mainwindow.cpp Example File
mainwindows/sdi/mainwindow.cpp
/****************************************************************************
**
** Copyright (C) 2004-2005 Trolltech AS. All rights reserved.
**
** This file is part of the documentation 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://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
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** 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()) {
int ret = QMessageBox::warning(this, tr("SDI"),
tr("The document has been modified.\n"
"Do you want to save your changes?"),
QMessageBox::Yes | QMessageBox::Default,
QMessageBox::No,
QMessageBox::Cancel | QMessageBox::Escape);
if (ret == QMessageBox::Yes)
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;
}
