doc/src/examples/chart.qdoc
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+/****************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
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+** Contact: Nokia Corporation (qt-info@nokia.com)
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+** This file is part of the documentation of the Qt Toolkit.
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+****************************************************************************/
+
+/*!
+    \example itemviews/chart
+    \title Chart Example
+
+    The Chart example shows how to create a custom view for the model/view framework.
+
+    \image chart-example.png
+
+    In this example, the items in a table model are represented as slices in a pie chart,
+    relying on the flexibility of the model/view architecture to handle custom editing
+    and selection features.
+
+    \bold{Note that you only need to create a new view class if your data requires a
+    specialized representation.} You should first consider using a standard QListView,
+    QTableView, or QTreeView with a custom QItemDelegate subclass if you need to
+    represent data in a special way.
+
+    \omit
+    \section1 PieView Class Definition
+
+    The \c PieView class is a subclass of QAbstractItemView. The base class provides
+    much of the functionality required by view classes, so we only need to provide
+    implementations for three public functions: visualRect(), scrollTo(), and
+    indexAt(). However, the view needs to maintain strict control over its look and
+    feel, so we also provide implementations for a number of other functions:
+
+    \snippet examples/itemviews/chart/pieview.h 0
+
+
+
+    \section1 PieView Class Implementation
+
+    The paint event renders the data from the standard item model as a pie chart.
+    We interpret the data in the following way:
+
+    \list
+    \o Column 0 contains data in two different roles:
+       The \l{Qt::ItemDataRole}{DisplayRole} contains a label, and the
+       \l{Qt::ItemDataRole}{DecorationRole} contains the color of the pie slice.
+    \o Column 1 contains a quantity which we will convert to the angular extent of
+       the slice.
+    \endlist
+
+    The figure is always drawn with the chart on the left and the key on
+    the right. This means that we must try and obtain an area that is wider
+    than it is tall. We do this by imposing a particular aspect ratio on
+    the chart and applying it to the available vertical space. This ensures
+    that we always obtain the maximum horizontal space for the aspect ratio
+    used.
+    We also apply fixed size margin around the figure.
+
+    We use logical coordinates to draw the chart and key, and position them
+    on the view using viewports.
+    \endomit
+*/