Mega Code Archive
Qt based application window
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#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
QT_BEGIN_NAMESPACE
class QAction;
class QMenu;
class QPlainTextEdit;
QT_END_NAMESPACE
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
MainWindow();
protected:
void closeEvent(QCloseEvent *event);
private slots:
void newFile();
void open();
bool save();
bool saveAs();
void about();
void documentWasModified();
private:
void createActions();
void createMenus();
void createToolBars();
void createStatusBar();
void readSettings();
void writeSettings();
bool maybeSave();
void loadFile(const QString &fileName);
bool saveFile(const QString &fileName);
void setCurrentFile(const QString &fileName);
QString strippedName(const QString &fullFileName);
QPlainTextEdit *textEdit;
QString curFile;
QMenu *fileMenu;
QMenu *editMenu;
QMenu *helpMenu;
QToolBar *fileToolBar;
QToolBar *editToolBar;
QAction *newAct;
QAction *openAct;
QAction *saveAct;
QAction *saveAsAct;
QAction *exitAct;
QAction *cutAct;
QAction *copyAct;
QAction *pasteAct;
QAction *aboutAct;
QAction *aboutQtAct;
};
#endif
#include <QtGui>
#include "mainwindow.h"
MainWindow::MainWindow()
{
textEdit = new QPlainTextEdit;
setCentralWidget(textEdit);
createActions();
createMenus();
createToolBars();
createStatusBar();
readSettings();
connect(textEdit->document(), SIGNAL(contentsChanged()),
this, SLOT(documentWasModified()));
setCurrentFile("");
setUnifiedTitleAndToolBarOnMac(true);
}
void MainWindow::closeEvent(QCloseEvent *event)
{
if (maybeSave()) {
writeSettings();
event->accept();
} else {
event->ignore();
}
}
void MainWindow::newFile()
{
if (maybeSave()) {
textEdit->clear();
setCurrentFile("");
}
}
void MainWindow::open()
{
if (maybeSave()) {
QString fileName = QFileDialog::getOpenFileName(this);
if (!fileName.isEmpty())
loadFile(fileName);
}
}
bool MainWindow::save()
{
if (curFile.isEmpty()) {
return saveAs();
} else {
return saveFile(curFile);
}
}
bool MainWindow::saveAs()
{
QString fileName = QFileDialog::getSaveFileName(this);
if (fileName.isEmpty())
return false;
return saveFile(fileName);
}
void MainWindow::about()
{
QMessageBox::about(this, tr("About Application"),
tr("The <b>Application</b> example demonstrates how to "
"write modern GUI applications using Qt, with a menu bar, "
"toolbars, and a status bar."));
}
void MainWindow::documentWasModified()
{
setWindowModified(textEdit->document()->isModified());
}
void MainWindow::createActions()
{
newAct = new QAction(QIcon(":/images/new.png"), tr("&New"), this);
newAct->setShortcuts(QKeySequence::New);
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->setShortcuts(QKeySequence::Open);
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->setShortcuts(QKeySequence::Save);
saveAct->setStatusTip(tr("Save the document to disk"));
connect(saveAct, SIGNAL(triggered()), this, SLOT(save()));
saveAsAct = new QAction(tr("Save &As..."), this);
saveAsAct->setShortcuts(QKeySequence::SaveAs);
saveAsAct->setStatusTip(tr("Save the document under a new name"));
connect(saveAsAct, SIGNAL(triggered()), this, SLOT(saveAs()));
exitAct = new QAction(tr("E&xit"), this);
exitAct->setShortcut(tr("Ctrl+Q"));
exitAct->setStatusTip(tr("Exit the application"));
connect(exitAct, SIGNAL(triggered()), this, SLOT(close()));
cutAct = new QAction(QIcon(":/images/cut.png"), tr("Cu&t"), this);
cutAct->setShortcuts(QKeySequence::Cut);
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->setShortcuts(QKeySequence::Copy);
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->setShortcuts(QKeySequence::Paste);
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(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", "Application Example");
QPoint pos = settings.value("pos", QPoint(200, 200)).toPoint();
QSize size = settings.value("size", QSize(400, 400)).toSize();
resize(size);
move(pos);
}
void MainWindow::writeSettings()
{
QSettings settings("Trolltech", "Application Example");
settings.setValue("pos", pos());
settings.setValue("size", size());
}
bool MainWindow::maybeSave()
{
if (textEdit->document()->isModified()) {
QMessageBox::StandardButton ret;
ret = QMessageBox::warning(this, tr("Application"),
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("Application"),
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("Application"),
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)
{
curFile = fileName;
textEdit->document()->setModified(false);
setWindowModified(false);
QString shownName;
if (curFile.isEmpty())
shownName = "untitled.txt";
else
shownName = strippedName(curFile);
setWindowTitle(tr("%1[*] - %2").arg(shownName).arg(tr("Application")));
}
QString MainWindow::strippedName(const QString &fullFileName)
{
return QFileInfo(fullFileName).fileName();
}
#include <QApplication>
#include "mainwindow.h"
int main(int argc, char *argv[])
{
Q_INIT_RESOURCE(application);
QApplication app(argc, argv);
MainWindow mainWin;
mainWin.show();
return app.exec();
}
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