mdichild.cpp Example File
mainwindows/mdi/mdichild.cpp
#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();
}