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/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: http://www.qt-project.org/
**
** This file is part of the documentation of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:FDL$
** GNU Free Documentation License
** 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.
**
** Other Usage
** Alternatively, this file may be used in accordance with the terms
** and conditions contained in a signed written agreement between you
** and Nokia.
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/
/*!
\example widgets/groupbox
\title Group Box Example
The Group Box example shows how to use the different kinds of group
boxes in Qt.
Group boxes are container widgets that organize buttons into groups,
both logically and on screen. They manage the interactions between
the user and the application so that you do not have to enforce
simple constraints.
Group boxes are usually used to organize check boxes and radio
buttons into exclusive groups.
\image groupbox-example.png
The Group Boxes example consists of a single \c Window class that
is used to show four group boxes: an exclusive radio button group,
a non-exclusive checkbox group, an exclusive radio button group
with an enabling checkbox, and a group box with normal push buttons.
\section1 Window Class Definition
The \c Window class is a subclass of \c QWidget that is used to
display a number of group boxes. The class definition contains
functions to construct each group box and populate it with different
selections of button widgets:
\snippet examples/widgets/groupbox/window.h 0
In the example, the widget will be used as a top-level window, so
the constructor is defined so that we do not have to specify a parent
widget.
\section1 Window Class Implementation
The constructor creates a grid layout and fills it with each of the
group boxes that are to be displayed:
\snippet examples/widgets/groupbox/window.cpp 0
The functions used to create each group box each return a
QGroupBox to be inserted into the grid layout.
\snippet examples/widgets/groupbox/window.cpp 1
The first group box contains and manages three radio buttons. Since
the group box contains only radio buttons, it is exclusive by
default, so only one radio button can be checked at any given time.
We check the first radio button to ensure that the button group
contains one checked button.
\snippet examples/widgets/groupbox/window.cpp 3
We use a vertical layout within the group box to present the
buttons in the form of a vertical list, and return the group
box to the constructor.
The second group box is itself checkable, providing a convenient
way to disable all the buttons inside it. Initially, it is
unchecked, so the group box itself must be checked before any of
the radio buttons inside can be checked.
\snippet examples/widgets/groupbox/window.cpp 4
The group box contains three exclusive radio buttons, and an
independent checkbox. For consistency, one radio button must be
checked at all times, so we ensure that the first one is initially
checked.
\snippet examples/widgets/groupbox/window.cpp 5
The buttons are arranged in the same way as those in the first
group box.
\snippet examples/widgets/groupbox/window.cpp 6
The third group box is constructed with a "flat" style that is
better suited to certain types of dialog.
\snippet examples/widgets/groupbox/window.cpp 7
This group box contains only checkboxes, so it is non-exclusive by
default. This means that each checkbox can be checked independently
of the others.
\snippet examples/widgets/groupbox/window.cpp 8
Again, we use a vertical layout within the group box to present
the buttons in the form of a vertical list.
\snippet examples/widgets/groupbox/window.cpp 9
The final group box contains only push buttons and, like the
second group box, it is checkable.
\snippet examples/widgets/groupbox/window.cpp 10
We create a normal button, a toggle button, and a flat push button:
\snippet examples/widgets/groupbox/window.cpp 11
Push buttons can be used to display popup menus. We create one, and
attach a simple menu to it:
\snippet examples/widgets/groupbox/window.cpp 12
Finally, we lay out the widgets vertically, and return the group box
that we created:
\snippet examples/widgets/groupbox/window.cpp 13
*/
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