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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
*/