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++ // Copyright (C) 2024 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only
++
++ /*!
++ \example 2d/quickwidgetgraphs
++ \meta tags {Graphs, PieSeries, Widget, QuickWidget}
++ \examplecategory {Data Visualization}
++
++ \title Graphs 2D in Qt Widgets
++ \ingroup qtgraphs_examples
++ \brief Using Graphs for 2D in a Widget based application.
++
++ Graphs 2D support only Qt Quick applications. This example shows how to
++ display a simple 2D pie graph in a Qt Widgets applications using a
++ \l QQuickWidget.
++
++ \image quickwidgetgraphs-example.png
++ {Pie chart with labeled fruit slices and control buttons}
++
++ \include examples-run.qdocinc
++
++ \section1 Main View
++
++ \list 0
++ \li The \c PieWidget class implements the main view of the demo application.
++ In the \c PieWidget class, instantiate the widgets used to implement the
++ application layout and UI elements.
++
++ \snippet 2d/quickwidgetgraphs/piewidget.cpp 0
++ \dots 0
++
++ \li The \c PieGraph class is used to handle logic for adding and removing
++ slices, and have other functionalities.
++
++ \snippet 2d/quickwidgetgraphs/piewidget.cpp 1
++ \dots 0
++
++ \li Initialize buttons and add them to layout.
++
++ \snippet 2d/quickwidgetgraphs/piewidget.cpp 3
++ \endlist
++
++ \section1 Manipulating Graph data
++
++ The \c PieGraph class implements all the logic for manipulating Graph data in
++ this example.
++
++ \list 0
++ \li In the \c PieGraph class, declare a \c pieSeries property.
++
++ \dots 0
++ \snippet 2d/quickwidgetgraphs/piegraph.h 0
++ \dots 0
++
++ \li Create functions for adding, removing, exploding slices, and clearing
++ pie series.
++
++ \dots 0
++ \quotefromfile 2d/quickwidgetgraphs/piegraph.h
++ \skipto public:
++ \printto explicit PieGraph
++ \dots 0
++ \skipto appendSlice
++ \printto Q_SIGNALS
++ \dots 0
++
++ \li Instantiate a pie series and add several slices in your constructor.
++
++ \dots 0
++ \snippet 2d/quickwidgetgraphs/piegraph.cpp 0
++ \dots 0
++
++ \li The \c appendSlice function creates a \l QPieSlice, sets some of its
++ properties and then appends it to the pie series.
++
++ Notice that even if you have set labels visibility to \c true, this does
++ not work on slices added later to the pie series. You need to set
++ visibility to \c true on creation for every added slice.
++
++ \snippet 2d/quickwidgetgraphs/piegraph.cpp 1
++
++ \li In the \c removeSlice function, call \l QPieSeries::remove().
++
++ \li In the \c explodeSlices function, loop through all slices and set
++ \l QPieSlice::setExploded() to \c true or \c false depending on current
++ state.
++
++ \li In the \c clearSeries function, call \l QPieSeries::clear(). This will
++ delete all slices from your pie series. Note that this function does not
++ delete a pie series itself.
++ \endlist
++
++ \section1 Initializing the GraphsView
++
++ To customize the GraphsView theme, create a custom \l QGraphsTheme.
++
++ \snippet 2d/quickwidgetgraphs/piewidget.cpp 5
++
++ Use \l QQuickWidget::loadFromModule() to load the GraphsView. Initialize its
++ \l {GraphsView::}{theme} and \l {GraphsView::}{seriesList} properties by
++ passing the QGraphsTheme and QPieSeries to
++ \l QQuickWidget::setInitialProperties().
++
++ \snippet 2d/quickwidgetgraphs/piewidget.cpp 2
++ */