mdichild.cpp Example File

mainwindows/mdi/mdichild.cpp
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#include <QtWidgets> #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(), &QTextDocument::contentsChanged, this, &MdiChild::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(), &QTextDocument::contentsChanged, this, &MdiChild::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(QDir::toNativeSeparators(fileName), 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()) return true; const QMessageBox::StandardButton 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); switch (ret) { case QMessageBox::Save: return save(); case QMessageBox::Cancel: return false; default: break; } 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(); }