Merge remote-tracking branch 'origin/5.6' into dev

Conflicts:
	tests/auto/corelib/io/qfile/tst_qfile.cpp
	tests/auto/corelib/io/qprocess/tst_qprocess.cpp
	tests/auto/corelib/tools/qversionnumber/qversionnumber.pro

Change-Id: Ia93ce500349d96a2fbf0b4a37b73f088cc505c6e

50 files changed, 345 insertions, 333 deletions

diff --git a/examples/embedded/digiflip/digiflip.cpp b/examples/embedded/digiflip/digiflip.cpp
index 3bb3023caf..af4289efb3 100644
--- a/examples/embedded/digiflip/digiflip.cpp
+++ b/examples/embedded/digiflip/digiflip.cpp
@@ -112,7 +112,7 @@ protected:
 
         QString str = QString::number(n);
         if (str.length() == 1)
-            str.prepend("0");
+            str.prepend('0');
 
         QFont font;
         font.setFamily("Helvetica");
diff --git a/examples/gui/openglwindow/main.cpp b/examples/gui/openglwindow/main.cpp
index 6ab05176a6..d79ecd6510 100644
--- a/examples/gui/openglwindow/main.cpp
+++ b/examples/gui/openglwindow/main.cpp
@@ -57,8 +57,6 @@ public:
     void render() Q_DECL_OVERRIDE;
 
 private:
-    GLuint loadShader(GLenum type, const char *source);
-
     GLuint m_posAttr;
     GLuint m_colAttr;
     GLuint m_matrixUniform;
@@ -113,14 +111,6 @@ static const char *fragmentShaderSource =
 //! [3]
 
 //! [4]
-GLuint TriangleWindow::loadShader(GLenum type, const char *source)
-{
-    GLuint shader = glCreateShader(type);
-    glShaderSource(shader, 1, &source, 0);
-    glCompileShader(shader);
-    return shader;
-}
-
 void TriangleWindow::initialize()
 {
     m_program = new QOpenGLShaderProgram(this);
diff --git a/examples/network/doc/src/torrent.qdoc b/examples/network/doc/src/torrent.qdoc
index 08857f02d3..9576e08cfa 100644
--- a/examples/network/doc/src/torrent.qdoc
+++ b/examples/network/doc/src/torrent.qdoc
@@ -35,37 +35,4 @@
     supported by the Qt Network APIs.
 
     \image torrent-example.png
-
-    \section1 License Information
-
-    The implementation of the US Secure Hash Algorithm 1 (SHA1) in this example is
-    derived from the original description in \l{http://www.rfc-editor.org/rfc/rfc3174.txt}{RFC 3174}.
-
-    \legalese
-    Copyright (C) The Internet Society (2001).  All Rights Reserved.
-
-    This document and translations of it may be copied and furnished to
-    others, and derivative works that comment on or otherwise explain it
-    or assist in its implementation may be prepared, copied, published
-    and distributed, in whole or in part, without restriction of any
-    kind, provided that the above copyright notice and this paragraph are
-    included on all such copies and derivative works.  However, this
-    document itself may not be modified in any way, such as by removing
-    the copyright notice or references to the Internet Society or other
-    Internet organizations, except as needed for the purpose of
-    developing Internet standards in which case the procedures for
-    copyrights defined in the Internet Standards process must be
-    followed, or as required to translate it into languages other than
-    English.
-
-    The limited permissions granted above are perpetual and will not be
-    revoked by the Internet Society or its successors or assigns.
-
-    This document and the information contained herein is provided on an
-    "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
-    TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
-    BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
-    HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
-    MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
-    \endlegalese
 */
diff --git a/examples/network/torrent/filemanager.cpp b/examples/network/torrent/filemanager.cpp
index b4e921b0a5..58330014cf 100644
--- a/examples/network/torrent/filemanager.cpp
+++ b/examples/network/torrent/filemanager.cpp
@@ -219,8 +219,8 @@ bool FileManager::generateFiles()
         QString prefix;
         if (!destinationPath.isEmpty()) {
             prefix = destinationPath;
-            if (!prefix.endsWith("/"))
-                prefix += "/";
+            if (!prefix.endsWith('/'))
+                prefix += '/';
             QDir dir;
             if (!dir.mkpath(prefix)) {
                 errString = tr("Failed to create directory %1").arg(prefix);
@@ -261,13 +261,13 @@ bool FileManager::generateFiles()
 
         if (!destinationPath.isEmpty()) {
             prefix = destinationPath;
-            if (!prefix.endsWith("/"))
-                prefix += "/";
+            if (!prefix.endsWith('/'))
+                prefix += '/';
         }
         if (!metaInfo.name().isEmpty()) {
             prefix += metaInfo.name();
-            if (!prefix.endsWith("/"))
-                prefix += "/";
+            if (!prefix.endsWith('/'))
+                prefix += '/';
         }
         if (!dir.mkpath(prefix)) {
             errString = tr("Failed to create directory %1").arg(prefix);
diff --git a/examples/network/torrent/metainfo.cpp b/examples/network/torrent/metainfo.cpp
index cca52c7e7e..52e7afe43a 100644
--- a/examples/network/torrent/metainfo.cpp
+++ b/examples/network/torrent/metainfo.cpp
@@ -96,7 +96,7 @@ bool MetaInfo::parse(const QByteArray &data)
             QByteArray path;
             foreach (QVariant p, pathElements) {
                 if (!path.isEmpty())
-                    path += "/";
+                    path += '/';
                 path += p.toByteArray();
             }
 
diff --git a/examples/opengl/contextinfo/widget.cpp b/examples/opengl/contextinfo/widget.cpp
index c318accf87..2d36fe4265 100644
--- a/examples/opengl/contextinfo/widget.cpp
+++ b/examples/opengl/contextinfo/widget.cpp
@@ -299,7 +299,7 @@ void Widget::printFormat(const QSurfaceFormat &format)
     QString opts;
     for (size_t i = 0; i < sizeof(options) / sizeof(Option); ++i)
         if (format.testOption(options[i].option))
-            opts += QString::fromLatin1(options[i].str) + QStringLiteral(" ");
+            opts += QString::fromLatin1(options[i].str) + QLatin1Char(' ');
     m_output->append(tr("Options: %1").arg(opts));
 
     for (size_t i = 0; i < sizeof(renderables) / sizeof(Renderable); ++i)
diff --git a/examples/qtconcurrent/wordcount/main.cpp b/examples/qtconcurrent/wordcount/main.cpp
index f45f2820c7..7f6d0f43ba 100644
--- a/examples/qtconcurrent/wordcount/main.cpp
+++ b/examples/qtconcurrent/wordcount/main.cpp
@@ -61,10 +61,10 @@ QStringList findFiles(const QString &startDir, QStringList filters)
     QDir dir(startDir);
 
     foreach (QString file, dir.entryList(filters, QDir::Files))
-        names += startDir + "/" + file;
+        names += startDir + '/' + file;
 
     foreach (QString subdir, dir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot))
-        names += findFiles(startDir + "/" + subdir, filters);
+        names += findFiles(startDir + '/' + subdir, filters);
     return names;
 }
 
@@ -81,7 +81,7 @@ WordCount singleThreadedWordCount(QStringList files)
         f.open(QIODevice::ReadOnly);
         QTextStream textStream(&f);
         while (textStream.atEnd() == false)
-            foreach(QString word, textStream.readLine().split(" "))
+            foreach (const QString &word, textStream.readLine().split(' '))
                 wordCount[word] += 1;
 
     }
@@ -100,7 +100,7 @@ WordCount countWords(const QString &file)
     WordCount wordCount;
 
     while (textStream.atEnd() == false)
-        foreach (QString word, textStream.readLine().split(" "))
+        foreach (const QString &word, textStream.readLine().split(' '))
             wordCount[word] += 1;
 
     return wordCount;
diff --git a/examples/sql/masterdetail/dialog.cpp b/examples/sql/masterdetail/dialog.cpp
index 5518707f58..3171acc448 100644
--- a/examples/sql/masterdetail/dialog.cpp
+++ b/examples/sql/masterdetail/dialog.cpp
@@ -153,7 +153,7 @@ void Dialog::addTracks(int albumId, QStringList tracks)
     for (int i = 0; i < tracks.count(); i++) {
         QString trackNumber = QString::number(i);
         if (i < 10)
-            trackNumber.prepend("0");
+            trackNumber.prepend('0');
 
         QDomText textNode = albumDetails.createTextNode(tracks.at(i));
 
diff --git a/examples/sql/querymodel/customsqlmodel.cpp b/examples/sql/querymodel/customsqlmodel.cpp
index 5966802abe..4cdfdd6ae3 100644
--- a/examples/sql/querymodel/customsqlmodel.cpp
+++ b/examples/sql/querymodel/customsqlmodel.cpp
@@ -53,7 +53,7 @@ QVariant CustomSqlModel::data(const QModelIndex &index, int role) const
     QVariant value = QSqlQueryModel::data(index, role);
     if (value.isValid() && role == Qt::DisplayRole) {
         if (index.column() == 0)
-            return value.toString().prepend("#");
+            return value.toString().prepend('#');
         else if (index.column() == 2)
             return value.toString().toUpper();
     }
diff --git a/examples/widgets/desktop/systray/doc/images/systemtray-editor.png b/examples/widgets/desktop/systray/doc/images/systemtray-editor.png
new file mode 100644
index 0000000000..fb15dea8cb
--- /dev/null
+++ b/examples/widgets/desktop/systray/doc/images/systemtray-editor.png
diff --git a/examples/widgets/desktop/systray/doc/images/systemtray-example.png b/examples/widgets/desktop/systray/doc/images/systemtray-example.png
new file mode 100644
index 0000000000..98b5c8133e
--- /dev/null
+++ b/examples/widgets/desktop/systray/doc/images/systemtray-example.png
diff --git a/examples/widgets/desktop/systray/doc/src/systray.qdoc b/examples/widgets/desktop/systray/doc/src/systray.qdoc
new file mode 100644
index 0000000000..074012b6a7
--- /dev/null
+++ b/examples/widgets/desktop/systray/doc/src/systray.qdoc
@@ -0,0 +1,183 @@
+/****************************************************************************
+**
+** 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 desktop/systray
+    \title System Tray Icon Example
+
+
+    The System Tray Icon example shows how to add an icon with a menu
+    and popup messages to a desktop environment's system tray.
+
+    \image systemtray-example.png Screenshot of the System Tray Icon.
+
+    Modern operating systems usually provide a special area on the
+    desktop, called the system tray or notification area, where
+    long-running applications can display icons and short messages.
+
+    This example consists of one single class, \c Window, providing
+    the main application window (i.e., an editor for the system tray
+    icon) and the associated icon.
+
+    \image systemtray-editor.png
+
+    The editor allows the user to choose the preferred icon as well as
+    set the balloon message's type and duration. The user can also
+    edit the message's title and body. Finally, the editor provide a
+    checkbox controlling whether the icon is actually shown in the
+    system tray, or not.
+
+    \section1 Window Class Definition
+
+    The \c Window class inherits QWidget:
+
+    \snippet desktop/systray/window.h 0
+
+    We implement several private slots to respond to user
+    interaction. The other private functions are only convenience
+    functions provided to simplify the constructor.
+
+    The tray icon is an instance of the QSystemTrayIcon class. To
+    check whether a system tray is present on the user's desktop, call
+    the static QSystemTrayIcon::isSystemTrayAvailable()
+    function. Associated with the icon, we provide a menu containing
+    the typical \gui minimize, \gui maximize, \gui restore and \gui
+    quit actions. We reimplement the QWidget::setVisible() function to
+    update the tray icon's menu whenever the editor's appearance
+    changes, e.g., when maximizing or minimizing the main application
+    window.
+
+    Finally, we reimplement QWidget's \l {QWidget::}{closeEvent()}
+    function to be able to inform the user (when closing the editor
+    window) that the program will keep running in the system tray
+    until the user chooses the \gui Quit entry in the icon's context
+    menu.
+
+    \section1 Window Class Implementation
+
+    When constructing the editor widget, we first create the various
+    editor elements before we create the actual system tray icon:
+
+    \snippet desktop/systray/window.cpp 0
+
+    We ensure that the application responds to user input by
+    connecting most of the editor's input widgets (including the
+    system tray icon) to the application's private slots. But note the
+    visibility checkbox; its \l {QCheckBox::}{toggled()} signal is
+    connected to the \e {icon}'s \l {QSystemTrayIcon::}{setVisible()}
+    function instead.
+
+    \snippet desktop/systray/window.cpp 3
+
+    The \c setIcon() slot is triggered whenever the current index in
+    the icon combobox changes, i.e., whenever the user chooses another
+    icon in the editor. Note that it is also called when the user
+    activates the tray icon with the left mouse button, triggering the
+    icon's \l {QSystemTrayIcon::}{activated()} signal. We will come
+    back to this signal shortly.
+
+    The QSystemTrayIcon::setIcon() function sets the \l
+    {QSystemTrayIcon::}{icon} property that holds the actual system
+    tray icon. On Windows, the system tray icon size is 16x16; on X11,
+    the preferred size is 22x22. The icon will be scaled to the
+    appropriate size as necessary.
+
+    Note that on X11, due to a limitation in the system tray
+    specification, mouse clicks on transparent areas in the icon are
+    propagated to the system tray. If this behavior is unacceptable,
+    we suggest using an icon with no transparency.
+
+    \snippet desktop/systray/window.cpp 4
+
+    Whenever the user activates the system tray icon, it emits its \l
+    {QSystemTrayIcon::}{activated()} signal passing the triggering
+    reason as parameter. QSystemTrayIcon provides the \l
+    {QSystemTrayIcon::}{ActivationReason} enum to describe how the
+    icon was activated.
+
+    In the constructor, we connected our icon's \l
+    {QSystemTrayIcon::}{activated()} signal to our custom \c
+    iconActivated() slot: If the user has clicked the icon using the
+    left mouse button, this function changes the icon image by
+    incrementing the icon combobox's current index, triggering the \c
+    setIcon() slot as mentioned above. If the user activates the icon
+    using the middle mouse button, it calls the custom \c
+    showMessage() slot:
+
+    \snippet desktop/systray/window.cpp 5
+
+    When the \e showMessage() slot is triggered, we first retrieve the
+    message icon depending on the currently chosen message type. The
+    QSystemTrayIcon::MessageIcon enum describes the icon that is shown
+    when a balloon message is displayed. Then we call
+    QSystemTrayIcon's \l {QSystemTrayIcon::}{showMessage()} function
+    to show the message with the title, body, and icon for the time
+    specified in milliseconds.
+
+    OS X users note: The Growl notification system must be
+    installed for QSystemTrayIcon::showMessage() to display messages.
+
+    QSystemTrayIcon also has the corresponding, \l {QSystemTrayIcon::}
+    {messageClicked()} signal, which is emitted when the user clicks a
+    message displayed by \l {QSystemTrayIcon::}{showMessage()}.
+
+    \snippet desktop/systray/window.cpp 6
+
+    In the constructor, we connected the \l
+    {QSystemTrayIcon::}{messageClicked()} signal to our custom \c
+    messageClicked() slot that simply displays a message using the
+    QMessageBox class.
+
+    QMessageBox provides a modal dialog with a short message, an icon,
+    and buttons laid out depending on the current style. It supports
+    four severity levels: "Question", "Information", "Warning" and
+    "Critical". The easiest way to pop up a message box in Qt is to
+    call one of the associated static functions, e.g.,
+    QMessageBox::information().
+
+    As we mentioned earlier, we reimplement a couple of QWidget's
+    virtual functions:
+
+    \snippet desktop/systray/window.cpp 1
+
+    Our reimplementation of the QWidget::setVisible() function updates
+    the tray icon's menu whenever the editor's appearance changes,
+    e.g., when maximizing or minimizing the main application window,
+    before calling the base class implementation.
+
+    \snippet desktop/systray/window.cpp 2
+
+    We have reimplemented the QWidget::closeEvent() event handler to
+    receive widget close events, showing the above message to the
+    users when they are closing the editor window.
+
+    In addition to the functions and slots discussed above, we have
+    also implemented several convenience functions to simplify the
+    constructor: \c createIconGroupBox(), \c createMessageGroupBox(),
+    \c createActions() and \c createTrayIcon(). See the \l
+    {desktop/systray/window.cpp}{window.cpp} file for details.
+*/
diff --git a/examples/widgets/dialogs/classwizard/classwizard.cpp b/examples/widgets/dialogs/classwizard/classwizard.cpp
index c913d7b592..d3e366efe6 100644
--- a/examples/widgets/dialogs/classwizard/classwizard.cpp
+++ b/examples/widgets/dialogs/classwizard/classwizard.cpp
@@ -79,31 +79,31 @@ void ClassWizard::accept()
 
     if (field("comment").toBool()) {
         block += "/*\n";
-        block += "    " + header.toLatin1() + "\n";
+        block += "    " + header.toLatin1() + '\n';
         block += "*/\n";
-        block += "\n";
+        block += '\n';
     }
     if (field("protect").toBool()) {
-        block += "#ifndef " + macroName + "\n";
-        block += "#define " + macroName + "\n";
-        block += "\n";
+        block += "#ifndef " + macroName + '\n';
+        block += "#define " + macroName + '\n';
+        block += '\n';
     }
     if (field("includeBase").toBool()) {
-        block += "#include " + baseInclude + "\n";
-        block += "\n";
+        block += "#include " + baseInclude + '\n';
+        block += '\n';
     }
 
     block += "class " + className;
     if (!baseClass.isEmpty())
         block += " : public " + baseClass;
-    block += "\n";
+    block += '\n';
     block += "{\n";
 
     /* qmake ignore Q_OBJECT */
 
     if (field("qobjectMacro").toBool()) {
         block += "    Q_OBJECT\n";
-        block += "\n";
+        block += '\n';
     }
     block += "public:\n";
 
@@ -115,7 +115,7 @@ void ClassWizard::accept()
         block += "    " + className + "();\n";
         if (field("copyCtor").toBool()) {
             block += "    " + className + "(const " + className + " &other);\n";
-            block += "\n";
+            block += '\n';
             block += "    " + className + " &operator=" + "(const " + className
                      + " &other);\n";
         }
@@ -123,11 +123,11 @@ void ClassWizard::accept()
     block += "};\n";
 
     if (field("protect").toBool()) {
-        block += "\n";
+        block += '\n';
         block += "#endif\n";
     }
 
-    QFile headerFile(outputDir + "/" + header);
+    QFile headerFile(outputDir + '/' + header);
     if (!headerFile.open(QFile::WriteOnly | QFile::Text)) {
         QMessageBox::warning(0, QObject::tr("Simple Wizard"),
                              QObject::tr("Cannot write file %1:\n%2")
@@ -141,12 +141,12 @@ void ClassWizard::accept()
 
     if (field("comment").toBool()) {
         block += "/*\n";
-        block += "    " + implementation.toLatin1() + "\n";
+        block += "    " + implementation.toLatin1() + '\n';
         block += "*/\n";
-        block += "\n";
+        block += '\n';
     }
     block += "#include \"" + header.toLatin1() + "\"\n";
-    block += "\n";
+    block += '\n';
 
     if (field("qobjectCtor").toBool()) {
         block += className + "::" + className + "(QObject *parent)\n";
@@ -171,7 +171,7 @@ void ClassWizard::accept()
             block += "{\n";
             block += "    *this = other;\n";
             block += "}\n";
-            block += "\n";
+            block += '\n';
             block += className + " &" + className + "::operator=(const "
                      + className + " &other)\n";
             block += "{\n";
@@ -183,7 +183,7 @@ void ClassWizard::accept()
         }
     }
 
-    QFile implementationFile(outputDir + "/" + implementation);
+    QFile implementationFile(outputDir + '/' + implementation);
     if (!implementationFile.open(QFile::WriteOnly | QFile::Text)) {
         QMessageBox::warning(0, QObject::tr("Simple Wizard"),
                              QObject::tr("Cannot write file %1:\n%2")
@@ -356,9 +356,9 @@ void CodeStylePage::initializePage()
     if (baseClass.isEmpty()) {
         baseIncludeLineEdit->clear();
     } else if (QRegExp("Q[A-Z].*").exactMatch(baseClass)) {
-        baseIncludeLineEdit->setText("<" + baseClass + ">");
+        baseIncludeLineEdit->setText('<' + baseClass + '>');
     } else {
-        baseIncludeLineEdit->setText("\"" + baseClass.toLower() + ".h\"");
+        baseIncludeLineEdit->setText('"' + baseClass.toLower() + ".h\"");
     }
 }
 //! [16]
diff --git a/examples/widgets/doc/src/codeeditor.qdoc b/examples/widgets/doc/src/codeeditor.qdoc
index 645854a58c..6c9e5921b8 100644
--- a/examples/widgets/doc/src/codeeditor.qdoc
+++ b/examples/widgets/doc/src/codeeditor.qdoc
@@ -192,6 +192,6 @@
     fetched with QTextBlock::userData(). Matching parentheses can be
     highlighted with an extra selection. The "Matching Parentheses
     with QSyntaxHighlighter" article in Qt Quarterly 31 implements
-    this. You find it here: \l{http://doc.qt.digia.com/qq/}.
+    this. You find it here: \l{http://doc.qt.io/archives/qq/}.
 
 */
diff --git a/examples/widgets/doc/src/syntaxhighlighter.qdoc b/examples/widgets/doc/src/syntaxhighlighter.qdoc
index 2b283afe5e..7d33299c81 100644
--- a/examples/widgets/doc/src/syntaxhighlighter.qdoc
+++ b/examples/widgets/doc/src/syntaxhighlighter.qdoc
@@ -248,7 +248,7 @@
     It is possible to implement parenthesis matching with
     QSyntaxHighlighter. The "Matching Parentheses with
     QSyntaxHighlighter" article in Qt Quarterly 31
-    (\l{http://doc.qt.digia.com/qq/}) implements this. We also have
+    (\l{http://doc.qt.io/archives/qq/}) implements this. We also have
     the \l{Code Editor Example}, which shows how to implement line
     numbers and how to highlight the current line.
 
diff --git a/examples/widgets/draganddrop/draggableicons/main.cpp b/examples/widgets/draganddrop/draggableicons/main.cpp
index 165f71dbf7..44b4f848bf 100644
--- a/examples/widgets/draganddrop/draggableicons/main.cpp
+++ b/examples/widgets/draganddrop/draggableicons/main.cpp
@@ -50,11 +50,10 @@ int main(int argc, char *argv[])
     QApplication app(argc, argv);
 
     QWidget mainWidget;
-    QHBoxLayout *horizontalLayout = new QHBoxLayout;
+    QHBoxLayout *horizontalLayout = new QHBoxLayout(&mainWidget);
     horizontalLayout->addWidget(new DragWidget);
     horizontalLayout->addWidget(new DragWidget);
 
-    mainWidget.setLayout(horizontalLayout);
     mainWidget.setWindowTitle(QObject::tr("Draggable Icons"));
     mainWidget.show();
 
diff --git a/examples/widgets/draganddrop/draggabletext/draggabletext.pro b/examples/widgets/draganddrop/draggabletext/draggabletext.pro
index 2815be1613..1add2a270e 100644
--- a/examples/widgets/draganddrop/draggabletext/draggabletext.pro
+++ b/examples/widgets/draganddrop/draggabletext/draggabletext.pro
@@ -1,10 +1,8 @@
 QT += widgets
 
-HEADERS     = draglabel.h \
-              dragwidget.h
+HEADERS     = dragwidget.h
 RESOURCES   = draggabletext.qrc
-SOURCES     = draglabel.cpp \
-              dragwidget.cpp \
+SOURCES     = dragwidget.cpp \
               main.cpp
 
 # install
diff --git a/examples/widgets/draganddrop/draggabletext/draglabel.cpp b/examples/widgets/draganddrop/draggabletext/draglabel.cpp
deleted file mode 100644
index 4e741fb6c8..0000000000
--- a/examples/widgets/draganddrop/draggabletext/draglabel.cpp
+++ /dev/null
@@ -1,49 +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 "draglabel.h"
-
-DragLabel::DragLabel(const QString &text, QWidget *parent)
-    : QLabel(text, parent)
-{
-    setAutoFillBackground(true);
-    setFrameShape(QFrame::Panel);
-    setFrameShadow(QFrame::Raised);
-}
diff --git a/examples/widgets/draganddrop/draggabletext/draglabel.h b/examples/widgets/draganddrop/draggabletext/draglabel.h
deleted file mode 100644
index 8d2c31aa1d..0000000000
--- a/examples/widgets/draganddrop/draggabletext/draglabel.h
+++ /dev/null
@@ -1,58 +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 DRAGLABEL_H
-#define DRAGLABEL_H
-
-#include <QLabel>
-
-QT_BEGIN_NAMESPACE
-class QDragEnterEvent;
-class QDragMoveEvent;
-class QFrame;
-QT_END_NAMESPACE
-
-class DragLabel : public QLabel
-{
-public:
-    DragLabel(const QString &text, QWidget *parent);
-};
-
-#endif // DRAGLABEL_H
diff --git a/examples/widgets/draganddrop/draggabletext/dragwidget.cpp b/examples/widgets/draganddrop/draggabletext/dragwidget.cpp
index 3b8bca3277..36c4df2e43 100644
--- a/examples/widgets/draganddrop/draggabletext/dragwidget.cpp
+++ b/examples/widgets/draganddrop/draggabletext/dragwidget.cpp
@@ -40,13 +40,23 @@
 
 #include <QtWidgets>
 
-#include "draglabel.h"
 #include "dragwidget.h"
 
+static QLabel *createDragLabel(const QString &text, QWidget *parent)
+{
+    QLabel *label = new QLabel(text, parent);
+    label->setAutoFillBackground(true);
+    label->setFrameShape(QFrame::Panel);
+    label->setFrameShadow(QFrame::Raised);
+    return label;
+}
+
+static QString hotSpotMimeDataKey() { return QStringLiteral("application/x-hotspot"); }
+
 DragWidget::DragWidget(QWidget *parent)
     : QWidget(parent)
 {
-    QFile dictionaryFile(":/dictionary/words.txt");
+    QFile dictionaryFile(QStringLiteral(":/dictionary/words.txt"));
     dictionaryFile.open(QIODevice::ReadOnly);
     QTextStream inputStream(&dictionaryFile);
 
@@ -57,7 +67,7 @@ DragWidget::DragWidget(QWidget *parent)
         QString word;
         inputStream >> word;
         if (!word.isEmpty()) {
-            DragLabel *wordLabel = new DragLabel(word, this);
+            QLabel *wordLabel = createDragLabel(word, this);
             wordLabel->move(x, y);
             wordLabel->show();
             wordLabel->setAttribute(Qt::WA_DeleteOnClose);
@@ -69,12 +79,6 @@ DragWidget::DragWidget(QWidget *parent)
         }
     }
 
-    /*
-    QPalette newPalette = palette();
-    newPalette.setColor(QPalette::Window, Qt::white);
-    setPalette(newPalette);
-    */
-
     setAcceptDrops(true);
     setMinimumSize(400, qMax(200, y));
     setWindowTitle(tr("Draggable Text"));
@@ -98,19 +102,19 @@ void DragWidget::dropEvent(QDropEvent *event)
 {
     if (event->mimeData()->hasText()) {
         const QMimeData *mime = event->mimeData();
-        QStringList pieces = mime->text().split(QRegExp("\\s+"),
+        QStringList pieces = mime->text().split(QRegularExpression(QStringLiteral("\\s+")),
                              QString::SkipEmptyParts);
         QPoint position = event->pos();
         QPoint hotSpot;
 
-        QList<QByteArray> hotSpotPos = mime->data("application/x-hotspot").split(' ');
+        QByteArrayList hotSpotPos = mime->data(hotSpotMimeDataKey()).split(' ');
         if (hotSpotPos.size() == 2) {
             hotSpot.setX(hotSpotPos.first().toInt());
             hotSpot.setY(hotSpotPos.last().toInt());
         }
 
-        foreach (QString piece, pieces) {
-            DragLabel *newLabel = new DragLabel(piece, this);
+        foreach (const QString &piece, pieces) {
+            QLabel *newLabel = createDragLabel(piece, this);
             newLabel->move(position - hotSpot);
             newLabel->show();
             newLabel->setAttribute(Qt::WA_DeleteOnClose);
@@ -127,18 +131,15 @@ void DragWidget::dropEvent(QDropEvent *event)
     } else {
         event->ignore();
     }
-    foreach (QObject *child, children()) {
-        if (child->inherits("QWidget")) {
-            QWidget *widget = static_cast<QWidget *>(child);
-            if (!widget->isVisible())
-                widget->deleteLater();
-        }
+    foreach (QWidget *widget, findChildren<QWidget *>()) {
+        if (!widget->isVisible())
+            widget->deleteLater();
     }
 }
 
 void DragWidget::mousePressEvent(QMouseEvent *event)
 {
-    QLabel *child = static_cast<QLabel*>(childAt(event->pos()));
+    QLabel *child = qobject_cast<QLabel*>(childAt(event->pos()));
     if (!child)
         return;
 
@@ -146,8 +147,8 @@ void DragWidget::mousePressEvent(QMouseEvent *event)
 
     QMimeData *mimeData = new QMimeData;
     mimeData->setText(child->text());
-    mimeData->setData("application/x-hotspot",
-                      QByteArray::number(hotSpot.x()) + " " + QByteArray::number(hotSpot.y()));
+    mimeData->setData(hotSpotMimeDataKey(),
+                      QByteArray::number(hotSpot.x()) + ' ' + QByteArray::number(hotSpot.y()));
 
     QPixmap pixmap(child->size());
     child->render(&pixmap);
diff --git a/examples/widgets/draganddrop/dropsite/droparea.cpp b/examples/widgets/draganddrop/dropsite/droparea.cpp
index d3d2bb10ca..0016434cc3 100644
--- a/examples/widgets/draganddrop/dropsite/droparea.cpp
+++ b/examples/widgets/draganddrop/dropsite/droparea.cpp
@@ -92,10 +92,8 @@ void DropArea::dropEvent(QDropEvent *event)
     } else if (mimeData->hasUrls()) {
         QList<QUrl> urlList = mimeData->urls();
         QString text;
-        for (int i = 0; i < urlList.size() && i < 32; ++i) {
-            QString url = urlList.at(i).path();
-            text += url + QString("\n");
-        }
+        for (int i = 0; i < urlList.size() && i < 32; ++i)
+            text += urlList.at(i).path() + QLatin1Char('\n');
         setText(text);
     } else {
         setText(tr("Cannot display data"));
diff --git a/examples/widgets/draganddrop/dropsite/dropsitewindow.cpp b/examples/widgets/draganddrop/dropsite/dropsitewindow.cpp
index 5f0e689fc9..5d48be1c34 100644
--- a/examples/widgets/draganddrop/dropsite/dropsitewindow.cpp
+++ b/examples/widgets/draganddrop/dropsite/dropsitewindow.cpp
@@ -55,8 +55,8 @@ DropSiteWindow::DropSiteWindow()
 
 //! [constructor part2]
     dropArea = new DropArea;
-    connect(dropArea, SIGNAL(changed(const QMimeData*)),
-            this, SLOT(updateFormatsTable(const QMimeData*)));
+    connect(dropArea, &DropArea::changed,
+            this, &DropSiteWindow::updateFormatsTable);
 //! [constructor part2]
 
 //! [constructor part3]
@@ -78,17 +78,16 @@ DropSiteWindow::DropSiteWindow()
     buttonBox->addButton(clearButton, QDialogButtonBox::ActionRole);
     buttonBox->addButton(quitButton, QDialogButtonBox::RejectRole);
 
-    connect(quitButton, SIGNAL(pressed()), this, SLOT(close()));
-    connect(clearButton, SIGNAL(pressed()), dropArea, SLOT(clear()));
+    connect(quitButton, &QAbstractButton::pressed, this, &QWidget::close);
+    connect(clearButton, &QAbstractButton::pressed, dropArea, &DropArea::clear);
 //! [constructor part4]
 
 //! [constructor part5]
-    QVBoxLayout *mainLayout = new QVBoxLayout;
+    QVBoxLayout *mainLayout = new QVBoxLayout(this);
     mainLayout->addWidget(abstractLabel);
     mainLayout->addWidget(dropArea);
     mainLayout->addWidget(formatsTable);
     mainLayout->addWidget(buttonBox);
-    setLayout(mainLayout);
 
     setWindowTitle(tr("Drop Site"));
     setMinimumSize(350, 500);
@@ -112,22 +111,18 @@ void DropSiteWindow::updateFormatsTable(const QMimeData *mimeData)
 
 //! [updateFormatsTable() part3]
         QString text;
-        if (format == "text/plain") {
+        if (format == QLatin1String("text/plain")) {
             text = mimeData->text().simplified();
-        } else if (format == "text/html") {
+        } else if (format == QLatin1String("text/html")) {
             text = mimeData->html().simplified();
-        } else if (format == "text/uri-list") {
+        } else if (format == QLatin1String("text/uri-list")) {
             QList<QUrl> urlList = mimeData->urls();
             for (int i = 0; i < urlList.size() && i < 32; ++i)
-                text.append(urlList[i].toString() + " ");
+                text.append(urlList.at(i).toString() + QLatin1Char(' '));
         } else {
             QByteArray data = mimeData->data(format);
-            for (int i = 0; i < data.size() && i < 32; ++i) {
-                QString hex = QString("%1").arg(uchar(data[i]), 2, 16,
-                                                QChar('0'))
-                                           .toUpper();
-                text.append(hex + " ");
-            }
+            for (int i = 0; i < data.size() && i < 32; ++i)
+                text.append(QStringLiteral("%1 ").arg(uchar(data[i]), 2, 16, QLatin1Char('0')).toUpper());
         }
 //! [updateFormatsTable() part3]
 
diff --git a/examples/widgets/draganddrop/fridgemagnets/dragwidget.cpp b/examples/widgets/draganddrop/fridgemagnets/dragwidget.cpp
index a591a29994..3a9ab5fa76 100644
--- a/examples/widgets/draganddrop/fridgemagnets/dragwidget.cpp
+++ b/examples/widgets/draganddrop/fridgemagnets/dragwidget.cpp
@@ -43,11 +43,13 @@
 
 #include <QtWidgets>
 
+static inline QString fridgetMagnetsMimeType() { return QStringLiteral("application/x-fridgemagnet"); }
+
 //! [0]
 DragWidget::DragWidget(QWidget *parent)
     : QWidget(parent)
 {
-    QFile dictionaryFile(":/dictionary/words.txt");
+    QFile dictionaryFile(QStringLiteral(":/dictionary/words.txt"));
     dictionaryFile.open(QFile::ReadOnly);
     QTextStream inputStream(&dictionaryFile);
 //! [0]
@@ -74,7 +76,6 @@ DragWidget::DragWidget(QWidget *parent)
 //! [1]
 
 //! [2]
-    //Fridge magnets is used for demoing Qt on S60 and themed backgrounds look better than white
     QPalette newPalette = palette();
     newPalette.setColor(QPalette::Window, Qt::white);
     setPalette(newPalette);
@@ -90,7 +91,7 @@ DragWidget::DragWidget(QWidget *parent)
 void DragWidget::dragEnterEvent(QDragEnterEvent *event)
 {
 //! [4] //! [5]
-    if (event->mimeData()->hasFormat("application/x-fridgemagnet")) {
+    if (event->mimeData()->hasFormat(fridgetMagnetsMimeType())) {
         if (children().contains(event->source())) {
             event->setDropAction(Qt::MoveAction);
             event->accept();
@@ -110,7 +111,7 @@ void DragWidget::dragEnterEvent(QDragEnterEvent *event)
 //! [8]
 void DragWidget::dragMoveEvent(QDragMoveEvent *event)
 {
-    if (event->mimeData()->hasFormat("application/x-fridgemagnet")) {
+    if (event->mimeData()->hasFormat(fridgetMagnetsMimeType())) {
         if (children().contains(event->source())) {
             event->setDropAction(Qt::MoveAction);
             event->accept();
@@ -128,10 +129,10 @@ void DragWidget::dragMoveEvent(QDragMoveEvent *event)
 //! [9]
 void DragWidget::dropEvent(QDropEvent *event)
 {
-    if (event->mimeData()->hasFormat("application/x-fridgemagnet")) {
+    if (event->mimeData()->hasFormat(fridgetMagnetsMimeType())) {
         const QMimeData *mime = event->mimeData();
 //! [9] //! [10]
-        QByteArray itemData = mime->data("application/x-fridgemagnet");
+        QByteArray itemData = mime->data(fridgetMagnetsMimeType());
         QDataStream dataStream(&itemData, QIODevice::ReadOnly);
 
         QString text;
@@ -152,11 +153,11 @@ void DragWidget::dropEvent(QDropEvent *event)
         }
 //! [11] //! [12]
     } else if (event->mimeData()->hasText()) {
-        QStringList pieces = event->mimeData()->text().split(QRegExp("\\s+"),
+        QStringList pieces = event->mimeData()->text().split(QRegularExpression(QStringLiteral("\\s+")),
                              QString::SkipEmptyParts);
         QPoint position = event->pos();
 
-        foreach (QString piece, pieces) {
+        foreach (const QString &piece, pieces) {
             DragLabel *newLabel = new DragLabel(piece, this);
             newLabel->move(position);
             newLabel->show();
@@ -190,7 +191,7 @@ void DragWidget::mousePressEvent(QMouseEvent *event)
 
 //! [15]
     QMimeData *mimeData = new QMimeData;
-    mimeData->setData("application/x-fridgemagnet", itemData);
+    mimeData->setData(fridgetMagnetsMimeType(), itemData);
     mimeData->setText(child->labelText());
 //! [15]
 
diff --git a/examples/widgets/draganddrop/fridgemagnets/main.cpp b/examples/widgets/draganddrop/fridgemagnets/main.cpp
index edff4486d6..a52ff8cabd 100644
--- a/examples/widgets/draganddrop/fridgemagnets/main.cpp
+++ b/examples/widgets/draganddrop/fridgemagnets/main.cpp
@@ -52,7 +52,7 @@ int main(int argc, char *argv[])
 #endif
     DragWidget window;
 
-    bool smallScreen = QApplication::arguments().contains("-small-screen");
+    bool smallScreen = QApplication::arguments().contains(QStringLiteral("-small-screen"));
     if (smallScreen)
         window.showFullScreen();
     else
diff --git a/examples/widgets/draganddrop/puzzle/main.cpp b/examples/widgets/draganddrop/puzzle/main.cpp
index 706ebe4d70..e8ecbe37db 100644
--- a/examples/widgets/draganddrop/puzzle/main.cpp
+++ b/examples/widgets/draganddrop/puzzle/main.cpp
@@ -48,7 +48,7 @@ int main(int argc, char *argv[])
 
     QApplication app(argc, argv);
     MainWindow window;
-    window.openImage(":/images/example.jpg");
+    window.loadImage(QStringLiteral(":/images/example.jpg"));
     window.show();
     return app.exec();
 }
diff --git a/examples/widgets/draganddrop/puzzle/mainwindow.cpp b/examples/widgets/draganddrop/puzzle/mainwindow.cpp
index 0fbdfc3f8d..48e79946e7 100644
--- a/examples/widgets/draganddrop/puzzle/mainwindow.cpp
+++ b/examples/widgets/draganddrop/puzzle/mainwindow.cpp
@@ -55,26 +55,27 @@ MainWindow::MainWindow(QWidget *parent)
     setWindowTitle(tr("Puzzle"));
 }
 
-void MainWindow::openImage(const QString &path)
+void MainWindow::openImage()
 {
-    QString fileName = path;
+    const QString fileName =
+        QFileDialog::getOpenFileName(this, tr("Open Image"), QString(),
+                                     tr("Image Files (*.png *.jpg *.bmp)"));
 
-    if (fileName.isNull()) {
-        fileName = QFileDialog::getOpenFileName(this,
-            tr("Open Image"), "", "Image Files (*.png *.jpg *.bmp)");
-    }
+    if (!fileName.isEmpty())
+        loadImage(fileName);
+}
 
-    if (!fileName.isEmpty()) {
-        QPixmap newImage;
-        if (!newImage.load(fileName)) {
-            QMessageBox::warning(this, tr("Open Image"),
-                                  tr("The image file could not be loaded."),
-                                  QMessageBox::Cancel);
-            return;
-        }
-        puzzleImage = newImage;
-        setupPuzzle();
+void MainWindow::loadImage(const QString &fileName)
+{
+    QPixmap newImage;
+    if (!newImage.load(fileName)) {
+        QMessageBox::warning(this, tr("Open Image"),
+                             tr("The image file could not be loaded."),
+                             QMessageBox::Close);
+        return;
     }
+    puzzleImage = newImage;
+    setupPuzzle();
 }
 
 void MainWindow::setCompleted()
@@ -120,19 +121,15 @@ void MainWindow::setupMenus()
 {
     QMenu *fileMenu = menuBar()->addMenu(tr("&File"));
 
-    QAction *openAction = fileMenu->addAction(tr("&Open..."));
+    QAction *openAction = fileMenu->addAction(tr("&Open..."), this, &MainWindow::openImage);
     openAction->setShortcuts(QKeySequence::Open);
 
-    QAction *exitAction = fileMenu->addAction(tr("E&xit"));
+    QAction *exitAction = fileMenu->addAction(tr("E&xit"), qApp, &QCoreApplication::quit);
     exitAction->setShortcuts(QKeySequence::Quit);
 
     QMenu *gameMenu = menuBar()->addMenu(tr("&Game"));
 
-    QAction *restartAction = gameMenu->addAction(tr("&Restart"));
-
-    connect(openAction, SIGNAL(triggered()), this, SLOT(openImage()));
-    connect(exitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
-    connect(restartAction, SIGNAL(triggered()), this, SLOT(setupPuzzle()));
+    gameMenu->addAction(tr("&Restart"), this, &MainWindow::setupPuzzle);
 }
 
 void MainWindow::setupWidgets()
@@ -144,8 +141,8 @@ void MainWindow::setupWidgets()
     piecesList = new PiecesList(puzzleWidget->pieceSize(), this);
 
 
-    connect(puzzleWidget, SIGNAL(puzzleCompleted()),
-            this, SLOT(setCompleted()), Qt::QueuedConnection);
+    connect(puzzleWidget, &PuzzleWidget::puzzleCompleted,
+            this, &MainWindow::setCompleted, Qt::QueuedConnection);
 
     frameLayout->addWidget(piecesList);
     frameLayout->addWidget(puzzleWidget);
diff --git a/examples/widgets/draganddrop/puzzle/mainwindow.h b/examples/widgets/draganddrop/puzzle/mainwindow.h
index 093a14472e..b5b7d0d903 100644
--- a/examples/widgets/draganddrop/puzzle/mainwindow.h
+++ b/examples/widgets/draganddrop/puzzle/mainwindow.h
@@ -56,9 +56,10 @@ class MainWindow : public QMainWindow
 
 public:
     MainWindow(QWidget *parent = 0);
+    void loadImage(const QString &path);
 
 public slots:
-    void openImage(const QString &path = QString());
+    void openImage();
     void setupPuzzle();
 
 private slots:
diff --git a/examples/widgets/draganddrop/puzzle/pieceslist.cpp b/examples/widgets/draganddrop/puzzle/pieceslist.cpp
index e60fd0a9ff..fb27aa2304 100644
--- a/examples/widgets/draganddrop/puzzle/pieceslist.cpp
+++ b/examples/widgets/draganddrop/puzzle/pieceslist.cpp
@@ -57,7 +57,7 @@ PiecesList::PiecesList(int pieceSize, QWidget *parent)
 
 void PiecesList::dragEnterEvent(QDragEnterEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece"))
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType()))
         event->accept();
     else
         event->ignore();
@@ -65,7 +65,7 @@ void PiecesList::dragEnterEvent(QDragEnterEvent *event)
 
 void PiecesList::dragMoveEvent(QDragMoveEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece")) {
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())) {
         event->setDropAction(Qt::MoveAction);
         event->accept();
     } else {
@@ -75,8 +75,8 @@ void PiecesList::dragMoveEvent(QDragMoveEvent *event)
 
 void PiecesList::dropEvent(QDropEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece")) {
-        QByteArray pieceData = event->mimeData()->data("image/x-puzzle-piece");
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())) {
+        QByteArray pieceData = event->mimeData()->data(PiecesList::puzzleMimeType());
         QDataStream dataStream(&pieceData, QIODevice::ReadOnly);
         QPixmap pixmap;
         QPoint location;
@@ -112,7 +112,7 @@ void PiecesList::startDrag(Qt::DropActions /*supportedActions*/)
     dataStream << pixmap << location;
 
     QMimeData *mimeData = new QMimeData;
-    mimeData->setData("image/x-puzzle-piece", itemData);
+    mimeData->setData(PiecesList::puzzleMimeType(), itemData);
 
     QDrag *drag = new QDrag(this);
     drag->setMimeData(mimeData);
diff --git a/examples/widgets/draganddrop/puzzle/pieceslist.h b/examples/widgets/draganddrop/puzzle/pieceslist.h
index 83c1ad8285..07fa504f41 100644
--- a/examples/widgets/draganddrop/puzzle/pieceslist.h
+++ b/examples/widgets/draganddrop/puzzle/pieceslist.h
@@ -51,6 +51,8 @@ public:
     explicit PiecesList(int pieceSize, QWidget *parent = 0);
     void addPiece(QPixmap pixmap, QPoint location);
 
+    static QString puzzleMimeType() { return QStringLiteral("image/x-puzzle-piece"); }
+
 protected:
     void dragEnterEvent(QDragEnterEvent *event) Q_DECL_OVERRIDE;
     void dragMoveEvent(QDragMoveEvent *event) Q_DECL_OVERRIDE;
diff --git a/examples/widgets/draganddrop/puzzle/puzzlewidget.cpp b/examples/widgets/draganddrop/puzzle/puzzlewidget.cpp
index 69c0cbf0cc..29052da4fb 100644
--- a/examples/widgets/draganddrop/puzzle/puzzlewidget.cpp
+++ b/examples/widgets/draganddrop/puzzle/puzzlewidget.cpp
@@ -39,6 +39,7 @@
 ****************************************************************************/
 
 #include "puzzlewidget.h"
+#include "pieceslist.h"
 
 #include <QDrag>
 #include <QDragEnterEvent>
@@ -65,7 +66,7 @@ void PuzzleWidget::clear()
 
 void PuzzleWidget::dragEnterEvent(QDragEnterEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece"))
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType()))
         event->accept();
     else
         event->ignore();
@@ -83,8 +84,8 @@ void PuzzleWidget::dragMoveEvent(QDragMoveEvent *event)
 {
     QRect updateRect = highlightedRect.united(targetSquare(event->pos()));
 
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece")
-        && findPiece(targetSquare(event->pos())) == -1) {
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())
+        && pieceRects.indexOf(targetSquare(event->pos())) == -1) {
 
         highlightedRect = targetSquare(event->pos());
         event->setDropAction(Qt::MoveAction);
@@ -99,10 +100,10 @@ void PuzzleWidget::dragMoveEvent(QDragMoveEvent *event)
 
 void PuzzleWidget::dropEvent(QDropEvent *event)
 {
-    if (event->mimeData()->hasFormat("image/x-puzzle-piece")
-        && findPiece(targetSquare(event->pos())) == -1) {
+    if (event->mimeData()->hasFormat(PiecesList::puzzleMimeType())
+        && pieceRects.indexOf(targetSquare(event->pos())) == -1) {
 
-        QByteArray pieceData = event->mimeData()->data("image/x-puzzle-piece");
+        QByteArray pieceData = event->mimeData()->data(PiecesList::puzzleMimeType());
         QDataStream dataStream(&pieceData, QIODevice::ReadOnly);
         QRect square = targetSquare(event->pos());
         QPixmap pixmap;
@@ -130,19 +131,10 @@ void PuzzleWidget::dropEvent(QDropEvent *event)
     }
 }
 
-int PuzzleWidget::findPiece(const QRect &pieceRect) const
-{
-    for (int i = 0; i < pieceRects.size(); ++i) {
-        if (pieceRect == pieceRects[i])
-            return i;
-    }
-    return -1;
-}
-
 void PuzzleWidget::mousePressEvent(QMouseEvent *event)
 {
     QRect square = targetSquare(event->pos());
-    int found = findPiece(square);
+    int found = pieceRects.indexOf(square);
 
     if (found == -1)
         return;
@@ -164,7 +156,7 @@ void PuzzleWidget::mousePressEvent(QMouseEvent *event)
     dataStream << pixmap << location;
 
     QMimeData *mimeData = new QMimeData;
-    mimeData->setData("image/x-puzzle-piece", itemData);
+    mimeData->setData(PiecesList::puzzleMimeType(), itemData);
 
     QDrag *drag = new QDrag(this);
     drag->setMimeData(mimeData);
diff --git a/examples/widgets/draganddrop/puzzle/puzzlewidget.h b/examples/widgets/draganddrop/puzzle/puzzlewidget.h
index 6bf264b5e0..eb8a3a29f9 100644
--- a/examples/widgets/draganddrop/puzzle/puzzlewidget.h
+++ b/examples/widgets/draganddrop/puzzle/puzzlewidget.h
@@ -75,7 +75,6 @@ protected:
     void paintEvent(QPaintEvent *event) Q_DECL_OVERRIDE;
 
 private:
-    int findPiece(const QRect &pieceRect) const;
     const QRect targetSquare(const QPoint &position) const;
 
     QList<QPixmap> piecePixmaps;
diff --git a/examples/widgets/gestures/imagegestures/imagewidget.cpp b/examples/widgets/gestures/imagegestures/imagewidget.cpp
index 440eb783c1..28c715c688 100644
--- a/examples/widgets/gestures/imagegestures/imagewidget.cpp
+++ b/examples/widgets/gestures/imagegestures/imagewidget.cpp
@@ -200,7 +200,6 @@ void ImageWidget::openDirectory(const QString &path)
 
 QImage ImageWidget::loadImage(const QString &fileName)
 {
-    qDebug() << position << files << fileName;
     QImageReader reader(fileName);
     reader.setAutoTransform(true);
     qCDebug(lcExample) << "loading" << QDir::toNativeSeparators(fileName) << position << '/' << files.size();
@@ -230,7 +229,7 @@ void ImageWidget::goNextImage()
         prevImage = currentImage;
         currentImage = nextImage;
         if (position+1 < files.size())
-            nextImage = loadImage(path+QLatin1String("/")+files.at(position+1));
+            nextImage = loadImage(path + QLatin1Char('/') + files.at(position+1));
         else
             nextImage = QImage();
     }
@@ -247,7 +246,7 @@ void ImageWidget::goPrevImage()
         nextImage = currentImage;
         currentImage = prevImage;
         if (position > 0)
-            prevImage = loadImage(path+QLatin1String("/")+files.at(position-1));
+            prevImage = loadImage(path + QLatin1Char('/') + files.at(position-1));
         else
             prevImage = QImage();
     }
@@ -277,12 +276,12 @@ void ImageWidget::goToImage(int index)
     position = index;
 
     if (index > 0)
-        prevImage = loadImage(path+QLatin1String("/")+files.at(position-1));
+        prevImage = loadImage(path + QLatin1Char('/') + files.at(position-1));
     else
         prevImage = QImage();
-    currentImage = loadImage(path+QLatin1String("/")+files.at(position));
+    currentImage = loadImage(path + QLatin1Char('/') + files.at(position));
     if (position+1 < files.size())
-        nextImage = loadImage(path+QLatin1String("/")+files.at(position+1));
+        nextImage = loadImage(path + QLatin1Char('/') + files.at(position+1));
     else
         nextImage = QImage();
     update();
diff --git a/examples/widgets/gestures/imagegestures/imagewidget.h b/examples/widgets/gestures/imagegestures/imagewidget.h
index 1629516c0a..71ad2792d0 100644
--- a/examples/widgets/gestures/imagegestures/imagewidget.h
+++ b/examples/widgets/gestures/imagegestures/imagewidget.h
@@ -77,7 +77,6 @@ private:
     void swipeTriggered(QSwipeGesture*);
 //! [class definition begin]
 
-    void updateImage();
     QImage loadImage(const QString &fileName);
     void loadImage();
     void goNextImage();
diff --git a/examples/widgets/gestures/imagegestures/mainwidget.h b/examples/widgets/gestures/imagegestures/mainwidget.h
index 20e32d1afb..e37baa398c 100644
--- a/examples/widgets/gestures/imagegestures/mainwidget.h
+++ b/examples/widgets/gestures/imagegestures/mainwidget.h
@@ -57,8 +57,6 @@ public slots:
     void openDirectory(const QString &path);
 
 private:
-    bool loadImage(const QString &fileName);
-
     ImageWidget *imageWidget;
 };
 
diff --git a/examples/widgets/graphicsview/boxes/scene.cpp b/examples/widgets/graphicsview/boxes/scene.cpp
index 48bdcb9d93..c9691704cb 100644
--- a/examples/widgets/graphicsview/boxes/scene.cpp
+++ b/examples/widgets/graphicsview/boxes/scene.cpp
@@ -319,9 +319,9 @@ RenderOptionsDialog::RenderOptionsDialog()
                 while (++it != tokens.end()) {
                     m_parameterNames << name;
                     if (!singleElement) {
-                        m_parameterNames.back() += "[";
+                        m_parameterNames.back() += '[';
                         m_parameterNames.back() += counter + counterPos;
-                        m_parameterNames.back() += "]";
+                        m_parameterNames.back() += ']';
                         int j = 8; // position of last digit
                         ++counter[j];
                         while (j > 0 && counter[j] > '9') {
diff --git a/examples/widgets/itemviews/chart/mainwindow.cpp b/examples/widgets/itemviews/chart/mainwindow.cpp
index 9a3b372233..a148c3036d 100644
--- a/examples/widgets/itemviews/chart/mainwindow.cpp
+++ b/examples/widgets/itemviews/chart/mainwindow.cpp
@@ -124,7 +124,7 @@ void MainWindow::loadFile(const QString &fileName)
         if (!line.isEmpty()) {
             model->insertRows(row, 1, QModelIndex());
 
-            QStringList pieces = line.split(",", QString::SkipEmptyParts);
+            QStringList pieces = line.split(',', QString::SkipEmptyParts);
             model->setData(model->index(row, 0, QModelIndex()),
                            pieces.value(0));
             model->setData(model->index(row, 1, QModelIndex()),
diff --git a/examples/widgets/itemviews/editabletreemodel/treemodel.cpp b/examples/widgets/itemviews/editabletreemodel/treemodel.cpp
index 2903dd7d38..2b12c142cd 100644
--- a/examples/widgets/itemviews/editabletreemodel/treemodel.cpp
+++ b/examples/widgets/itemviews/editabletreemodel/treemodel.cpp
@@ -246,7 +246,7 @@ void TreeModel::setupModelData(const QStringList &lines, TreeItem *parent)
     while (number < lines.count()) {
         int position = 0;
         while (position < lines[number].length()) {
-            if (lines[number].mid(position, 1) != " ")
+            if (lines[number].at(position) != ' ')
                 break;
             ++position;
         }
diff --git a/examples/widgets/itemviews/frozencolumn/main.cpp b/examples/widgets/itemviews/frozencolumn/main.cpp
index cfdf57135c..1292a7f403 100644
--- a/examples/widgets/itemviews/frozencolumn/main.cpp
+++ b/examples/widgets/itemviews/frozencolumn/main.cpp
@@ -54,15 +54,15 @@ int main(int argc, char* argv[])
     QFile file(":/grades.txt");
     if (file.open(QFile::ReadOnly)) {
         QString line = file.readLine(200);
-        QStringList list = line.simplified().split(",");
+        QStringList list = line.simplified().split(',');
         model->setHorizontalHeaderLabels(list);
 
         int row = 0;
         QStandardItem *newItem = 0;
         while (file.canReadLine()) {
             line = file.readLine(200);
-            if (!line.startsWith("#") && line.contains(",")) {
-                list= line.simplified().split(",");
+            if (!line.startsWith('#') && line.contains(',')) {
+                list = line.simplified().split(',');
                 for (int col = 0; col < list.length(); ++col){
                     newItem = new QStandardItem(list.at(col));
                     model->setItem(row, col, newItem);
diff --git a/examples/widgets/itemviews/interview/model.cpp b/examples/widgets/itemviews/interview/model.cpp
index ba65144cfa..efbb67486b 100644
--- a/examples/widgets/itemviews/interview/model.cpp
+++ b/examples/widgets/itemviews/interview/model.cpp
@@ -88,7 +88,7 @@ QVariant Model::data(const QModelIndex &index, int role) const
     if (!index.isValid())
         return QVariant();
     if (role == Qt::DisplayRole)
-        return QVariant("Item " + QString::number(index.row()) + ":" + QString::number(index.column()));
+        return QVariant("Item " + QString::number(index.row()) + ':' + QString::number(index.column()));
     if (role == Qt::DecorationRole) {
         if (index.column() == 0)
             return iconProvider.icon(QFileIconProvider::Folder);
diff --git a/examples/widgets/itemviews/simpledommodel/dommodel.cpp b/examples/widgets/itemviews/simpledommodel/dommodel.cpp
index f6450abc8b..531957f60b 100644
--- a/examples/widgets/itemviews/simpledommodel/dommodel.cpp
+++ b/examples/widgets/itemviews/simpledommodel/dommodel.cpp
@@ -88,7 +88,7 @@ QVariant DomModel::data(const QModelIndex &index, int role) const
             for (int i = 0; i < attributeMap.count(); ++i) {
                 QDomNode attribute = attributeMap.item(i);
                 attributes << attribute.nodeName() + "=\""
-                              +attribute.nodeValue() + "\"";
+                              +attribute.nodeValue() + '"';
             }
             return attributes.join(' ');
         case 2:
diff --git a/examples/widgets/itemviews/simpletreemodel/treemodel.cpp b/examples/widgets/itemviews/simpletreemodel/treemodel.cpp
index aaa4685b27..f5cd1a160e 100644
--- a/examples/widgets/itemviews/simpletreemodel/treemodel.cpp
+++ b/examples/widgets/itemviews/simpletreemodel/treemodel.cpp
@@ -180,7 +180,7 @@ void TreeModel::setupModelData(const QStringList &lines, TreeItem *parent)
     while (number < lines.count()) {
         int position = 0;
         while (position < lines[number].length()) {
-            if (lines[number].mid(position, 1) != " ")
+            if (lines[number].at(position) != ' ')
                 break;
             position++;
         }
diff --git a/examples/widgets/tools/regexp/regexpdialog.cpp b/examples/widgets/tools/regexp/regexpdialog.cpp
index 32df8a4b91..8ed1e790fb 100644
--- a/examples/widgets/tools/regexp/regexpdialog.cpp
+++ b/examples/widgets/tools/regexp/regexpdialog.cpp
@@ -153,8 +153,8 @@ void RegExpDialog::refresh()
     QString escaped = pattern;
     escaped.replace("\\", "\\\\");
     escaped.replace("\"", "\\\"");
-    escaped.prepend("\"");
-    escaped.append("\"");
+    escaped.prepend('"');
+    escaped.append('"');
     escapedPatternLineEdit->setText(escaped);
 
     QRegExp rx(pattern);
diff --git a/examples/widgets/tools/regularexpression/regularexpressiondialog.cpp b/examples/widgets/tools/regularexpression/regularexpressiondialog.cpp
index d40b4b325d..6cddc1f6c1 100644
--- a/examples/widgets/tools/regularexpression/regularexpressiondialog.cpp
+++ b/examples/widgets/tools/regularexpression/regularexpressiondialog.cpp
@@ -111,8 +111,8 @@ void RegularExpressionDialog::refresh()
     QString escaped = pattern;
     escaped.replace(QLatin1String("\\"), QLatin1String("\\\\"));
     escaped.replace(QLatin1String("\""), QLatin1String("\\\""));
-    escaped.prepend(QLatin1String("\""));
-    escaped.append(QLatin1String("\""));
+    escaped.prepend(QLatin1Char('"'));
+    escaped.append(QLatin1Char('"'));
     escapedPatternLineEdit->setText(escaped);
 
     QRegularExpression rx(pattern);
diff --git a/examples/widgets/tools/settingseditor/variantdelegate.cpp b/examples/widgets/tools/settingseditor/variantdelegate.cpp
index f68082c660..fe2391762b 100644
--- a/examples/widgets/tools/settingseditor/variantdelegate.cpp
+++ b/examples/widgets/tools/settingseditor/variantdelegate.cpp
@@ -60,7 +60,7 @@ VariantDelegate::VariantDelegate(QObject *parent)
 
     dateExp.setPattern("([0-9]{,4})-([0-9]{,2})-([0-9]{,2})");
     timeExp.setPattern("([0-9]{,2}):([0-9]{,2}):([0-9]{,2})");
-    dateTimeExp.setPattern(dateExp.pattern() + "T" + timeExp.pattern());
+    dateTimeExp.setPattern(dateExp.pattern() + 'T' + timeExp.pattern());
 }
 
 void VariantDelegate::paint(QPainter *painter,
@@ -217,7 +217,7 @@ void VariantDelegate::setModelData(QWidget *editor, QAbstractItemModel *model,
         value = QSize(sizeExp.cap(1).toInt(), sizeExp.cap(2).toInt());
         break;
     case QVariant::StringList:
-        value = text.split(",");
+        value = text.split(',');
         break;
     case QVariant::Time:
         {
diff --git a/examples/widgets/tutorials/addressbook/part7/addressbook.cpp b/examples/widgets/tutorials/addressbook/part7/addressbook.cpp
index 6764423d71..2953ecd7de 100644
--- a/examples/widgets/tutorials/addressbook/part7/addressbook.cpp
+++ b/examples/widgets/tutorials/addressbook/part7/addressbook.cpp
@@ -421,23 +421,23 @@ void AddressBook::exportAsVCard()
 //! [export function part2]
 
 //! [export function part3]
-    out << "BEGIN:VCARD" << "\n";
-    out << "VERSION:2.1" << "\n";
-    out << "N:" << lastName << ";" << firstName << "\n";
+    out << "BEGIN:VCARD" << '\n';
+    out << "VERSION:2.1" << '\n';
+    out << "N:" << lastName << ';' << firstName << '\n';
 
     if (!nameList.isEmpty())
-       out << "FN:" << nameList.join(' ') << "\n";
+       out << "FN:" << nameList.join(' ') << '\n';
     else
-       out << "FN:" << firstName << "\n";
+       out << "FN:" << firstName << '\n';
 //! [export function part3]
 
 //! [export function part4]
     address.replace(";", "\\;", Qt::CaseInsensitive);
-    address.replace("\n", ";", Qt::CaseInsensitive);
+    address.replace('\n', ";", Qt::CaseInsensitive);
     address.replace(",", " ", Qt::CaseInsensitive);
 
-    out << "ADR;HOME:;" << address << "\n";
-    out << "END:VCARD" << "\n";
+    out << "ADR;HOME:;" << address << '\n';
+    out << "END:VCARD" << '\n';
 
     QMessageBox::information(this, tr("Export Successful"),
         tr("\"%1\" has been exported as a vCard.").arg(name));
diff --git a/examples/widgets/tutorials/modelview/5_edit/mymodel.cpp b/examples/widgets/tutorials/modelview/5_edit/mymodel.cpp
index 5eb677bb9d..c04c77772f 100644
--- a/examples/widgets/tutorials/modelview/5_edit/mymodel.cpp
+++ b/examples/widgets/tutorials/modelview/5_edit/mymodel.cpp
@@ -83,7 +83,7 @@ bool MyModel::setData(const QModelIndex & index, const QVariant & value, int rol
         {
             for(int col= 0; col < COLS; col++)
             {
-                result += m_gridData[row][col] + " ";
+                result += m_gridData[row][col] + ' ';
             }
         }
         emit editCompleted( result );
diff --git a/examples/widgets/widgets/calculator/calculator.cpp b/examples/widgets/widgets/calculator/calculator.cpp
index e76011ee0d..87061a9868 100644
--- a/examples/widgets/widgets/calculator/calculator.cpp
+++ b/examples/widgets/widgets/calculator/calculator.cpp
@@ -276,7 +276,7 @@ void Calculator::pointClicked()
 {
     if (waitingForOperand)
         display->setText("0");
-    if (!display->text().contains("."))
+    if (!display->text().contains('.'))
         display->setText(display->text() + tr("."));
     waitingForOperand = false;
 }
diff --git a/examples/widgets/widgets/stylesheet/mainwindow.cpp b/examples/widgets/widgets/stylesheet/mainwindow.cpp
index a49c06dfd2..6d84897c77 100644
--- a/examples/widgets/widgets/stylesheet/mainwindow.cpp
+++ b/examples/widgets/widgets/stylesheet/mainwindow.cpp
@@ -67,7 +67,7 @@ void MainWindow::on_aboutAction_triggered()
 {
     QMessageBox::about(this, tr("About Style sheet"),
         tr("The <b>Style Sheet</b> example shows how widgets can be styled "
-           "using <a href=\"http://doc.qt.digia.com/4.5/stylesheet.html\">Qt "
+           "using <a href=\"http://doc.qt.io/qt-5/stylesheet.html\">Qt "
            "Style Sheets</a>. Click <b>File|Edit Style Sheet</b> to pop up the "
            "style editor, and either choose an existing style sheet or design "
            "your own."));
diff --git a/examples/xml/htmlinfo/main.cpp b/examples/xml/htmlinfo/main.cpp
index 3869ca5472..1424cfca67 100644
--- a/examples/xml/htmlinfo/main.cpp
+++ b/examples/xml/htmlinfo/main.cpp
@@ -79,7 +79,7 @@ void parseHtmlFile(QTextStream &out, const QString &fileName) {
     }
 //! [2]
 
-    out << "  Title: \"" << title << "\"" << endl
+    out << "  Title: \"" << title << '"' << endl
         << "  Number of paragraphs: " << paragraphCount << endl
         << "  Number of links: " << links.size() << endl
         << "  Showing first few links:" << endl;
diff --git a/examples/xml/saxbookmarks/xbelgenerator.cpp b/examples/xml/saxbookmarks/xbelgenerator.cpp
index 24612c132c..5f1ec62e7e 100644
--- a/examples/xml/saxbookmarks/xbelgenerator.cpp
+++ b/examples/xml/saxbookmarks/xbelgenerator.cpp
@@ -81,8 +81,8 @@ QString XbelGenerator::escapedAttribute(const QString &str)
 {
     QString result = escapedText(str);
     result.replace("\"", "&quot;");
-    result.prepend("\"");
-    result.append("\"");
+    result.prepend(QLatin1Char('"'));
+    result.append(QLatin1Char('"'));
     return result;
 }