Doc: move notepad example to qtbase and improve it

- Edited gettingstartedqt.qdoc
- update .pro files
- replaced snippet statements by \quotefromfile
- removed second version of notepad.h and notepad.cpp
  that were made only for quoting snippets
  (\quotefromfile reads from the program code)
- show current filename in header of window
- added checking routine on filename in Save method

Task-number: QTBUG-63984
Change-Id: I5298d761763a4dfeb705a1d9b77354be853ada88
Reviewed-by: Topi Reiniö <topi.reinio@qt.io>

examples/widgets/tutorials/gettingstartedqt.qdoc

@@ -0,0 +1,559 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://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 https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://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: https://www.gnu.org/licenses/fdl-1.3.html.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+    \example tutorials/notepad
+    \title Getting Started Programming with Qt Widgets
+    \brief A tutorial for Qt Widgets based on a notepad application
+
+    In this topic, we teach basic Qt knowledge by implementing a simple
+    Notepad application using C++ and the \l{Qt Widgets} module. The
+    application is a small text editor which allows you to create a text
+    file, save it, print it,
+    or reopen and edit it again. You can also set the font to be used.
+
+    \image notepad1.png "Notepad application"
+
+    You can find the final Notepad source files in the qtdoc repository
+    in the tutorials/notepad directory. You can either fetch
+    the Qt 5 sources from Qt Project or install them as part of Qt 5.
+    The application is also available in the example list of Qt Creator's
+    Welcome mode.
+
+    \section1 Creating the Notepad Project
+
+    Setting up a new project in Qt Creator is aided by a wizard that
+    guides you step-by-step through the project creation process. The
+    wizard prompts you to enter the settings needed for that particular
+    type of project and creates the project for you.
+
+    \image notepad2.png "Qt Creator New File or Project dialog"
+
+    To create the Notepad project, select \b File > \b{New File or
+    Project} > \b Applications > \b {Qt Widgets Application} > \b Choose,
+    and follow the instructions of the wizard. In the
+    \b{Class Information}
+    dialog, type \b Notepad as the class name and select \b QMainWindow
+    as the base class.
+
+    \image notepad3.png "Class Information Dialog"
+
+    The \b {Qt Widgets Application} wizard creates a project that contains
+    a main source file and a set of files that specify a user interface
+    (Notepad widget):
+
+    \list
+        \li notepad.pro - the project file.
+        \li main.cpp - the main source file for the application.
+        \li notepad.cpp - the source file of the notepad class of the
+            Notepad widget.
+        \li notepad.h - the header file of the notepad class for the
+            Notepad widget.
+        \li notepad.ui - the UI form for the Notepad widget.
+    \endlist
+
+    The .cpp, .h, and .ui files come with the necessary boiler plate code
+    for you to be able to build and run the project. The .pro file is
+    complete.
+    We will take a closer look at the file contents in the following
+    sections.
+
+    \b{Learn More}
+
+    \table
+        \header
+            \li About
+            \li Here
+        \row
+            \li Using Qt Creator
+            \li \l{Qt Creator Manual}{Qt Creator}
+        \row
+            \li Creating other kind of applications with Qt Creator
+            \li \l{Qt Creator: Tutorials}{Qt Creator Tutorials}
+    \endtable
+
+
+    \section1 Main Source File
+
+    The wizard generates the following code in the main.cpp file:
+
+    \quotefromfile tutorials/notepad/main.cpp
+    \skipto "notepad.h"
+    \printuntil EditorApp.exec()
+    \printuntil }
+
+    We will go through the code line by line. The following lines include
+    the header files for the Notepad widget and QApplication. All Qt classes
+    have a header file named after them.
+
+    \quotefromfile tutorials/notepad/main.cpp
+    \skipto notepad.h
+    \printuntil QApplication
+
+    The following line defines the main function that is the entry point
+    for all C and C++  based applications:
+
+    \printline main
+
+    The following line creates a QApplication object. This object manages
+    application-wide resources and is necessary to run any Qt program
+    that uses Qt Widgets. It constructs an application object with \c argc
+    command line arguments run in \c argv. (For GUI applications that
+    do not use Qt Widgets, you can use QGuiApplication instead.)
+
+    \skipuntil {
+    \printuntil QApplication
+
+    The following line creates the Notepad object. This is the object for
+    which the wizard created the class and the UI file. The user interface
+    contains visual elements that are called \c widgets in Qt. Examples
+    of widgets are text edits, scroll bars, labels, and radio buttons. A
+    widget can also be a container for other widgets; a dialog or a main
+    application window, for example.
+
+    \printline Notepad
+
+    The following line shows the Notepad widget on the screen in its own
+    window. Widgets can also function as containers. An example of this
+    is QMainWindow which often contains several types of widgets. Widgets
+    are not visible by default; the function \l{QWidget::}{show()} makes
+    the widget visible.
+
+    \printline Editor.show
+
+    The following line makes the QApplication enter its event loop. When
+    a Qt application is running, events are generated and sent to the
+    widgets of the application. Examples of events are mouse presses
+    and key strokes.
+
+    \printline EditorApp.exec
+
+    \b{Learn More}
+
+    \table
+        \header
+            \li About
+            \li Here
+        \row
+            \li Widgets and Window Geometry
+            \li \l{Window and Dialog Widgets}
+        \row
+            \li Events and event handling
+            \li \l{The Event System}
+    \endtable
+
+    \section1 Designing a UI
+
+    The wizard generates a user interface definition in XML format: notepad.ui.
+    When you open the notepad.ui file in Qt Creator, it automatically
+    opens in the integrated Qt Designer.
+
+    When you build the application, Qt Creator launches the Qt
+    \l{User Interface Compiler (uic)} that reads the .ui file and creates
+    a corresponding C++ header file, ui_notepad.h.
+
+    \section2 Using Qt Designer
+
+    The wizard creates an application that uses a QMainWindow. It has
+    its own layout to which you can add a menu bar, dock widgets, toolbars,
+    and a status bar. The center area can be occupied by any kind of widget.
+    The wizard places the Notepad widget there.
+
+    To add widgets in Qt Designer:
+
+    \list 1
+        \li In the Qt Creator \b Editor mode, double-click the notepad.ui
+            file in the \b Projects view to launch the file in the integrated
+            Qt Designer.
+        \li Drag and drop widgets Text Edit (QTextEdit) to the form.
+        \li Press \b {Ctrl+A} (or \b {Cmd+A}) to select the widgets and click
+            \b {Lay out Vertically} (or press \b {Ctrl+L}) to apply a vertical
+            layout (QVBoxLayout).
+        \li Press \b {Ctrl+S} (or \b {Cmd+S}) to save your changes.
+    \endlist
+
+    The UI now looks as follows in Qt Designer:
+
+    \image notepad4.png
+
+    You can view the generated XML file in the code editor:
+
+    \quotefromfile tutorials/notepad/notepad.ui
+
+    \printuntil QMenuBar
+    \dots
+
+    The following line contains the XML declaration, which specifies the
+    XML version and character encoding used in the document:
+
+    \code
+    <?xml version="1.0" encoding="UTF-8"?>
+    \endcode
+
+    The rest of the file specifies an \c ui element that defines a
+    Notepad widget:
+
+    \code
+    <ui version="4.0">
+    \endcode
+
+    The UI file is used together with the header and source file of the
+    Notepad class. We will look at the rest of the UI file in the later
+    sections.
+
+    \section2 Notepad Header File
+
+    The wizard generated a header file for the Notepad class that has the
+    necessary #includes, a constructor, a destructor, and the Ui object.
+    The file looks as follows:
+
+    \snippet tutorials/notepad/notepad.h all
+
+    The following line includes QMainWindow that provides a main application
+    window:
+
+    \snippet tutorials/notepad/notepad.h 1
+
+    The following lines declare the Notepad class in the Ui namespace,
+    which is the standard namespace for the UI classes generated from
+    .ui files by the \c uic tool:
+
+    \snippet tutorials/notepad/notepad.h 2
+
+    The class declaration contains the \c Q_OBJECT macro. It must come
+    first in the class definition, and declares our class as a QObject.
+    Naturally, it must also inherit from QObject. A QObject adds several
+    abilities to a normal C++ class. Notably, the class name and slot
+    names can be queried at runtime. It is also possible to query a slot's
+    parameter types and invoke it.
+
+    \snippet tutorials/notepad/notepad.h 3
+
+    The following lines declare a constructor that has a default argument
+    called \c parent.
+    The value 0 indicates that the widget has no parent (it is a top-level
+    widget).
+
+    \snippet tutorials/notepad/notepad.h 4
+
+    The following line declares a virtual destructor to free the resources
+    that were acquired by the object during its life-cycle. According to
+    the C++ naming convention, destructors have the same name as the class
+    they are associated with, prefixed with a tilde (~). In QObject,
+    destructors are virtual to ensure that the destructors of derived
+    classes are invoked properly when an object is deleted through a
+    pointer-to-base-class.
+
+    \snippet tutorials/notepad/notepad.h 5
+
+    The following lines declare a member variable which is a pointer to
+    the Notepad UI class. A member variable is associated with a specific
+    class, and accessible for all its methods.
+
+    \snippet tutorials/notepad/notepad.h 6
+
+    \section2 Notepad Source File
+
+    The source file that the wizard generated for the Notepad class looks
+    as follows:
+
+    \quotefromfile tutorials/notepad/notepad.cpp
+    \skipto notepad.h
+    \printuntil ui->textEdit->setFont(font)
+    \printuntil }
+
+    The following lines include the Notepad class header file that was
+    generated by the wizard and the UI header file that was generated
+    by the \c uic tool:
+
+    \quotefromfile tutorials/notepad/notepad.cpp
+    \skipto notepad.h
+    \printuntil ui_notepad
+
+    The following line  defines the \c {Notepad} constructor:
+
+    \skipto Notepad::Notepad
+    \printline Notepad::Notepad
+
+    The following line  calls the QMainWindow constructor, which is
+    the base class for the Notepad class:
+
+    \printline QMainWindow
+
+    The following line  creates the UI class instance and assigns it to
+    the \c ui member:
+
+    \printline ui(new
+
+    The following line sets up the UI:
+
+    \quotefromfile tutorials/notepad/notepad.cpp
+    \skipto ui->setupUi
+    \printline ui->setupUi(this)
+
+    In the destructor, we delete the \c ui:
+
+    \skipto Notepad::~Notepad
+    \printuntil }
+
+    In order to have the text edit field occupy the whole screen, we add
+    \c setCentralWidget to the main window.
+
+    \quotefromfile tutorials/notepad/notepad.cpp
+    \skipto Notepad::Notepad(QWidget *parent)
+    \printuntil }
+
+    \section2 Project File
+
+    The wizard generates the following project file, \c {notepad.pro}, for
+    us:
+
+    \quotefile tutorials/notepad/notepad.pro
+
+    The project file specifies the application name and the \c qmake
+    template to use for generating the project, as well as the source,
+    header, and UI files included in the project.
+
+    You could also use \c qmake's \c -project option to generate the \.pro
+    file. Although, in that case, you have to remember to add the line
+    \c{QT += widgets} to the generated file in order to link against the
+    Qt Widgets Module.
+
+    \b{Learn More}
+
+    \table
+        \header
+            \li About
+            \li Here
+        \row
+            \li Using Qt Designer
+            \li \l{Qt Designer Manual}
+        \row
+            \li Layouts
+            \li \l{Layout Management},
+               \l{Widgets and Layouts},
+               \l{Layout Examples}
+        \row
+            \li The widgets that come with Qt
+            \li \l{Qt Widget Gallery}
+        \row
+            \li Main windows and main window classes
+            \li \l{Application Main Window},
+               \l{Main Window Examples}
+        \row
+            \li QObjects and the Qt Object model (This is essential to
+                understand Qt)
+            \li \l{Object Model}
+        \row
+            \li qmake and the Qt build system
+            \li \l{qmake Manual}
+    \endtable
+
+    \section1 Adding User Interaction
+
+
+    To add functionality to the editor, we start by adding menu items
+    and buttons on a toolbar.
+
+    Click on "Type Here", and add the options New, Open, Save, Save as,
+    Print and Exit. This creates 5 lines in the Action Editor below.
+    To connect the actions to slots, right-click an action and select
+    Go to slot > triggered(), and complete the code for that given slot.
+
+    If we also want to add the actions to a toolbar, we can assign an
+    icon to each QAction, and then drag the QAction to the toolbar. You
+    assign an icon by entering an icon name in the Icon property of the
+    action concerned. When the QAction has been dragged to the toolbar,
+    clicking the icon will launch the associated slot.
+
+    Complete the method \c on_actionNew_triggered():
+
+    \quotefromfile tutorials/notepad/notepad.cpp
+    \skipto on_actionNew_triggered()
+    \printuntil }
+
+    \c current_file is a global variable containing the file presently
+    being edited.
+    It is defined in the private part of notepad.h:
+
+    \quotefromfile tutorials/notepad/notepad.h
+    \skipto private:
+    \printuntil currentFile;
+
+    \c clear() clears the text buffer.
+
+    \section2 Opening a file
+
+    In \c notepad.ui, right click on \c actionOpen and select \c {Go to
+    slot}
+
+    Complete method \c on_actionOpen_triggered().
+
+    \quotefromfile tutorials/notepad/notepad.cpp
+    \skipto on_actionOpen_triggered()
+    \printuntil file.close
+    \printuntil }
+
+
+    \c QFileDialog::getOpenFileName opens a dialog enabling you to select
+    a file.  QFile object \c myfile has the selected \c file_name as
+    parameter.  We store the selected file also into the global variable
+    \c current_file for later purposes. We open the file with \c file.open
+    as a readonly text file. If it cannot be opened, a warning is issued,
+    and the program stops.
+
+    We define a QTextStream \c instream for parameter \c myfile.
+    The contents of file \c myfile is copied into QString \a text.
+    \c setText(text) fille the buffer of our editor with \c text.
+
+    \c section2 Saving a file
+
+    We create the method for saving a file in the same way as for
+    \l {Opening a file}, by right clicking on \c actionSave, and
+    selecting \c {Go to Slot}.
+
+    \skipto Notepad::on_actionSave_triggered
+    \printuntil file.close
+    \printuntil }
+
+    QFile object \c myfile is linked to global variable \c current_file,
+    the variable that contains the file we were working with.
+    If we cannot open \c myfile, an error message is issued and the
+    method stops.  We create a QTextStream \c outstream. The contents
+    of the editor buffer is converted to plain text, and then written
+    to \c outstream.
+
+    \section2 Saving a file with \c {Save as}
+
+    \skipto Notepad::on_actionSave_as_triggered
+    \printuntil file.close
+    \printuntil }
+
+    This is the same procedure as for \c {Saving a file}, the only
+    difference being that here you need to enter a new file name for
+    the file to be created.
+
+
+    \section2 Print a File
+
+    If you want to use print functionalities, you need to add
+    \c printsupport to the project file:
+
+    \badcode
+    QT       += printsupport
+    \endcode
+
+    We declare a QPrinter object called \c printer.
+    We launch a printer dialog box and store the selected printer in
+    object \c printer.  If we clicked on \c Cancel and did not select
+    a printer, the methods returns.  The actual printer command is given
+    with \a ui->textEdit->print with our QPrinter object as parameter.
+
+    \section2 Select a Font
+
+    \skipto Notepad::on_actionFont_triggered
+    \printuntil ui->textEdit->setFont
+    \printline }
+
+    We declare a boolean indicating if we did select a font with
+    QFontDialog. If so, we set the font with \c ui->textEdit->setFont(myfont).
+
+    \section2 Copy, Cut, Paste, Undo, and Redo
+
+    If you select some text, and want to copy it to the clipboard,
+    you call the appropriate method of ui->textEdit. The same counts
+    for cut, paste, undo, and redo.
+
+    This table shows the method name to use.
+
+    \table
+    \header
+        \li Task
+        \li Method called
+    \row
+        \li Copy
+        \li ui->textEdit->copy()
+    \row
+        \li Cut
+        \li ui->textEdit->cut()
+    \row
+        \li Paste
+        \li ui->textEdit->paste()
+    \row
+        \li Undo
+        \li ui->textEdit->undo()
+    \row
+        \li Redo
+        \li ui->textEdit->redo()
+    \endtable
+
+    \b{Learn More}
+
+    \table
+        \header
+            \li About
+            \li Here
+        \row
+            \li MDI applications
+            \li QMdiArea,
+               \l{MDI Example}
+        \row
+            \li Files and I/O devices
+            \li QFile, QIODevice
+        \row
+            \li tr() and internationalization
+            \li \l{Qt Linguist Manual},
+               \l{Writing Source Code for Translation},
+               \l{Internationalization with Qt}
+    \endtable
+
+    \section1 Building and Running Notepad
+
+    Now that you have all the necessary files, select \b Build >
+    \b {Build Project Notepad} to build and run the application. Qt
+    Creator uses \c qmake and \c make to create an executable in the
+    directory specified in the build settings of the project and runs
+    it.
+
+    \section2 Building and Running from the Command Line
+
+    To build the application from the command line, switch to the
+    directory in which you have the \c .cpp file of the application
+    and add the project file (suffixed .pro) described earlier. The
+    following shell commands then build the application:
+
+    \badcode
+        qmake
+        make (or nmake on Windows)
+    \endcode
+
+    The commands create an executable in the project directory. The
+    \c qmake tool reads the project file and produces a \c Makefile
+    with instructions on how to build the application.
+    The \c make tool (or the \c nmake tool) then reads the \c Makefile
+    and produces the executable binary.
+*/

examples/widgets/tutorials/notepad/main.cpp

@@ -0,0 +1,61 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     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 "notepad.h"
+#include <QApplication>
+
+int main(int argc, char *argv[])
+{
+    QApplication EditorApp(argc, argv);
+    Notepad Editor;
+    Editor.show();
+
+    return EditorApp.exec();
+}

examples/widgets/tutorials/notepad/notepad.cpp

@@ -0,0 +1,182 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     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 <QFile>
+#include <QFileDialog>
+#include <QTextStream>
+#include <QMessageBox>
+#include <QPrintDialog>
+#include <QPrinter>
+#include <QFont>
+#include <QFontDialog>
+
+#include "notepad.h"
+#include "ui_notepad.h"
+
+Notepad::Notepad(QWidget *parent) :
+    QMainWindow(parent),
+    ui(new Ui::Notepad)
+{
+    ui->setupUi(this);
+    this->setCentralWidget(ui->textEdit);
+}
+
+Notepad::~Notepad()
+{
+    delete ui;
+}
+
+void Notepad::on_actionNew_triggered()
+{
+    currentFile.clear();
+    ui->textEdit->setText(QString());
+}
+
+void Notepad::on_actionOpen_triggered()
+{
+    QString fileName = QFileDialog::getOpenFileName(this, "Open the file");
+    QFile file(fileName);
+    currentFile = fileName;
+    if (!file.open(QIODevice::ReadOnly | QFile::Text)) {
+        QMessageBox::warning(this, "Warning", "Cannot open file: " + file.errorString());
+        return;
+    }
+    setWindowTitle(fileName);
+    QTextStream in(&file);
+    QString text = in.readAll();
+    ui->textEdit->setText(text);
+    file.close();
+}
+
+void Notepad::on_actionSave_triggered()
+{
+    QString fileName;
+    // If we don't have a filename from before, get one.
+    if (currentFile.isEmpty()) {
+        fileName = QFileDialog::getSaveFileName(this, "Save");
+        currentFile = fileName;
+    } else {
+        fileName = currentFile;
+    }
+    QFile file(fileName);
+    if (!file.open(QIODevice::WriteOnly | QFile::Text)) {
+        QMessageBox::warning(this, "Warning", "Cannot save file: " + file.errorString());
+        return;
+    }
+    setWindowTitle(fileName);
+    QTextStream out(&file);
+    QString text = ui->textEdit->toPlainText();
+    out << text;
+    file.close();
+}
+
+void Notepad::on_actionSave_as_triggered()
+{
+    QString fileName = QFileDialog::getSaveFileName(this, "Save as");
+    QFile file(fileName);
+
+    if (!file.open(QFile::WriteOnly | QFile::Text)) {
+        QMessageBox::warning(this, "Warning", "Cannot save file: " + file.errorString());
+        return;
+    }
+    currentFile = fileName;
+    setWindowTitle(fileName);
+    QTextStream out(&file);
+    QString text = ui->textEdit->toPlainText();
+    out << text;
+    file.close();
+}
+
+void Notepad::on_actionPrint_triggered()
+{
+    QPrinter printDev;
+    QPrintDialog dialog(&printDev, this);
+    if (dialog.exec() == QDialog::Rejected)
+        return;
+    ui->textEdit->print(&printDev);
+}
+
+void Notepad::on_actionExit_triggered()
+{
+    QCoreApplication::quit();
+}
+
+void Notepad::on_actionCopy_triggered()
+{
+    ui->textEdit->copy();
+}
+
+void Notepad::on_actionCut_triggered()
+{
+    ui->textEdit->cut();
+}
+
+void Notepad::on_actionPaste_triggered()
+{
+    ui->textEdit->paste();
+}
+
+void Notepad::on_actionUndo_triggered()
+{
+     ui->textEdit->undo();
+}
+
+void Notepad::on_actionRedo_triggered()
+{
+    ui->textEdit->redo();
+}
+
+void Notepad::on_actionFont_triggered()
+{
+    bool fontSelected;
+    QFont font = QFontDialog::getFont(&fontSelected, this);
+    if (fontSelected)
+        ui->textEdit->setFont(font);
+}

examples/widgets/tutorials/notepad/notepad.h

@@ -0,0 +1,114 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:BSD$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** BSD License Usage
+** Alternatively, you may use this file under the terms of the BSD license
+** as follows:
+**
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+**   * Redistributions of source code must retain the above copyright
+**     notice, this list of conditions and the following disclaimer.
+**   * Redistributions in binary form must reproduce the above copyright
+**     notice, this list of conditions and the following disclaimer in
+**     the documentation and/or other materials provided with the
+**     distribution.
+**   * Neither the name of The Qt Company Ltd nor the names of its
+**     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 NOTEPAD_H
+#define NOTEPAD_H
+
+//! [all]
+//! [1]
+#include <QMainWindow>
+//! [1]
+
+//! [2]
+QT_BEGIN_NAMESPACE
+namespace Ui {
+class Notepad;
+}
+QT_END_NAMESPACE
+//! [2]
+
+//! [3]
+class Notepad : public QMainWindow
+{
+    Q_OBJECT
+//! [3]
+
+//! [4]
+public:
+    explicit Notepad(QWidget *parent = 0);
+//! [4]
+//! [5]
+    ~Notepad();
+//! [5]
+
+private slots:
+    void on_actionNew_triggered();
+
+    void on_actionOpen_triggered();
+
+    void on_actionSave_triggered();
+
+    void on_actionSave_as_triggered();
+
+    void on_actionPrint_triggered();
+
+    void on_actionExit_triggered();
+
+    void on_actionCopy_triggered();
+
+    void on_actionCut_triggered();
+
+    void on_actionPaste_triggered();
+
+    void on_actionUndo_triggered();
+
+    void on_actionRedo_triggered();
+
+    void on_actionFont_triggered();
+
+//! [6]
+private:
+    Ui::Notepad *ui;
+    QString currentFile;
+//! [6]
+};
+//! [all]
+
+#endif // NOTEPAD_H

examples/widgets/tutorials/notepad/notepad.pro

@@ -0,0 +1,20 @@
+TEMPLATE = app
+TARGET = notepad
+
+QT += printsupport
+
+SOURCES += \
+    main.cpp\
+    notepad.cpp
+
+HEADERS += notepad.h
+
+FORMS += notepad.ui
+
+RESOURCES += \
+    notepad.qrc
+
+# install
+target.path = $$[QT_INSTALL_EXAMPLES]/widgets/tutorials/notepad
+INSTALLS += target
+

examples/widgets/tutorials/notepad/notepad.qrc

@@ -0,0 +1,19 @@
+<RCC>
+    <qresource prefix="/">
+        <file>images/copy.png</file>
+        <file>images/create.png</file>
+        <file>images/cut.png</file>
+        <file>images/edit_redo.png</file>
+        <file>images/edit_undo.png</file>
+        <file>images/exit.png</file>
+        <file>images/font.png</file>
+        <file>images/info.png</file>
+        <file>images/new.png</file>
+        <file>images/open.png</file>
+        <file>images/paste.png</file>
+        <file>images/pencil.png</file>
+        <file>images/print.png</file>
+        <file>images/save.png</file>
+        <file>images/save_as.png</file>
+    </qresource>
+</RCC>

examples/widgets/tutorials/notepad/notepad.ui

@@ -0,0 +1,196 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>Notepad</class>
+ <widget class="QMainWindow" name="Notepad">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>524</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Notepad</string>
+  </property>
+  <widget class="QWidget" name="centralWidget">
+   <layout class="QVBoxLayout" name="verticalLayout">
+    <item>
+     <widget class="QTextEdit" name="textEdit"/>
+    </item>
+   </layout>
+  </widget>
+  <widget class="QMenuBar" name="menuBar">
+   <property name="geometry">
+    <rect>
+     <x>0</x>
+     <y>0</y>
+     <width>524</width>
+     <height>25</height>
+    </rect>
+   </property>
+   <widget class="QMenu" name="menuFile">
+    <property name="title">
+     <string>File</string>
+    </property>
+    <addaction name="actionNew"/>
+    <addaction name="actionOpen"/>
+    <addaction name="actionSave"/>
+    <addaction name="actionSave_as"/>
+    <addaction name="actionPrint"/>
+    <addaction name="separator"/>
+    <addaction name="actionExit"/>
+   </widget>
+   <widget class="QMenu" name="menuEdit">
+    <property name="title">
+     <string>Edit</string>
+    </property>
+    <addaction name="actionCopy"/>
+    <addaction name="actionCut"/>
+    <addaction name="actionPaste"/>
+    <addaction name="separator"/>
+    <addaction name="actionUndo"/>
+    <addaction name="actionRedo"/>
+    <addaction name="actionFont"/>
+   </widget>
+   <addaction name="menuFile"/>
+   <addaction name="menuEdit"/>
+  </widget>
+  <widget class="QToolBar" name="mainToolBar">
+   <attribute name="toolBarArea">
+    <enum>TopToolBarArea</enum>
+   </attribute>
+   <attribute name="toolBarBreak">
+    <bool>false</bool>
+   </attribute>
+   <addaction name="actionNew"/>
+   <addaction name="actionOpen"/>
+   <addaction name="actionSave"/>
+   <addaction name="actionSave_as"/>
+   <addaction name="actionPrint"/>
+   <addaction name="separator"/>
+   <addaction name="actionCopy"/>
+   <addaction name="actionCut"/>
+   <addaction name="actionPaste"/>
+   <addaction name="actionUndo"/>
+   <addaction name="actionRedo"/>
+   <addaction name="actionFont"/>
+   <addaction name="separator"/>
+   <addaction name="actionExit"/>
+  </widget>
+  <widget class="QStatusBar" name="statusBar"/>
+  <action name="actionNew">
+   <property name="icon">
+    <iconset resource="notepad.qrc">
+     <normaloff>:/images/new.png</normaloff>:/images/new.png</iconset>
+   </property>
+   <property name="text">
+    <string>New</string>
+   </property>
+  </action>
+  <action name="actionOpen">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/open.png</normaloff>:/images/open.png</iconset>
+   </property>
+   <property name="text">
+    <string>Open</string>
+   </property>
+  </action>
+  <action name="actionSave">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/save.png</normaloff>:/images/save.png</iconset>
+   </property>
+   <property name="text">
+    <string>Save</string>
+   </property>
+  </action>
+  <action name="actionSave_as">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/save_as.png</normaloff>:/images/save_as.png</iconset>
+   </property>
+   <property name="text">
+    <string>Save as</string>
+   </property>
+  </action>
+  <action name="actionPrint">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/print.png</normaloff>:/images/print.png</iconset>
+   </property>
+   <property name="text">
+    <string>Print</string>
+   </property>
+  </action>
+  <action name="actionExit">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/exit.png</normaloff>:/images/exit.png</iconset>
+   </property>
+   <property name="text">
+    <string>Exit</string>
+   </property>
+  </action>
+  <action name="actionCopy">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/copy.png</normaloff>:/images/copy.png</iconset>
+   </property>
+   <property name="text">
+    <string>Copy</string>
+   </property>
+  </action>
+  <action name="actionCut">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/cut.png</normaloff>:/images/cut.png</iconset>
+   </property>
+   <property name="text">
+    <string>Cut</string>
+   </property>
+  </action>
+  <action name="actionPaste">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/paste.png</normaloff>:/images/paste.png</iconset>
+   </property>
+   <property name="text">
+    <string>Paste</string>
+   </property>
+  </action>
+  <action name="actionUndo">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/edit_undo.png</normaloff>:/images/edit_undo.png</iconset>
+   </property>
+   <property name="text">
+    <string>Undo</string>
+   </property>
+  </action>
+  <action name="actionRedo">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/edit_redo.png</normaloff>:/images/edit_redo.png</iconset>
+   </property>
+   <property name="text">
+    <string>Redo</string>
+   </property>
+  </action>
+  <action name="actionFont">
+   <property name="icon">
+    <iconset>
+     <normaloff>:/images/font.png</normaloff>:/images/font.png</iconset>
+   </property>
+   <property name="text">
+    <string>Font</string>
+   </property>
+  </action>
+ </widget>
+ <layoutdefault spacing="6" margin="11"/>
+ <resources>
+  <include location="notepad.qrc"/>
+ </resources>
+ <connections/>
+</ui>

examples/widgets/tutorials/tutorials.pro

@@ -1,2 +1,2 @@
 TEMPLATE = subdirs
-SUBDIRS +=  addressbook widgets modelview gettingStarted
+SUBDIRS +=  addressbook widgets modelview gettingStarted notepad