qt5base-lts/examples/widgets/mainwindows/application/mainwindow.cpp
Andreas Hartmetz 7f878c6217 Remove "fallback session management"
With the Qt6 compatibility break, it can finally be removed.
Closing windows (which might quit the application with
quitOnLastWindowClosed() true, the default) acted contrary to the
documentation of the commitDataRequest() signal, which could have
been a hint.

This removes the workaround API from the fix for QTBUG-49667 and
also removes the problematic feature that it worked around.

Change-Id: I672be58864ef062df7fb7f2a81658b92c4feedd2
Reviewed-by: Fabian Kosmale <fabian.kosmale@qt.io>
2020-09-01 10:16:15 +02:00

418 lines
13 KiB
C++

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in
** the documentation and/or other materials provided with the
** distribution.
** * Neither the name of The Qt Company Ltd nor the names of its
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** from this software without specific prior written permission.
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**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
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**
** $QT_END_LICENSE$
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****************************************************************************/
//! [0]
#include <QtWidgets>
#include "mainwindow.h"
//! [0]
//! [1]
MainWindow::MainWindow()
: textEdit(new QPlainTextEdit)
//! [1] //! [2]
{
setCentralWidget(textEdit);
createActions();
createStatusBar();
readSettings();
connect(textEdit->document(), &QTextDocument::contentsChanged,
this, &MainWindow::documentWasModified);
#ifndef QT_NO_SESSIONMANAGER
connect(qApp, &QGuiApplication::commitDataRequest,
this, &MainWindow::commitData);
#endif
setCurrentFile(QString());
setUnifiedTitleAndToolBarOnMac(true);
}
//! [2]
//! [3]
void MainWindow::closeEvent(QCloseEvent *event)
//! [3] //! [4]
{
if (maybeSave()) {
writeSettings();
event->accept();
} else {
event->ignore();
}
}
//! [4]
//! [5]
void MainWindow::newFile()
//! [5] //! [6]
{
if (maybeSave()) {
textEdit->clear();
setCurrentFile(QString());
}
}
//! [6]
//! [7]
void MainWindow::open()
//! [7] //! [8]
{
if (maybeSave()) {
QString fileName = QFileDialog::getOpenFileName(this);
if (!fileName.isEmpty())
loadFile(fileName);
}
}
//! [8]
//! [9]
bool MainWindow::save()
//! [9] //! [10]
{
if (curFile.isEmpty()) {
return saveAs();
} else {
return saveFile(curFile);
}
}
//! [10]
//! [11]
bool MainWindow::saveAs()
//! [11] //! [12]
{
QFileDialog dialog(this);
dialog.setWindowModality(Qt::WindowModal);
dialog.setAcceptMode(QFileDialog::AcceptSave);
if (dialog.exec() != QDialog::Accepted)
return false;
return saveFile(dialog.selectedFiles().first());
}
//! [12]
//! [13]
void MainWindow::about()
//! [13] //! [14]
{
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."));
}
//! [14]
//! [15]
void MainWindow::documentWasModified()
//! [15] //! [16]
{
setWindowModified(textEdit->document()->isModified());
}
//! [16]
//! [17]
void MainWindow::createActions()
//! [17] //! [18]
{
QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
QToolBar *fileToolBar = addToolBar(tr("File"));
const QIcon newIcon = QIcon::fromTheme("document-new", QIcon(":/images/new.png"));
QAction *newAct = new QAction(newIcon, tr("&New"), this);
newAct->setShortcuts(QKeySequence::New);
newAct->setStatusTip(tr("Create a new file"));
connect(newAct, &QAction::triggered, this, &MainWindow::newFile);
fileMenu->addAction(newAct);
fileToolBar->addAction(newAct);
//! [19]
const QIcon openIcon = QIcon::fromTheme("document-open", QIcon(":/images/open.png"));
QAction *openAct = new QAction(openIcon, tr("&Open..."), this);
openAct->setShortcuts(QKeySequence::Open);
openAct->setStatusTip(tr("Open an existing file"));
connect(openAct, &QAction::triggered, this, &MainWindow::open);
fileMenu->addAction(openAct);
fileToolBar->addAction(openAct);
//! [18] //! [19]
const QIcon saveIcon = QIcon::fromTheme("document-save", QIcon(":/images/save.png"));
QAction *saveAct = new QAction(saveIcon, tr("&Save"), this);
saveAct->setShortcuts(QKeySequence::Save);
saveAct->setStatusTip(tr("Save the document to disk"));
connect(saveAct, &QAction::triggered, this, &MainWindow::save);
fileMenu->addAction(saveAct);
fileToolBar->addAction(saveAct);
const QIcon saveAsIcon = QIcon::fromTheme("document-save-as");
QAction *saveAsAct = fileMenu->addAction(saveAsIcon, tr("Save &As..."), this, &MainWindow::saveAs);
saveAsAct->setShortcuts(QKeySequence::SaveAs);
saveAsAct->setStatusTip(tr("Save the document under a new name"));
//! [20]
fileMenu->addSeparator();
const QIcon exitIcon = QIcon::fromTheme("application-exit");
QAction *exitAct = fileMenu->addAction(exitIcon, tr("E&xit"), this, &QWidget::close);
exitAct->setShortcuts(QKeySequence::Quit);
//! [20]
exitAct->setStatusTip(tr("Exit the application"));
//! [21]
QMenu *editMenu = menuBar()->addMenu(tr("&Edit"));
QToolBar *editToolBar = addToolBar(tr("Edit"));
//!
#ifndef QT_NO_CLIPBOARD
const QIcon cutIcon = QIcon::fromTheme("edit-cut", QIcon(":/images/cut.png"));
QAction *cutAct = new QAction(cutIcon, tr("Cu&t"), this);
//! [21]
cutAct->setShortcuts(QKeySequence::Cut);
cutAct->setStatusTip(tr("Cut the current selection's contents to the "
"clipboard"));
connect(cutAct, &QAction::triggered, textEdit, &QPlainTextEdit::cut);
editMenu->addAction(cutAct);
editToolBar->addAction(cutAct);
const QIcon copyIcon = QIcon::fromTheme("edit-copy", QIcon(":/images/copy.png"));
QAction *copyAct = new QAction(copyIcon, tr("&Copy"), this);
copyAct->setShortcuts(QKeySequence::Copy);
copyAct->setStatusTip(tr("Copy the current selection's contents to the "
"clipboard"));
connect(copyAct, &QAction::triggered, textEdit, &QPlainTextEdit::copy);
editMenu->addAction(copyAct);
editToolBar->addAction(copyAct);
const QIcon pasteIcon = QIcon::fromTheme("edit-paste", QIcon(":/images/paste.png"));
QAction *pasteAct = new QAction(pasteIcon, tr("&Paste"), this);
pasteAct->setShortcuts(QKeySequence::Paste);
pasteAct->setStatusTip(tr("Paste the clipboard's contents into the current "
"selection"));
connect(pasteAct, &QAction::triggered, textEdit, &QPlainTextEdit::paste);
editMenu->addAction(pasteAct);
editToolBar->addAction(pasteAct);
menuBar()->addSeparator();
#endif // !QT_NO_CLIPBOARD
QMenu *helpMenu = menuBar()->addMenu(tr("&Help"));
QAction *aboutAct = helpMenu->addAction(tr("&About"), this, &MainWindow::about);
aboutAct->setStatusTip(tr("Show the application's About box"));
//! [22]
QAction *aboutQtAct = helpMenu->addAction(tr("About &Qt"), qApp, &QApplication::aboutQt);
aboutQtAct->setStatusTip(tr("Show the Qt library's About box"));
//! [22]
//! [23]
#ifndef QT_NO_CLIPBOARD
cutAct->setEnabled(false);
//! [23] //! [24]
copyAct->setEnabled(false);
connect(textEdit, &QPlainTextEdit::copyAvailable, cutAct, &QAction::setEnabled);
connect(textEdit, &QPlainTextEdit::copyAvailable, copyAct, &QAction::setEnabled);
#endif // !QT_NO_CLIPBOARD
}
//! [24]
//! [32]
void MainWindow::createStatusBar()
//! [32] //! [33]
{
statusBar()->showMessage(tr("Ready"));
}
//! [33]
//! [34] //! [35]
void MainWindow::readSettings()
//! [34] //! [36]
{
QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
const QByteArray geometry = settings.value("geometry", QByteArray()).toByteArray();
if (geometry.isEmpty()) {
const QRect availableGeometry = screen()->availableGeometry();
resize(availableGeometry.width() / 3, availableGeometry.height() / 2);
move((availableGeometry.width() - width()) / 2,
(availableGeometry.height() - height()) / 2);
} else {
restoreGeometry(geometry);
}
}
//! [35] //! [36]
//! [37] //! [38]
void MainWindow::writeSettings()
//! [37] //! [39]
{
QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
settings.setValue("geometry", saveGeometry());
}
//! [38] //! [39]
//! [40]
bool MainWindow::maybeSave()
//! [40] //! [41]
{
if (!textEdit->document()->isModified())
return true;
const QMessageBox::StandardButton 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);
switch (ret) {
case QMessageBox::Save:
return save();
case QMessageBox::Cancel:
return false;
default:
break;
}
return true;
}
//! [41]
//! [42]
void MainWindow::loadFile(const QString &fileName)
//! [42] //! [43]
{
QFile file(fileName);
if (!file.open(QFile::ReadOnly | QFile::Text)) {
QMessageBox::warning(this, tr("Application"),
tr("Cannot read file %1:\n%2.")
.arg(QDir::toNativeSeparators(fileName), file.errorString()));
return;
}
QTextStream in(&file);
#ifndef QT_NO_CURSOR
QGuiApplication::setOverrideCursor(Qt::WaitCursor);
#endif
textEdit->setPlainText(in.readAll());
#ifndef QT_NO_CURSOR
QGuiApplication::restoreOverrideCursor();
#endif
setCurrentFile(fileName);
statusBar()->showMessage(tr("File loaded"), 2000);
}
//! [43]
//! [44]
bool MainWindow::saveFile(const QString &fileName)
//! [44] //! [45]
{
QString errorMessage;
QGuiApplication::setOverrideCursor(Qt::WaitCursor);
QSaveFile file(fileName);
if (file.open(QFile::WriteOnly | QFile::Text)) {
QTextStream out(&file);
out << textEdit->toPlainText();
if (!file.commit()) {
errorMessage = tr("Cannot write file %1:\n%2.")
.arg(QDir::toNativeSeparators(fileName), file.errorString());
}
} else {
errorMessage = tr("Cannot open file %1 for writing:\n%2.")
.arg(QDir::toNativeSeparators(fileName), file.errorString());
}
QGuiApplication::restoreOverrideCursor();
if (!errorMessage.isEmpty()) {
QMessageBox::warning(this, tr("Application"), errorMessage);
return false;
}
setCurrentFile(fileName);
statusBar()->showMessage(tr("File saved"), 2000);
return true;
}
//! [45]
//! [46]
void MainWindow::setCurrentFile(const QString &fileName)
//! [46] //! [47]
{
curFile = fileName;
textEdit->document()->setModified(false);
setWindowModified(false);
QString shownName = curFile;
if (curFile.isEmpty())
shownName = "untitled.txt";
setWindowFilePath(shownName);
}
//! [47]
//! [48]
QString MainWindow::strippedName(const QString &fullFileName)
//! [48] //! [49]
{
return QFileInfo(fullFileName).fileName();
}
//! [49]
#ifndef QT_NO_SESSIONMANAGER
void MainWindow::commitData(QSessionManager &manager)
{
if (manager.allowsInteraction()) {
if (!maybeSave())
manager.cancel();
} else {
// Non-interactive: save without asking
if (textEdit->document()->isModified())
save();
}
}
#endif