Add recent file handling to SDI/MDI and remove the recentfiles example.

The existing recentfiles example was basically a clone of the SDI
example with a "Recent" menu added. Assuming it is better to have
it all in one place, the functionality is merged into the existing
SDI/MDI examples.

- Implement recently opened files handling using a submenu and a
  QSettings array in the SDI/MDI examples.
- Remove recentfiles example.

Change-Id: Id5a1ab9fa1c2e6b9ec81309cfe74cf86f450392a
Reviewed-by: Topi Reiniö <topi.reinio@digia.com>

13 files changed, 240 insertions, 464 deletions

diff --git a/doc/src/images/recentfiles-example.png b/doc/src/images/recentfiles-example.png
deleted file mode 100644
index 8a1f2e5509..0000000000
--- a/doc/src/images/recentfiles-example.png
+++ /dev/null
diff --git a/examples/widgets/doc/src/application.qdoc b/examples/widgets/doc/src/application.qdoc
index 048b4bfd21..cd284ecba0 100644
--- a/examples/widgets/doc/src/application.qdoc
+++ b/examples/widgets/doc/src/application.qdoc
@@ -50,11 +50,10 @@
 
     To keep the example simple, recently opened files aren't shown in
     the \uicontrol{File} menu, even though this feature is desired in 90%
-    of applications. The \l{mainwindows/recentfiles}{Recent Files}
-    example shows how to implement this. Furthermore, this example
-    can only load one file at a time. The \l{mainwindows/sdi}{SDI}
-    and \l{mainwindows/mdi}{MDI} examples shows how to lift these
-    restrictions.
+    of applications. Furthermore, this example can only load one file at a
+    time. The \l{mainwindows/sdi}{SDI} and \l{mainwindows/mdi}{MDI} examples
+    show how to lift these restrictions and how to implement recently opened files
+    handling.
 
     \section1 MainWindow Class Definition
 
diff --git a/examples/widgets/doc/src/recentfiles.qdoc b/examples/widgets/doc/src/recentfiles.qdoc
deleted file mode 100644
index b58c9a1f76..0000000000
--- a/examples/widgets/doc/src/recentfiles.qdoc
+++ /dev/null
@@ -1,37 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
-**
-** This file is part of the documentation of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:FDL$
-** 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 http://www.qt.io/terms-conditions. For further
-** information use the contact form at http://www.qt.io/contact-us.
-**
-** GNU Free Documentation License Usage
-** Alternatively, this file may be used under the terms of the GNU Free
-** Documentation License version 1.3 as published by the Free Software
-** Foundation and appearing in the file included in the packaging of
-** this file. Please review the following information to ensure
-** the GNU Free Documentation License version 1.3 requirements
-** will be met: http://www.gnu.org/copyleft/fdl.html.
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-/*!
-    \example mainwindows/recentfiles
-    \title Recent Files Example
-    \ingroup examples-mainwindow
-
-    \brief The Recent Files example shows how a standard File menu can be extended to show
-    the most recent files loaded by a main window application.
-
-    \image recentfiles-example.png
-*/
diff --git a/examples/widgets/mainwindows/mainwindows.pro b/examples/widgets/mainwindows/mainwindows.pro
index 52179ec9bd..dcda89abaf 100644
--- a/examples/widgets/mainwindows/mainwindows.pro
+++ b/examples/widgets/mainwindows/mainwindows.pro
@@ -4,5 +4,4 @@ SUBDIRS       = application \
                 mainwindow \
                 mdi \
                 menus \
-                recentfiles \
                 sdi
diff --git a/examples/widgets/mainwindows/mdi/main.cpp b/examples/widgets/mainwindows/mdi/main.cpp
index 5976c85c1c..f02285d1cf 100644
--- a/examples/widgets/mainwindows/mdi/main.cpp
+++ b/examples/widgets/mainwindows/mdi/main.cpp
@@ -49,6 +49,8 @@ int main(int argc, char *argv[])
     Q_INIT_RESOURCE(mdi);
 
     QApplication app(argc, argv);
+    QCoreApplication::setApplicationName("MDI Example");
+    QCoreApplication::setOrganizationName("QtProject");
     QCoreApplication::setApplicationVersion(QT_VERSION_STR);
     QCommandLineParser parser;
     parser.setApplicationDescription("Qt MDI Example");
diff --git a/examples/widgets/mainwindows/mdi/mainwindow.cpp b/examples/widgets/mainwindows/mdi/mainwindow.cpp
index 4dada5ce70..35136c81c4 100644
--- a/examples/widgets/mainwindows/mdi/mainwindow.cpp
+++ b/examples/widgets/mainwindows/mdi/mainwindow.cpp
@@ -82,19 +82,24 @@ void MainWindow::newFile()
 
 void MainWindow::open()
 {
-    QString fileName = QFileDialog::getOpenFileName(this);
-    if (!fileName.isEmpty()) {
-        if (QMdiSubWindow *existing = findMdiChild(fileName)) {
-            mdiArea->setActiveSubWindow(existing);
-            return;
-        }
+    const QString fileName = QFileDialog::getOpenFileName(this);
+    if (!fileName.isEmpty())
+        openFile(fileName);
+}
 
-        if (openFile(fileName))
-            statusBar()->showMessage(tr("File loaded"), 2000);
+bool MainWindow::openFile(const QString &fileName)
+{
+    if (QMdiSubWindow *existing = findMdiChild(fileName)) {
+        mdiArea->setActiveSubWindow(existing);
+        return true;
     }
+    const bool succeeded = loadFile(fileName);
+    if (succeeded)
+        statusBar()->showMessage(tr("File loaded"), 2000);
+    return succeeded;
 }
 
-bool MainWindow::openFile(const QString &fileName)
+bool MainWindow::loadFile(const QString &fileName)
 {
     MdiChild *child = createMdiChild();
     const bool succeeded = child->loadFile(fileName);
@@ -102,9 +107,87 @@ bool MainWindow::openFile(const QString &fileName)
         child->show();
     else
         child->close();
+    MainWindow::prependToRecentFiles(fileName);
     return succeeded;
 }
 
+static inline QString recentFilesKey() { return QStringLiteral("recentFileList"); }
+static inline QString fileKey() { return QStringLiteral("file"); }
+
+static QStringList readRecentFiles(QSettings &settings)
+{
+    QStringList result;
+    const int count = settings.beginReadArray(recentFilesKey());
+    for (int i = 0; i < count; ++i) {
+        settings.setArrayIndex(i);
+        result.append(settings.value(fileKey()).toString());
+    }
+    settings.endArray();
+    return result;
+}
+
+static void writeRecentFiles(const QStringList &files, QSettings &settings)
+{
+    const int count = files.size();
+    settings.beginWriteArray(recentFilesKey());
+    for (int i = 0; i < count; ++i) {
+        settings.setArrayIndex(i);
+        settings.setValue(fileKey(), files.at(i));
+    }
+    settings.endArray();
+}
+
+bool MainWindow::hasRecentFiles()
+{
+    QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
+    const int count = settings.beginReadArray(recentFilesKey());
+    settings.endArray();
+    return count > 0;
+}
+
+void MainWindow::prependToRecentFiles(const QString &fileName)
+{
+    QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
+
+    const QStringList oldRecentFiles = readRecentFiles(settings);
+    QStringList recentFiles = oldRecentFiles;
+    recentFiles.removeAll(fileName);
+    recentFiles.prepend(fileName);
+    if (oldRecentFiles != recentFiles)
+        writeRecentFiles(recentFiles, settings);
+
+    setRecentFilesVisible(!recentFiles.isEmpty());
+}
+
+void MainWindow::setRecentFilesVisible(bool visible)
+{
+    recentFileSubMenuAct->setVisible(visible);
+    recentFileSeparator->setVisible(visible);
+}
+
+void MainWindow::updateRecentFileActions()
+{
+    QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
+
+    const QStringList recentFiles = readRecentFiles(settings);
+    const int count = qMin(int(MaxRecentFiles), recentFiles.size());
+    int i = 0;
+    for ( ; i < count; ++i) {
+        const QString fileName = QFileInfo(recentFiles.at(i)).fileName();
+        recentFileActs[i]->setText(tr("&%1 %2").arg(i + 1).arg(fileName));
+        recentFileActs[i]->setData(recentFiles.at(i));
+        recentFileActs[i]->setVisible(true);
+    }
+    for ( ; i < MaxRecentFiles; ++i)
+        recentFileActs[i]->setVisible(false);
+}
+
+void MainWindow::openRecentFile()
+{
+    if (const QAction *action = qobject_cast<const QAction *>(sender()))
+        openFile(action->data().toString());
+}
+
 void MainWindow::save()
 {
     if (activeMdiChild() && activeMdiChild()->save())
@@ -113,8 +196,11 @@ void MainWindow::save()
 
 void MainWindow::saveAs()
 {
-    if (activeMdiChild() && activeMdiChild()->saveAs())
+    MdiChild *child = activeMdiChild();
+    if (child && child->saveAs()) {
         statusBar()->showMessage(tr("File saved"), 2000);
+        MainWindow::prependToRecentFiles(child->currentFile());
+    }
 }
 
 #ifndef QT_NO_CLIPBOARD
@@ -262,8 +348,23 @@ void MainWindow::createActions()
 
     fileMenu->addSeparator();
 
+    QMenu *recentMenu = fileMenu->addMenu(tr("Recent..."));
+    connect(recentMenu, &QMenu::aboutToShow, this, &MainWindow::updateRecentFileActions);
+    recentFileSubMenuAct = recentMenu->menuAction();
+
+    for (int i = 0; i < MaxRecentFiles; ++i) {
+        recentFileActs[i] = recentMenu->addAction(QString(), this, &MainWindow::openRecentFile);
+        recentFileActs[i]->setVisible(false);
+    }
+
+    recentFileSeparator = fileMenu->addSeparator();
+
+    setRecentFilesVisible(MainWindow::hasRecentFiles());
+
     fileMenu->addAction(tr("Switch layout direction"), this, &MainWindow::switchLayoutDirection);
 
+    fileMenu->addSeparator();
+
 //! [0]
     const QIcon exitIcon = QIcon::fromTheme("application-exit");
     QAction *exitAct = fileMenu->addAction(exitIcon, tr("E&xit"), qApp, &QApplication::closeAllWindows);
diff --git a/examples/widgets/mainwindows/mdi/mainwindow.h b/examples/widgets/mainwindows/mdi/mainwindow.h
index bdc2a6a09d..3ac60282fd 100644
--- a/examples/widgets/mainwindows/mdi/mainwindow.h
+++ b/examples/widgets/mainwindows/mdi/mainwindow.h
@@ -68,6 +68,8 @@ private slots:
     void open();
     void save();
     void saveAs();
+    void updateRecentFileActions();
+    void openRecentFile();
 #ifndef QT_NO_CLIPBOARD
     void cut();
     void copy();
@@ -80,10 +82,16 @@ private slots:
     void switchLayoutDirection();
 
 private:
+    enum { MaxRecentFiles = 5 };
+
     void createActions();
     void createStatusBar();
     void readSettings();
     void writeSettings();
+    bool loadFile(const QString &fileName);
+    static bool hasRecentFiles();
+    void prependToRecentFiles(const QString &fileName);
+    void setRecentFilesVisible(bool visible);
     MdiChild *activeMdiChild() const;
     QMdiSubWindow *findMdiChild(const QString &fileName) const;
 
@@ -93,6 +101,9 @@ private:
     QAction *newAct;
     QAction *saveAct;
     QAction *saveAsAct;
+    QAction *recentFileActs[MaxRecentFiles];
+    QAction *recentFileSeparator;
+    QAction *recentFileSubMenuAct;
 #ifndef QT_NO_CLIPBOARD
     QAction *cutAct;
     QAction *copyAct;
diff --git a/examples/widgets/mainwindows/recentfiles/main.cpp b/examples/widgets/mainwindows/recentfiles/main.cpp
deleted file mode 100644
index 23ff3eda16..0000000000
--- a/examples/widgets/mainwindows/recentfiles/main.cpp
+++ /dev/null
@@ -1,53 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
-**
-** This file is part of the examples of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:BSD$
-** 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
-**     contributors may be used to endorse or promote products derived
-**     from this software without specific prior written permission.
-**
-**
-** 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
-** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include <QApplication>
-
-#include "mainwindow.h"
-
-int main(int argc, char *argv[])
-{
-    QApplication app(argc, argv);
-    app.setOrganizationName("QtProject");
-    app.setApplicationName("Recent Files Example");
-    MainWindow *mainWin = new MainWindow;
-    mainWin->show();
-    return app.exec();
-}
diff --git a/examples/widgets/mainwindows/recentfiles/mainwindow.cpp b/examples/widgets/mainwindows/recentfiles/mainwindow.cpp
deleted file mode 100644
index b89797092a..0000000000
--- a/examples/widgets/mainwindows/recentfiles/mainwindow.cpp
+++ /dev/null
@@ -1,251 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
-**
-** This file is part of the examples of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:BSD$
-** 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
-**     contributors may be used to endorse or promote products derived
-**     from this software without specific prior written permission.
-**
-**
-** 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
-** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#include <QtWidgets>
-
-#include "mainwindow.h"
-
-MainWindow::MainWindow()
-{
-    setAttribute(Qt::WA_DeleteOnClose);
-
-    textEdit = new QTextEdit;
-    setCentralWidget(textEdit);
-
-    createActions();
-    createMenus();
-    (void)statusBar();
-
-    setWindowFilePath(QString());
-    resize(400, 300);
-}
-
-void MainWindow::newFile()
-{
-    MainWindow *other = new MainWindow;
-    other->show();
-}
-
-void MainWindow::open()
-{
-    QString fileName = QFileDialog::getOpenFileName(this);
-    if (!fileName.isEmpty())
-        loadFile(fileName);
-}
-
-void MainWindow::save()
-{
-    if (curFile.isEmpty())
-        saveAs();
-    else
-        saveFile(curFile);
-}
-
-void MainWindow::saveAs()
-{
-    QString fileName = QFileDialog::getSaveFileName(this);
-    if (fileName.isEmpty())
-        return;
-
-    saveFile(fileName);
-}
-
-void MainWindow::openRecentFile()
-{
-    QAction *action = qobject_cast<QAction *>(sender());
-    if (action)
-        loadFile(action->data().toString());
-}
-
-void MainWindow::about()
-{
-   QMessageBox::about(this, tr("About Recent Files"),
-            tr("The <b>Recent Files</b> example demonstrates how to provide a "
-               "recently used file menu in a Qt application."));
-}
-
-void MainWindow::createActions()
-{
-    newAct = new QAction(tr("&New"), this);
-    newAct->setShortcuts(QKeySequence::New);
-    newAct->setStatusTip(tr("Create a new file"));
-    connect(newAct, SIGNAL(triggered()), this, SLOT(newFile()));
-
-    openAct = new QAction(tr("&Open..."), this);
-    openAct->setShortcuts(QKeySequence::Open);
-    openAct->setStatusTip(tr("Open an existing file"));
-    connect(openAct, SIGNAL(triggered()), this, SLOT(open()));
-
-    saveAct = new QAction(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()));
-
-    for (int i = 0; i < MaxRecentFiles; ++i) {
-        recentFileActs[i] = new QAction(this);
-        recentFileActs[i]->setVisible(false);
-        connect(recentFileActs[i], SIGNAL(triggered()),
-                this, SLOT(openRecentFile()));
-    }
-
-    exitAct = new QAction(tr("E&xit"), this);
-    exitAct->setShortcuts(QKeySequence::Quit);
-    exitAct->setStatusTip(tr("Exit the application"));
-    connect(exitAct, SIGNAL(triggered()), qApp, SLOT(closeAllWindows()));
-
-    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);
-    separatorAct = fileMenu->addSeparator();
-    for (int i = 0; i < MaxRecentFiles; ++i)
-        fileMenu->addAction(recentFileActs[i]);
-    fileMenu->addSeparator();
-    fileMenu->addAction(exitAct);
-    updateRecentFileActions();
-
-    menuBar()->addSeparator();
-
-    helpMenu = menuBar()->addMenu(tr("&Help"));
-    helpMenu->addAction(aboutAct);
-    helpMenu->addAction(aboutQtAct);
-}
-
-void MainWindow::loadFile(const QString &fileName)
-{
-    QFile file(fileName);
-    if (!file.open(QFile::ReadOnly | QFile::Text)) {
-        QMessageBox::warning(this, tr("Recent Files"),
-                             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("Recent Files"),
-                             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;
-    setWindowFilePath(curFile);
-
-    QSettings settings;
-    QStringList files = settings.value("recentFileList").toStringList();
-    files.removeAll(fileName);
-    files.prepend(fileName);
-    while (files.size() > MaxRecentFiles)
-        files.removeLast();
-
-    settings.setValue("recentFileList", files);
-
-    foreach (QWidget *widget, QApplication::topLevelWidgets()) {
-        MainWindow *mainWin = qobject_cast<MainWindow *>(widget);
-        if (mainWin)
-            mainWin->updateRecentFileActions();
-    }
-}
-
-void MainWindow::updateRecentFileActions()
-{
-    QSettings settings;
-    QStringList files = settings.value("recentFileList").toStringList();
-
-    int numRecentFiles = qMin(files.size(), (int)MaxRecentFiles);
-
-    for (int i = 0; i < numRecentFiles; ++i) {
-        QString text = tr("&%1 %2").arg(i + 1).arg(strippedName(files[i]));
-        recentFileActs[i]->setText(text);
-        recentFileActs[i]->setData(files[i]);
-        recentFileActs[i]->setVisible(true);
-    }
-    for (int j = numRecentFiles; j < MaxRecentFiles; ++j)
-        recentFileActs[j]->setVisible(false);
-
-    separatorAct->setVisible(numRecentFiles > 0);
-}
-
-QString MainWindow::strippedName(const QString &fullFileName)
-{
-    return QFileInfo(fullFileName).fileName();
-}
diff --git a/examples/widgets/mainwindows/recentfiles/mainwindow.h b/examples/widgets/mainwindows/recentfiles/mainwindow.h
deleted file mode 100644
index 95252ca525..0000000000
--- a/examples/widgets/mainwindows/recentfiles/mainwindow.h
+++ /dev/null
@@ -1,96 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2015 The Qt Company Ltd.
-** Contact: http://www.qt.io/licensing/
-**
-** This file is part of the examples of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:BSD$
-** 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
-**     contributors may be used to endorse or promote products derived
-**     from this software without specific prior written permission.
-**
-**
-** 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
-** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef MAINWINDOW_H
-#define MAINWINDOW_H
-
-#include <QList>
-#include <QMainWindow>
-
-QT_BEGIN_NAMESPACE
-class QAction;
-class QMenu;
-class QTextEdit;
-QT_END_NAMESPACE
-
-class MainWindow : public QMainWindow
-{
-    Q_OBJECT
-
-public:
-    MainWindow();
-
-private slots:
-    void newFile();
-    void open();
-    void save();
-    void saveAs();
-    void openRecentFile();
-    void about();
-
-private:
-    void createActions();
-    void createMenus();
-    void loadFile(const QString &fileName);
-    void saveFile(const QString &fileName);
-    void setCurrentFile(const QString &fileName);
-    void updateRecentFileActions();
-    QString strippedName(const QString &fullFileName);
-
-    QString curFile;
-
-    QTextEdit *textEdit;
-    QMenu *fileMenu;
-    QMenu *recentFilesMenu;
-    QMenu *helpMenu;
-    QAction *newAct;
-    QAction *openAct;
-    QAction *saveAct;
-    QAction *saveAsAct;
-    QAction *exitAct;
-    QAction *aboutAct;
-    QAction *aboutQtAct;
-    QAction *separatorAct;
-
-    enum { MaxRecentFiles = 5 };
-    QAction *recentFileActs[MaxRecentFiles];
-};
-
-#endif
diff --git a/examples/widgets/mainwindows/recentfiles/recentfiles.pro b/examples/widgets/mainwindows/recentfiles/recentfiles.pro
deleted file mode 100644
index ccf948f560..0000000000
--- a/examples/widgets/mainwindows/recentfiles/recentfiles.pro
+++ /dev/null
@@ -1,9 +0,0 @@
-QT += widgets
-
-HEADERS       = mainwindow.h
-SOURCES       = main.cpp \
-                mainwindow.cpp
-
-# install
-target.path = $$[QT_INSTALL_EXAMPLES]/widgets/mainwindows/recentfiles
-INSTALLS += target
diff --git a/examples/widgets/mainwindows/sdi/mainwindow.cpp b/examples/widgets/mainwindows/sdi/mainwindow.cpp
index 0fba7f792b..29618f9ac2 100644
--- a/examples/widgets/mainwindows/sdi/mainwindow.cpp
+++ b/examples/widgets/mainwindows/sdi/mainwindow.cpp
@@ -74,9 +74,12 @@ void MainWindow::newFile()
 void MainWindow::open()
 {
     const QString fileName = QFileDialog::getOpenFileName(this);
-    if (fileName.isEmpty())
-        return;
+    if (!fileName.isEmpty())
+        openFile(fileName);
+}
 
+void MainWindow::openFile(const QString &fileName)
+{
     MainWindow *existing = findMainWindow(fileName);
     if (existing) {
         existing->show();
@@ -196,6 +199,19 @@ void MainWindow::createActions()
 
     fileMenu->addSeparator();
 
+    QMenu *recentMenu = fileMenu->addMenu(tr("Recent..."));
+    connect(recentMenu, &QMenu::aboutToShow, this, &MainWindow::updateRecentFileActions);
+    recentFileSubMenuAct = recentMenu->menuAction();
+
+    for (int i = 0; i < MaxRecentFiles; ++i) {
+        recentFileActs[i] = recentMenu->addAction(QString(), this, &MainWindow::openRecentFile);
+        recentFileActs[i]->setVisible(false);
+    }
+
+    recentFileSeparator = fileMenu->addSeparator();
+
+    setRecentFilesVisible(MainWindow::hasRecentFiles());
+
     QAction *closeAct = fileMenu->addAction(tr("&Close"), this, &QWidget::close);
     closeAct->setShortcut(tr("Ctrl+W"));
     closeAct->setStatusTip(tr("Close this window"));
@@ -316,6 +332,83 @@ void MainWindow::loadFile(const QString &fileName)
     statusBar()->showMessage(tr("File loaded"), 2000);
 }
 
+void MainWindow::setRecentFilesVisible(bool visible)
+{
+    recentFileSubMenuAct->setVisible(visible);
+    recentFileSeparator->setVisible(visible);
+}
+
+static inline QString recentFilesKey() { return QStringLiteral("recentFileList"); }
+static inline QString fileKey() { return QStringLiteral("file"); }
+
+static QStringList readRecentFiles(QSettings &settings)
+{
+    QStringList result;
+    const int count = settings.beginReadArray(recentFilesKey());
+    for (int i = 0; i < count; ++i) {
+        settings.setArrayIndex(i);
+        result.append(settings.value(fileKey()).toString());
+    }
+    settings.endArray();
+    return result;
+}
+
+static void writeRecentFiles(const QStringList &files, QSettings &settings)
+{
+    const int count = files.size();
+    settings.beginWriteArray(recentFilesKey());
+    for (int i = 0; i < count; ++i) {
+        settings.setArrayIndex(i);
+        settings.setValue(fileKey(), files.at(i));
+    }
+    settings.endArray();
+}
+
+bool MainWindow::hasRecentFiles()
+{
+    QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
+    const int count = settings.beginReadArray(recentFilesKey());
+    settings.endArray();
+    return count > 0;
+}
+
+void MainWindow::prependToRecentFiles(const QString &fileName)
+{
+    QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
+
+    const QStringList oldRecentFiles = readRecentFiles(settings);
+    QStringList recentFiles = oldRecentFiles;
+    recentFiles.removeAll(fileName);
+    recentFiles.prepend(fileName);
+    if (oldRecentFiles != recentFiles)
+        writeRecentFiles(recentFiles, settings);
+
+    setRecentFilesVisible(!recentFiles.isEmpty());
+}
+
+void MainWindow::updateRecentFileActions()
+{
+    QSettings settings(QCoreApplication::organizationName(), QCoreApplication::applicationName());
+
+    const QStringList recentFiles = readRecentFiles(settings);
+    const int count = qMin(int(MaxRecentFiles), recentFiles.size());
+    int i = 0;
+    for ( ; i < count; ++i) {
+        const QString fileName = MainWindow::strippedName(recentFiles.at(i));
+        recentFileActs[i]->setText(tr("&%1 %2").arg(i + 1).arg(fileName));
+        recentFileActs[i]->setData(recentFiles.at(i));
+        recentFileActs[i]->setVisible(true);
+    }
+    for ( ; i < MaxRecentFiles; ++i)
+        recentFileActs[i]->setVisible(false);
+}
+
+void MainWindow::openRecentFile()
+{
+    if (const QAction *action = qobject_cast<const QAction *>(sender()))
+        openFile(action->data().toString());
+}
+
 bool MainWindow::saveFile(const QString &fileName)
 {
     QFile file(fileName);
@@ -349,6 +442,10 @@ void MainWindow::setCurrentFile(const QString &fileName)
 
     textEdit->document()->setModified(false);
     setWindowModified(false);
+
+    if (!isUntitled && windowFilePath() != curFile)
+        MainWindow::prependToRecentFiles(curFile);
+
     setWindowFilePath(curFile);
 }
 
diff --git a/examples/widgets/mainwindows/sdi/mainwindow.h b/examples/widgets/mainwindows/sdi/mainwindow.h
index 3c01f38566..66ac618c72 100644
--- a/examples/widgets/mainwindows/sdi/mainwindow.h
+++ b/examples/widgets/mainwindows/sdi/mainwindow.h
@@ -70,23 +70,36 @@ private slots:
     void open();
     bool save();
     bool saveAs();
+    void updateRecentFileActions();
+    void openRecentFile();
     void about();
     void documentWasModified();
 
 private:
+    enum { MaxRecentFiles = 5 };
+
     void init();
     void createActions();
     void createStatusBar();
     void readSettings();
     void writeSettings();
     bool maybeSave();
+    void openFile(const QString &fileName);
     void loadFile(const QString &fileName);
+    static bool hasRecentFiles();
+    void prependToRecentFiles(const QString &fileName);
+    void setRecentFilesVisible(bool visible);
     bool saveFile(const QString &fileName);
     void setCurrentFile(const QString &fileName);
     static QString strippedName(const QString &fullFileName);
     MainWindow *findMainWindow(const QString &fileName) const;
 
     QTextEdit *textEdit;
+
+    QAction *recentFileActs[MaxRecentFiles];
+    QAction *recentFileSeparator;
+    QAction *recentFileSubMenuAct;
+
     QString curFile;
     bool isUntitled;
 };