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author | Gabriel de Dietrich <gabriel.dietrich-de@nokia.com> | 2012-08-17 13:23:19 +0200 |
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committer | Qt by Nokia <qt-info@nokia.com> | 2012-08-20 12:20:55 +0200 |
commit | 806dda08d685bc5f9ed71dfe8b61f21848d48066 (patch) | |
tree | a63533a1c4a335ae17adc105abb0ae4e62e2f26e /examples/widgets/doc/chart.qdoc | |
parent | 9f942014e31842b512c3198de035d041c59f54a9 (diff) |
Moving .qdoc files under examples/widgets/doc
Updated those .qdoc files to refer to the new relative examples
emplacement. Images and snippets to be moved later.
Also grouped all widgets related examples under widgets.
Change-Id: Ib29696e2d8948524537f53e8dda88f9ee26a597f
Reviewed-by: J-P Nurmi <j-p.nurmi@nokia.com>
Diffstat (limited to 'examples/widgets/doc/chart.qdoc')
-rw-r--r-- | examples/widgets/doc/chart.qdoc | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/examples/widgets/doc/chart.qdoc b/examples/widgets/doc/chart.qdoc new file mode 100644 index 0000000000..44263d1027 --- /dev/null +++ b/examples/widgets/doc/chart.qdoc @@ -0,0 +1,82 @@ +/**************************************************************************** +** +** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies). +** Contact: http://www.qt-project.org/ +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:FDL$ +** GNU Free Documentation License +** Alternatively, this file may be used under the terms of the GNU Free +** Documentation License version 1.3 as published by the Free Software +** Foundation and appearing in the file included in the packaging of +** this file. +** +** Other Usage +** Alternatively, this file may be used in accordance with the terms +** and conditions contained in a signed written agreement between you +** and Nokia. +** +** +** +** +** +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \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. + + \b{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 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 + \li 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. + \li 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 +*/ |