<?xml version="1.0" encoding="iso-8859-1"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <title>Qt 4.2: mainwindow.cpp Example File (mainwindows/sdi/mainwindow.cpp)</title> <link href="classic.css" rel="stylesheet" type="text/css" /> </head> <body> <table border="0" cellpadding="0" cellspacing="0" width="100%"> <tr> <td align="left" valign="top" width="32"><a href="http://www.trolltech.com/products/qt"><img src="images/qt-logo.png" align="left" width="32" height="32" border="0" /></a></td> <td width="1"> </td><td class="postheader" valign="center"><a href="index.html"><font color="#004faf">Home</font></a> · <a href="classes.html"><font color="#004faf">All Classes</font></a> · <a href="mainclasses.html"><font color="#004faf">Main Classes</font></a> · <a href="groups.html"><font color="#004faf">Grouped Classes</font></a> · <a href="modules.html"><font color="#004faf">Modules</font></a> · <a href="functions.html"><font color="#004faf">Functions</font></a></td> <td align="right" valign="top" width="230"><a href="http://www.trolltech.com"><img src="images/trolltech-logo.png" align="right" width="203" height="32" border="0" /></a></td></tr></table><h1 align="center">mainwindow.cpp Example File<br /><sup><sup>mainwindows/sdi/mainwindow.cpp</sup></sup></h1> <pre> /**************************************************************************** ** ** Copyright (C) 2004-2006 Trolltech ASA. All rights reserved. ** ** This file is part of the example classes of the Qt Toolkit. ** ** This file may be used under the terms of the GNU General Public ** License version 2.0 as published by the Free Software Foundation ** and appearing in the file LICENSE.GPL included in the packaging of ** this file. Please review the following information to ensure GNU ** General Public Licensing requirements will be met: ** http:<span class="comment">//www.trolltech.com/products/qt/opensource.html</span> ** ** If you are unsure which license is appropriate for your use, please ** review the following information: ** http:<span class="comment">//www.trolltech.com/products/qt/licensing.html or contact the</span> ** sales department at sales@trolltech.com. ** ** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE ** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. ** ****************************************************************************/ #include <QtGui> #include "mainwindow.h" MainWindow::MainWindow() { init(); setCurrentFile(""); } MainWindow::MainWindow(const QString &fileName) { init(); loadFile(fileName); } void MainWindow::closeEvent(QCloseEvent *event) { if (maybeSave()) { writeSettings(); event->accept(); } else { event->ignore(); } } void MainWindow::newFile() { MainWindow *other = new MainWindow; other->move(x() + 40, y() + 40); other->show(); } void MainWindow::open() { QString fileName = QFileDialog::getOpenFileName(this); if (!fileName.isEmpty()) { MainWindow *existing = findMainWindow(fileName); if (existing) { existing->show(); existing->raise(); existing->activateWindow(); return; } if (isUntitled && textEdit->document()->isEmpty() && !isWindowModified()) { loadFile(fileName); } else { MainWindow *other = new MainWindow(fileName); if (other->isUntitled) { delete other; return; } other->move(x() + 40, y() + 40); other->show(); } } } bool MainWindow::save() { if (isUntitled) { return saveAs(); } else { return saveFile(curFile); } } bool MainWindow::saveAs() { QString fileName = QFileDialog::getSaveFileName(this, tr("Save As"), curFile); if (fileName.isEmpty()) return false; return saveFile(fileName); } void MainWindow::about() { QMessageBox::about(this, tr("About SDI"), tr("The <b>SDI</b> example demonstrates how to write single " "document interface applications using Qt.")); } void MainWindow::documentWasModified() { setWindowModified(true); } void MainWindow::init() { setAttribute(Qt::WA_DeleteOnClose); isUntitled = true; textEdit = new QTextEdit; setCentralWidget(textEdit); createActions(); createMenus(); createToolBars(); createStatusBar(); readSettings(); connect(textEdit->document(), SIGNAL(contentsChanged()), this, SLOT(documentWasModified())); } void MainWindow::createActions() { newAct = new QAction(QIcon(":/images/new.png"), tr("&New"), this); newAct->setShortcut(tr("Ctrl+N")); newAct->setStatusTip(tr("Create a new file")); connect(newAct, SIGNAL(triggered()), this, SLOT(newFile())); openAct = new QAction(QIcon(":/images/open.png"), tr("&Open..."), this); openAct->setShortcut(tr("Ctrl+O")); openAct->setStatusTip(tr("Open an existing file")); connect(openAct, SIGNAL(triggered()), this, SLOT(open())); saveAct = new QAction(QIcon(":/images/save.png"), tr("&Save"), this); saveAct->setShortcut(tr("Ctrl+S")); saveAct->setStatusTip(tr("Save the document to disk")); connect(saveAct, SIGNAL(triggered()), this, SLOT(save())); saveAsAct = new QAction(tr("Save &As..."), this); saveAsAct->setStatusTip(tr("Save the document under a new name")); connect(saveAsAct, SIGNAL(triggered()), this, SLOT(saveAs())); closeAct = new QAction(tr("&Close"), this); closeAct->setShortcut(tr("Ctrl+W")); closeAct->setStatusTip(tr("Close this window")); connect(closeAct, SIGNAL(triggered()), this, SLOT(close())); exitAct = new QAction(tr("E&xit"), this); exitAct->setShortcut(tr("Ctrl+Q")); exitAct->setStatusTip(tr("Exit the application")); connect(exitAct, SIGNAL(triggered()), qApp, SLOT(closeAllWindows())); cutAct = new QAction(QIcon(":/images/cut.png"), tr("Cu&t"), this); cutAct->setShortcut(tr("Ctrl+X")); cutAct->setStatusTip(tr("Cut the current selection's contents to the " "clipboard")); connect(cutAct, SIGNAL(triggered()), textEdit, SLOT(cut())); copyAct = new QAction(QIcon(":/images/copy.png"), tr("&Copy"), this); copyAct->setShortcut(tr("Ctrl+C")); copyAct->setStatusTip(tr("Copy the current selection's contents to the " "clipboard")); connect(copyAct, SIGNAL(triggered()), textEdit, SLOT(copy())); pasteAct = new QAction(QIcon(":/images/paste.png"), tr("&Paste"), this); pasteAct->setShortcut(tr("Ctrl+V")); pasteAct->setStatusTip(tr("Paste the clipboard's contents into the current " "selection")); connect(pasteAct, SIGNAL(triggered()), textEdit, SLOT(paste())); aboutAct = new QAction(tr("&About"), this); aboutAct->setStatusTip(tr("Show the application's About box")); connect(aboutAct, SIGNAL(triggered()), this, SLOT(about())); aboutQtAct = new QAction(tr("About &Qt"), this); aboutQtAct->setStatusTip(tr("Show the Qt library's About box")); connect(aboutQtAct, SIGNAL(triggered()), qApp, SLOT(aboutQt())); cutAct->setEnabled(false); copyAct->setEnabled(false); connect(textEdit, SIGNAL(copyAvailable(bool)), cutAct, SLOT(setEnabled(bool))); connect(textEdit, SIGNAL(copyAvailable(bool)), copyAct, SLOT(setEnabled(bool))); } void MainWindow::createMenus() { fileMenu = menuBar()->addMenu(tr("&File")); fileMenu->addAction(newAct); fileMenu->addAction(openAct); fileMenu->addAction(saveAct); fileMenu->addAction(saveAsAct); fileMenu->addSeparator(); fileMenu->addAction(closeAct); fileMenu->addAction(exitAct); editMenu = menuBar()->addMenu(tr("&Edit")); editMenu->addAction(cutAct); editMenu->addAction(copyAct); editMenu->addAction(pasteAct); menuBar()->addSeparator(); helpMenu = menuBar()->addMenu(tr("&Help")); helpMenu->addAction(aboutAct); helpMenu->addAction(aboutQtAct); } void MainWindow::createToolBars() { fileToolBar = addToolBar(tr("File")); fileToolBar->addAction(newAct); fileToolBar->addAction(openAct); fileToolBar->addAction(saveAct); editToolBar = addToolBar(tr("Edit")); editToolBar->addAction(cutAct); editToolBar->addAction(copyAct); editToolBar->addAction(pasteAct); } void MainWindow::createStatusBar() { statusBar()->showMessage(tr("Ready")); } void MainWindow::readSettings() { QSettings settings("Trolltech", "SDI Example"); QPoint pos = settings.value("pos", QPoint(200, 200)).toPoint(); QSize size = settings.value("size", QSize(400, 400)).toSize(); move(pos); resize(size); } void MainWindow::writeSettings() { QSettings settings("Trolltech", "SDI Example"); settings.setValue("pos", pos()); settings.setValue("size", size()); } bool MainWindow::maybeSave() { if (textEdit->document()->isModified()) { QMessageBox::StandardButton ret; ret = QMessageBox::warning(this, tr("SDI"), tr("The document has been modified.\n" "Do you want to save your changes?"), QMessageBox::Save | QMessageBox::Discard | QMessageBox::Cancel); if (ret == QMessageBox::Save) return save(); else if (ret == QMessageBox::Cancel) return false; } return true; } void MainWindow::loadFile(const QString &fileName) { QFile file(fileName); if (!file.open(QFile::ReadOnly | QFile::Text)) { QMessageBox::warning(this, tr("SDI"), tr("Cannot read file %1:\n%2.") .arg(fileName) .arg(file.errorString())); return; } QTextStream in(&file); QApplication::setOverrideCursor(Qt::WaitCursor); textEdit->setPlainText(in.readAll()); QApplication::restoreOverrideCursor(); setCurrentFile(fileName); statusBar()->showMessage(tr("File loaded"), 2000); } bool MainWindow::saveFile(const QString &fileName) { QFile file(fileName); if (!file.open(QFile::WriteOnly | QFile::Text)) { QMessageBox::warning(this, tr("SDI"), tr("Cannot write file %1:\n%2.") .arg(fileName) .arg(file.errorString())); return false; } QTextStream out(&file); QApplication::setOverrideCursor(Qt::WaitCursor); out << textEdit->toPlainText(); QApplication::restoreOverrideCursor(); setCurrentFile(fileName); statusBar()->showMessage(tr("File saved"), 2000); return true; } void MainWindow::setCurrentFile(const QString &fileName) { static int sequenceNumber = 1; isUntitled = fileName.isEmpty(); if (isUntitled) { curFile = tr("document%1.txt").arg(sequenceNumber++); } else { curFile = QFileInfo(fileName).canonicalFilePath(); } textEdit->document()->setModified(false); setWindowModified(false); setWindowTitle(tr("%1[*] - %2").arg(strippedName(curFile)) .arg(tr("SDI"))); } QString MainWindow::strippedName(const QString &fullFileName) { return QFileInfo(fullFileName).fileName(); } MainWindow *MainWindow::findMainWindow(const QString &fileName) { QString canonicalFilePath = QFileInfo(fileName).canonicalFilePath(); foreach (QWidget *widget, qApp->topLevelWidgets()) { MainWindow *mainWin = qobject_cast<MainWindow *>(widget); if (mainWin && mainWin->curFile == canonicalFilePath) return mainWin; } return 0; }</pre> <p /><address><hr /><div align="center"> <table width="100%" cellspacing="0" border="0"><tr class="address"> <td width="30%">Copyright © 2006 <a href="trolltech.html">Trolltech</a></td> <td width="40%" align="center"><a href="trademarks.html">Trademarks</a></td> <td width="30%" align="right"><div align="right">Qt 4.2.1</div></td> </tr></table></div></address></body> </html>