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Documentation for QML custom model demo
Documentation for QML custom model demo

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/*!
\example examples/modeldata
\title Model data example
\subtitle
This example shows how to use QAbstractItemModel derived model as the data for the series.
\image examples_modeldata.png
Let's start by creating an instance of CustomTableModel class.
CustomTableModel class is derived from QAbstractTableModel and it was created for the purpose of this example.
The constructor of this class populates the internal data store of the model with the data that is good for our chart example.
\snippet ../examples/modeldata/tablewidget.cpp 1
We now have a model with data that we would like to display both on the chart and in a QTableView.
First, we create QTableView and tell it use the model as a data source. To make the data cells fill the table view we also change headers resize mode.
\snippet ../examples/modeldata/tablewidget.cpp 2
Now we need QChart instance to display the same data on the chart.
We also enable animations. It makes it easier to see how modifying the model's data affect the chart.
\snippet ../examples/modeldata/tablewidget.cpp 3
First line of the code below creates new line series. Line number two creates an instance of QVXYModelMapper class.
Next two lines specifie that x coordinates are taken from the model's column(Qt::Vertical) with index 0 and the y coordinates are taken from the model's column with index 1.
To create a connection between the series and the model we set both of those objects to QVXYModelMapper.
Finally the series is added to the chart.
\snippet ../examples/modeldata/tablewidget.cpp 4
To show in QTableView which data coresponds with which series this example uses table coloring.
When series is added to the chart it is assigned a color beased on the currently selected theme.
Code below extracts that color from the series and uses it to create colored QTableView.
Coloring of the view is not a part of the QChart functionality.
\snippet ../examples/modeldata/tablewidget.cpp 5
The same operations are done with second series. Notice that for this series different columns of the same model are mapped.
\snippet ../examples/modeldata/tablewidget.cpp 6
\snippet ../examples/modeldata/tablewidget.cpp 7
To avoid setting up the QGraphicsScene we use QChartView class that does it for us. QChart object pointer is used as a parameter of the QChartView constructor.
To make the render look nicer Antialiasing is turned on and the minimum size of the chartView widget is set.
\snippet ../examples/modeldata/tablewidget.cpp 8
Finally we place both widgets in a layout and use the layout as the application layout.
\snippet ../examples/modeldata/tablewidget.cpp 9
Application is ready. Try modifying the data in the table view and see how it affects the chart.
*/