/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the Qt Charts module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:GPL$
** 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 General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
** approved by the KDE Free Qt Foundation. The licenses are as published by
** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

/*!
     \example donutbreakdown
     \title Donut Chart Breakdown Example
     \ingroup qtcharts_examples

     \brief This example shows how to use create a donut breakdown chart using QPieSeries API.
     \image examples_donutbreakdown.png

     \include examples-run.qdocinc

     \section1 Creating Donut Breakdown Charts

     Let's start by defining some data for the chart.

     \snippet donutbreakdown/main.cpp 1

     Then we create a chart where we add the data. Note that this is our own chart derived from QChart.

     \snippet donutbreakdown/main.cpp 2

     Our own chart works in such a way that we create a main series in the constructor we create a main series,
     which aggregates the data provided by the breakdown series. This is the piechart in the center.

     \snippet donutbreakdown/donutbreakdownchart.cpp 1

     When a breakdown series is added the data is used to create a slice in the main series and the
     breakdown series itself is used to create a segment of a donut positioned so that it is aligned
     with the corresponding slice in the main series.

     \snippet donutbreakdown/donutbreakdownchart.cpp 2

     Here's how the start and end angles for the donut segments are calculated.

     \snippet donutbreakdown/donutbreakdownchart.cpp 3

     The legend markers are customized to show the breakdown percentage. The markers for the main level slices are hidden.

     \snippet donutbreakdown/donutbreakdownchart.cpp 4

     Instead the main level slices show the percentage on the label.

     \snippet donutbreakdown/mainslice.cpp 1
     \snippet donutbreakdown/mainslice.cpp 2

     Now that we have our chart defined, we can finally create a QChartView and show the chart.

     \snippet donutbreakdown/main.cpp 3

*/
