mainwindow.cpp Example File
mainwindows/sdi/mainwindow.cpp
#include <QtGui>
#include "mainwindow.h"
MainWindow::MainWindow()
{
setAttribute(Qt::WA_DeleteOnClose);
textEdit = new QTextEdit(this);
setCentralWidget(textEdit);
createActions();
createMenus();
createToolBars();
createStatusBar();
readSettings();
connect(textEdit->document(), SIGNAL(contentsChanged()),
this, SLOT(documentWasModified()));
setWindowTitle(tr("SDI"));
}
void MainWindow::closeEvent(QCloseEvent *event)
{
if (maybeSave()) {
writeSettings();
event->accept();
} else {
event->ignore();
}
}
void MainWindow::newFile()
{
const int OFFSET = 20;
MainWindow *other = new MainWindow;
other->move(x() + OFFSET, y() + OFFSET);
other->show();
}
void MainWindow::open()
{
if (maybeSave()) {
QString fileName = QFileDialog::getOpenFileName(this);
if (!fileName.isEmpty())
loadFile(fileName);
}
}
bool MainWindow::save()
{
if (curFile.isEmpty()) {
return saveAs();
} else {
saveFile(curFile);
return true;
}
}
bool MainWindow::saveAs()
{
QString fileName = QFileDialog::getSaveFileName(this);
if (fileName.isEmpty())
return false;
if (QFile::exists(fileName)) {
int ret = QMessageBox::warning(this, tr("SDI"),
tr("File %1 already exists.\n"
"Do you want to overwrite it?")
.arg(QDir::convertSeparators(fileName)),
QMessageBox::Yes | QMessageBox::Default,
QMessageBox::No | QMessageBox::Escape);
if (ret == QMessageBox::No)
return true;
}
saveFile(fileName);
return true;
}
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()
{
modLabel->setText(tr("MOD"));
}
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()));
}
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()
{
modLabel = new QLabel(tr(" MOD "));
modLabel->setAlignment(Qt::AlignHCenter);
modLabel->setMinimumSize(modLabel->sizeHint());
modLabel->clear();
statusBar()->addWidget(modLabel, 0, true);
}
void MainWindow::readSettings()
{
QSettings settings("doc.trolltech.com", "SDI");
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("doc.trolltech.com", "SDI");
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);
}
void 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;
}
QTextStream out(&file);
QApplication::setOverrideCursor(Qt::WaitCursor);
out << textEdit->toPlainText();
QApplication::restoreOverrideCursor();
setCurrentFile(fileName);
statusBar()->showMessage(tr("File saved"), 2000);
}
void MainWindow::setCurrentFile(const QString &fileName)
{
curFile = fileName;
modLabel->clear();
textEdit->document()->setModified(false);
if (curFile.isEmpty())
setWindowTitle(tr("SDI"));
else
setWindowTitle(tr("%1 - %2").arg(strippedName(curFile))
.arg(tr("SDI")));
}
QString MainWindow::strippedName(const QString &fullFileName)
{
return QFileInfo(fullFileName).fileName();
}