Qt Reference Documentation

mdichild.cpp Example File

mainwindows/mdi/mdichild.cpp
 /****************************************************************************
 **
 ** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation ([email protected])
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** 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 Nokia Corporation and its Subsidiary(-ies) 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."
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <QtGui>

 #include "mdichild.h"

 MdiChild::MdiChild()
 {
     setAttribute(Qt::WA_DeleteOnClose);
     isUntitled = true;
 }

 void MdiChild::newFile()
 {
     static int sequenceNumber = 1;

     isUntitled = true;
     curFile = tr("document%1.txt").arg(sequenceNumber++);
     setWindowTitle(curFile + "[*]");

     connect(document(), SIGNAL(contentsChanged()),
             this, SLOT(documentWasModified()));
 }

 bool MdiChild::loadFile(const QString &fileName)
 {
     QFile file(fileName);
     if (!file.open(QFile::ReadOnly | QFile::Text)) {
         QMessageBox::warning(this, tr("MDI"),
                              tr("Cannot read file %1:\n%2.")
                              .arg(fileName)
                              .arg(file.errorString()));
         return false;
     }

     QTextStream in(&file);
     QApplication::setOverrideCursor(Qt::WaitCursor);
     setPlainText(in.readAll());
     QApplication::restoreOverrideCursor();

     setCurrentFile(fileName);

     connect(document(), SIGNAL(contentsChanged()),
             this, SLOT(documentWasModified()));

     return true;
 }

 bool MdiChild::save()
 {
     if (isUntitled) {
         return saveAs();
     } else {
         return saveFile(curFile);
     }
 }

 bool MdiChild::saveAs()
 {
     QString fileName = QFileDialog::getSaveFileName(this, tr("Save As"),
                                                     curFile);
     if (fileName.isEmpty())
         return false;

     return saveFile(fileName);
 }

 bool MdiChild::saveFile(const QString &fileName)
 {
     QFile file(fileName);
     if (!file.open(QFile::WriteOnly | QFile::Text)) {
         QMessageBox::warning(this, tr("MDI"),
                              tr("Cannot write file %1:\n%2.")
                              .arg(fileName)
                              .arg(file.errorString()));
         return false;
     }

     QTextStream out(&file);
     QApplication::setOverrideCursor(Qt::WaitCursor);
     out << toPlainText();
     QApplication::restoreOverrideCursor();

     setCurrentFile(fileName);
     return true;
 }

 QString MdiChild::userFriendlyCurrentFile()
 {
     return strippedName(curFile);
 }

 void MdiChild::closeEvent(QCloseEvent *event)
 {
     if (maybeSave()) {
         event->accept();
     } else {
         event->ignore();
     }
 }

 void MdiChild::documentWasModified()
 {
     setWindowModified(document()->isModified());
 }

 bool MdiChild::maybeSave()
 {
     if (document()->isModified()) {
         QMessageBox::StandardButton ret;
         ret = QMessageBox::warning(this, tr("MDI"),
                      tr("'%1' has been modified.\n"
                         "Do you want to save your changes?")
                      .arg(userFriendlyCurrentFile()),
                      QMessageBox::Save | QMessageBox::Discard
                      | QMessageBox::Cancel);
         if (ret == QMessageBox::Save)
             return save();
         else if (ret == QMessageBox::Cancel)
             return false;
     }
     return true;
 }

 void MdiChild::setCurrentFile(const QString &fileName)
 {
     curFile = QFileInfo(fileName).canonicalFilePath();
     isUntitled = false;
     document()->setModified(false);
     setWindowModified(false);
     setWindowTitle(userFriendlyCurrentFile() + "[*]");
 }

 QString MdiChild::strippedName(const QString &fullFileName)
 {
     return QFileInfo(fullFileName).fileName();
 }
X

Thank you for giving your feedback.

Make sure it is related to this specific page. For more general bugs and requests, please use the Qt Bug Tracker.