/****************************************************************************
**
** Copyright (C) 2020 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.
** $QT_END_LICENSE$
**
****************************************************************************/

/*!
\page qtwidgets-index.html
\title Qt Widgets
\brief A module which provides a set of C++ technologies for building user
interfaces

    The \l {Qt Widgets C++ Classes}{Qt Widgets Module} provides a set of UI
    elements to create classic desktop-style user interfaces. See the
    \l {User Interfaces} overview for more information on using widgets.

    \section1 Widgets

    Widgets are the primary elements for creating user interfaces in Qt.
    \l{The Widget Classes}{Widgets} can display data and status information,
    receive user input, and provide a container for other widgets that
    should be grouped together. A widget that is not embedded in a
    parent widget is called a \l{Window and Dialog Widgets} {window}.

    \image parent-child-widgets.png A parent widget containing various child widgets.

    The QWidget class provides the basic capability to render to the
    screen, and to handle user input events. All UI elements that Qt
    provides are either subclasses of QWidget, or are used in connection
    with a QWidget subclass. Creating custom widgets is done by
    subclassing QWidget or a suitable subclass and reimplementing the
    virtual event handlers.

    \list
    \li \l{Window and Dialog Widgets}
    \li \l{Application Main Window}
    \li \l{Dialog Windows}
    \li \l{Keyboard Focus in Widgets}
    \endlist

    \section1 Styles

    \l{Styles and Style Aware Widgets}{Styles} draw on behalf of
    widgets and encapsulate the look and feel of a GUI. Qt's built-in
    widgets use the QStyle class to perform nearly all of their drawing,
    ensuring that they look exactly like the equivalent native widgets.

    \table
    \row
    \li \image windowsvista-tabwidget.png
    \li \image fusion-tabwidget.png
    \li \image macos-tabwidget.png
    \endtable

    \l{Qt Style Sheets} are a powerful mechanism that allows you to customize the
    appearance of widgets, in addition to what is already possible by subclassing QStyle.


    \section1 Layouts

    \l{Layout Management}{Layouts} are an elegant and flexible way to
    automatically arrange child widgets within their container. Each
    widget reports its size requirements to the layout through the
    \l{QWidget::}{sizeHint} and \l{QWidget::}{sizePolicy} properties,
    and the layout distributes the available space accordingly.

    \table
    \row
    \li \image qgridlayout-with-5-children.png
    \li \image qformlayout-with-6-children.png
    \endtable

    \l {Qt Designer} is a powerful tool for interactively creating and
    arranging widgets in layouts.



    \section1 Model/View Classes

    The \l{Model/View Programming}{model/view} architecture provides classes
    that manage the way data is presented to the user. Data-driven applications
    which use lists and tables are structured to separate the data and view
    using models, views, and delegates.

    \image windows-treeview.png

    \section1 Graphics View

    The \l{Graphics View Framework} is for managing and interacting with a large
    number of custom-made 2D graphical items, and a view widget for visualizing
    the items, with support for zooming and rotation.

    \image graphicsview-items.png

    \include module-use.qdocinc using qt module
    \snippet snippets/CMakeLists.txt cmake_use

    See also the \l {Build with CMake} overview.

    \include module-use.qdocinc building with qmake
    \snippet snippets.pro qmake_use

    \section1 Module Evolution
    \l{Changes to Qt Widgets} lists important changes in the module API
    and functionality that were done for the Qt 6 series of Qt.

    \section1 Licenses

    The Qt Widgets module is available under commercial licenses from \l{The Qt Company}.
    In addition, it is available under free software licenses:
    The \l{GNU Lesser General Public License, version 3}, or
    the \l{GNU General Public License, version 2}.
    See \l{Qt Licensing} for further details.

    \section1 Related Information

        \section2 Tutorials
    \list
        \li \l{Widgets Tutorial}
        \li \l{Getting Started Programming with Qt Widgets}
        \li \l{Creating a Qt Widget Based Application}


        \li \l{Model/View Tutorial}
    \endlist

    \section2 Examples
    \list
        \li \l{Qt Widgets Examples}
        \li \l{Layout Examples}
    \endlist

    \section1 API Reference
    These are links to the API reference materials.

    \list
        \li \l{Qt Widgets C++ Classes}
        \list
            \li \l{Basic Widget Classes}
            \li \l{Advanced Widget Classes}
            \li \l{Abstract Widget Classes}
            \li \l{Organizer Widget Classes}
            \li \l{Graphics View Classes}
            \li \l{Model/View Classes}
            \li \l{Main Window and Related Classes}
            \li \l{Widget Appearance and Style Related Classes}
            \li \l{Layout Classes}
        \endlist
        \li \l{Qt Style Sheets Reference}
    \endlist

*/
