<?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>notepad.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-tutorials-notepad-example.html">Getting Started Programming with Qt Widgets</a></td><td >notepad.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">notepad.cpp Example File</h1> <span class="subtitle">tutorials/notepad/notepad.cpp</span> <!-- $$$tutorials/notepad/notepad.cpp-description --> <div class="descr"> <a name="details"></a> <pre class="cpp"> <span class="comment">/**************************************************************************** ** ** Copyright (C) 2017 The Qt Company Ltd. ** Contact: https://www.qt.io/licensing/ ** ** This file is part of the documentation 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 <QFile></span> <span class="preprocessor">#include <QFileDialog></span> <span class="preprocessor">#include <QTextStream></span> <span class="preprocessor">#include <QMessageBox></span> <span class="preprocessor">#if defined(QT_PRINTSUPPORT_LIB)</span> <span class="preprocessor">#include <QtPrintSupport/qtprintsupportglobal.h></span> <span class="preprocessor">#if QT_CONFIG(printer)</span> <span class="preprocessor">#if QT_CONFIG(printdialog)</span> <span class="preprocessor">#include <QPrintDialog></span> <span class="preprocessor">#endif // QT_CONFIG(printdialog)</span> <span class="preprocessor">#include <QPrinter></span> <span class="preprocessor">#endif // QT_CONFIG(printer)</span> <span class="preprocessor">#endif // QT_PRINTSUPPORT_LIB</span> <span class="preprocessor">#include <QFont></span> <span class="preprocessor">#include <QFontDialog></span> <span class="preprocessor">#include "notepad.h"</span> <span class="preprocessor">#include "ui_notepad.h"</span> Notepad<span class="operator">::</span>Notepad(<span class="type"><a href="qwidget.html">QWidget</a></span> <span class="operator">*</span>parent) : <span class="type"><a href="qmainwindow.html">QMainWindow</a></span>(parent)<span class="operator">,</span> ui(<span class="keyword">new</span> Ui<span class="operator">::</span>Notepad) { ui<span class="operator">-</span><span class="operator">></span>setupUi(<span class="keyword">this</span>); <span class="keyword">this</span><span class="operator">-</span><span class="operator">></span>setCentralWidget(ui<span class="operator">-</span><span class="operator">></span>textEdit); connect(ui<span class="operator">-</span><span class="operator">></span>actionNew<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>Notepad<span class="operator">::</span>newDocument); connect(ui<span class="operator">-</span><span class="operator">></span>actionOpen<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>Notepad<span class="operator">::</span>open); connect(ui<span class="operator">-</span><span class="operator">></span>actionSave<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>Notepad<span class="operator">::</span>save); connect(ui<span class="operator">-</span><span class="operator">></span>actionSave_as<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>Notepad<span class="operator">::</span>saveAs); connect(ui<span class="operator">-</span><span class="operator">></span>actionPrint<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>Notepad<span class="operator">::</span>print); connect(ui<span class="operator">-</span><span class="operator">></span>actionExit<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>Notepad<span class="operator">::</span>exit); connect(ui<span class="operator">-</span><span class="operator">></span>actionCopy<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>Notepad<span class="operator">::</span>copy); connect(ui<span class="operator">-</span><span class="operator">></span>actionCut<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>Notepad<span class="operator">::</span>cut); connect(ui<span class="operator">-</span><span class="operator">></span>actionPaste<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>Notepad<span class="operator">::</span>paste); connect(ui<span class="operator">-</span><span class="operator">></span>actionUndo<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>Notepad<span class="operator">::</span>undo); connect(ui<span class="operator">-</span><span class="operator">></span>actionRedo<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>Notepad<span class="operator">::</span>redo); connect(ui<span class="operator">-</span><span class="operator">></span>actionFont<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>Notepad<span class="operator">::</span>selectFont); connect(ui<span class="operator">-</span><span class="operator">></span>actionBold<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>Notepad<span class="operator">::</span>setFontBold); connect(ui<span class="operator">-</span><span class="operator">></span>actionUnderline<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>Notepad<span class="operator">::</span>setFontUnderline); connect(ui<span class="operator">-</span><span class="operator">></span>actionItalic<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>Notepad<span class="operator">::</span>setFontItalic); connect(ui<span class="operator">-</span><span class="operator">></span>actionAbout<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>Notepad<span class="operator">::</span>about); <span class="comment">// Disable menu actions for unavailable features</span> <span class="preprocessor">#if !QT_CONFIG(printer)</span> ui<span class="operator">-</span><span class="operator">></span>actionPrint<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); <span class="preprocessor">#endif</span> <span class="preprocessor">#if !QT_CONFIG(clipboard)</span> ui<span class="operator">-</span><span class="operator">></span>actionCut<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); ui<span class="operator">-</span><span class="operator">></span>actionCopy<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); ui<span class="operator">-</span><span class="operator">></span>actionPaste<span class="operator">-</span><span class="operator">></span>setEnabled(<span class="keyword">false</span>); <span class="preprocessor">#endif</span> } Notepad<span class="operator">::</span><span class="operator">~</span>Notepad() { <span class="keyword">delete</span> ui; } <span class="type">void</span> Notepad<span class="operator">::</span>newDocument() { currentFile<span class="operator">.</span>clear(); ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>setText(<span class="type"><a href="../qtcore/qstring.html">QString</a></span>()); } <span class="type">void</span> Notepad<span class="operator">::</span>open() { <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> <span class="string">"Open the file"</span>); <span class="type"><a href="../qtcore/qfile.html">QFile</a></span> file(fileName); currentFile <span class="operator">=</span> fileName; <span class="keyword">if</span> (<span class="operator">!</span>file<span class="operator">.</span>open(<span class="type"><a href="../qtcore/qiodevice.html">QIODevice</a></span><span class="operator">::</span>ReadOnly <span class="operator">|</span> <span class="type"><a href="../qtcore/qfile.html">QFile</a></span><span class="operator">::</span>Text)) { <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>warning(<span class="keyword">this</span><span class="operator">,</span> <span class="string">"Warning"</span><span class="operator">,</span> <span class="string">"Cannot open file: "</span> <span class="operator">+</span> file<span class="operator">.</span>errorString()); <span class="keyword">return</span>; } setWindowTitle(fileName); <span class="type"><a href="../qtcore/qtextstream.html">QTextStream</a></span> in(<span class="operator">&</span>file); <span class="type"><a href="../qtcore/qstring.html">QString</a></span> text <span class="operator">=</span> in<span class="operator">.</span>readAll(); ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>setText(text); file<span class="operator">.</span>close(); } <span class="type">void</span> Notepad<span class="operator">::</span>save() { <span class="type"><a href="../qtcore/qstring.html">QString</a></span> fileName; <span class="comment">// If we don't have a filename from before, get one.</span> <span class="keyword">if</span> (currentFile<span class="operator">.</span>isEmpty()) { fileName <span class="operator">=</span> <span class="type"><a href="qfiledialog.html">QFileDialog</a></span><span class="operator">::</span>getSaveFileName(<span class="keyword">this</span><span class="operator">,</span> <span class="string">"Save"</span>); currentFile <span class="operator">=</span> fileName; } <span class="keyword">else</span> { fileName <span class="operator">=</span> currentFile; } <span class="type"><a href="../qtcore/qfile.html">QFile</a></span> file(fileName); <span class="keyword">if</span> (<span class="operator">!</span>file<span class="operator">.</span>open(<span class="type"><a href="../qtcore/qiodevice.html">QIODevice</a></span><span class="operator">::</span>WriteOnly <span class="operator">|</span> <span class="type"><a href="../qtcore/qfile.html">QFile</a></span><span class="operator">::</span>Text)) { <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>warning(<span class="keyword">this</span><span class="operator">,</span> <span class="string">"Warning"</span><span class="operator">,</span> <span class="string">"Cannot save file: "</span> <span class="operator">+</span> file<span class="operator">.</span>errorString()); <span class="keyword">return</span>; } setWindowTitle(fileName); <span class="type"><a href="../qtcore/qtextstream.html">QTextStream</a></span> out(<span class="operator">&</span>file); <span class="type"><a href="../qtcore/qstring.html">QString</a></span> text <span class="operator">=</span> ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>toPlainText(); out <span class="operator"><</span><span class="operator"><</span> text; file<span class="operator">.</span>close(); } <span class="type">void</span> Notepad<span class="operator">::</span>saveAs() { <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>getSaveFileName(<span class="keyword">this</span><span class="operator">,</span> <span class="string">"Save as"</span>); <span class="type"><a href="../qtcore/qfile.html">QFile</a></span> file(fileName); <span class="keyword">if</span> (<span class="operator">!</span>file<span class="operator">.</span>open(<span class="type"><a href="../qtcore/qfile.html">QFile</a></span><span class="operator">::</span>WriteOnly <span class="operator">|</span> <span class="type"><a href="../qtcore/qfile.html">QFile</a></span><span class="operator">::</span>Text)) { <span class="type"><a href="qmessagebox.html">QMessageBox</a></span><span class="operator">::</span>warning(<span class="keyword">this</span><span class="operator">,</span> <span class="string">"Warning"</span><span class="operator">,</span> <span class="string">"Cannot save file: "</span> <span class="operator">+</span> file<span class="operator">.</span>errorString()); <span class="keyword">return</span>; } currentFile <span class="operator">=</span> fileName; setWindowTitle(fileName); <span class="type"><a href="../qtcore/qtextstream.html">QTextStream</a></span> out(<span class="operator">&</span>file); <span class="type"><a href="../qtcore/qstring.html">QString</a></span> text <span class="operator">=</span> ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>toPlainText(); out <span class="operator"><</span><span class="operator"><</span> text; file<span class="operator">.</span>close(); } <span class="type">void</span> Notepad<span class="operator">::</span>print() { <span class="preprocessor">#if QT_CONFIG(printer)</span> <span class="type">QPrinter</span> printDev; <span class="preprocessor">#if QT_CONFIG(printdialog)</span> <span class="type">QPrintDialog</span> dialog(<span class="operator">&</span>printDev<span class="operator">,</span> <span class="keyword">this</span>); <span class="keyword">if</span> (dialog<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>Rejected) <span class="keyword">return</span>; <span class="preprocessor">#endif // QT_CONFIG(printdialog)</span> ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>print(<span class="operator">&</span>printDev); <span class="preprocessor">#endif // QT_CONFIG(printer)</span> } <span class="type">void</span> Notepad<span class="operator">::</span>exit() { <span class="type"><a href="../qtcore/qcoreapplication.html">QCoreApplication</a></span><span class="operator">::</span>quit(); } <span class="type">void</span> Notepad<span class="operator">::</span>copy() { <span class="preprocessor">#if QT_CONFIG(clipboard)</span> ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>copy(); <span class="preprocessor">#endif</span> } <span class="type">void</span> Notepad<span class="operator">::</span>cut() { <span class="preprocessor">#if QT_CONFIG(clipboard)</span> ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>cut(); <span class="preprocessor">#endif</span> } <span class="type">void</span> Notepad<span class="operator">::</span>paste() { <span class="preprocessor">#if QT_CONFIG(clipboard)</span> ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>paste(); <span class="preprocessor">#endif</span> } <span class="type">void</span> Notepad<span class="operator">::</span>undo() { ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>undo(); } <span class="type">void</span> Notepad<span class="operator">::</span>redo() { ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>redo(); } <span class="type">void</span> Notepad<span class="operator">::</span>selectFont() { bool fontSelected; <span class="type"><a href="../qtgui/qfont.html">QFont</a></span> font <span class="operator">=</span> <span class="type"><a href="qfontdialog.html">QFontDialog</a></span><span class="operator">::</span>getFont(<span class="operator">&</span>fontSelected<span class="operator">,</span> <span class="keyword">this</span>); <span class="keyword">if</span> (fontSelected) ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>setFont(font); } <span class="type">void</span> Notepad<span class="operator">::</span>setFontUnderline(bool underline) { ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>setFontUnderline(underline); } <span class="type">void</span> Notepad<span class="operator">::</span>setFontItalic(bool italic) { ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>setFontItalic(italic); } <span class="type">void</span> Notepad<span class="operator">::</span>setFontBold(bool bold) { bold <span class="operator">?</span> ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>setFontWeight(<span class="type"><a href="../qtgui/qfont.html">QFont</a></span><span class="operator">::</span>Bold) : ui<span class="operator">-</span><span class="operator">></span>textEdit<span class="operator">-</span><span class="operator">></span>setFontWeight(<span class="type"><a href="../qtgui/qfont.html">QFont</a></span><span class="operator">::</span>Normal); } <span class="type">void</span> Notepad<span class="operator">::</span>about() { <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 MDI"</span>)<span class="operator">,</span> tr(<span class="string">"The <b>Notepad</b> example demonstrates how to code a basic "</span> <span class="string">"text editor using QtWidgets"</span>)); } </pre> </div> <!-- @@@tutorials/notepad/notepad.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>