-</span><span class="operator">></span>resizeColumnsToContents(); view<span class="operator">-</span><span class="operator">></span>resizeRowsToContents(); } </pre> </div> <!-- @@@itemviews/pixelator/mainwindow.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>