| [2] | 1 | /****************************************************************************
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| 2 | **
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| [846] | 3 | ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
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| [561] | 4 | ** All rights reserved.
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| 5 | ** Contact: Nokia Corporation ([email protected])
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| [2] | 6 | **
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| 7 | ** This file is part of the documentation of the Qt Toolkit.
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| 8 | **
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| [846] | 9 | ** $QT_BEGIN_LICENSE:FDL$
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| [2] | 10 | ** Commercial Usage
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| 11 | ** Licensees holding valid Qt Commercial licenses may use this file in
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| 12 | ** accordance with the Qt Commercial License Agreement provided with the
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| [846] | 13 | ** Software or, alternatively, in accordance with the terms contained in a
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| 14 | ** written agreement between you and Nokia.
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| [2] | 15 | **
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| [846] | 16 | ** GNU Free Documentation License
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| 17 | ** Alternatively, this file may be used under the terms of the GNU Free
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| 18 | ** Documentation License version 1.3 as published by the Free Software
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| 19 | ** Foundation and appearing in the file included in the packaging of this
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| 20 | ** file.
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| [2] | 21 | **
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| [561] | 22 | ** If you have questions regarding the use of this file, please contact
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| 23 | ** Nokia at [email protected].
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| [2] | 24 | ** $QT_END_LICENSE$
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| 25 | **
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| 26 | ****************************************************************************/
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| 27 |
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| 28 | /*!
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| 29 | \example widgets/styles
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| 30 | \title Styles Example
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| 31 |
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| 32 | The Styles example illustrates how to create custom widget
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| 33 | drawing styles using Qt, and demonstrates Qt's predefined styles.
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| 34 |
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| 35 | \image styles-enabledwood.png Screenshot of the Styles example
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| 36 |
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| 37 | A style in Qt is a subclass of QStyle or of one of its
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| 38 | subclasses. Styles perform drawing on behalf of widgets. Qt
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| 39 | provides a whole range of predefined styles, either built into
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| 40 | the \l QtGui library or found in plugins. Custom styles are
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| 41 | usually created by subclassing one of Qt's existing style and
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| 42 | reimplementing a few virtual functions.
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| 43 |
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| 44 | In this example, the custom style is called \c NorwegianWoodStyle
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| 45 | and derives from QMotifStyle. Its main features are the wooden
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| 46 | textures used for filling most of the widgets and its round
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| 47 | buttons and comboboxes.
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| 48 |
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| 49 | To implement the style, we use some advanced features provided by
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| 50 | QPainter, such as \l{QPainter::Antialiasing}{antialiasing} (to
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| 51 | obtain smoother button edges), \l{QColor::alpha()}{alpha blending}
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| 52 | (to make the buttons appeared raised or sunken), and
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| 53 | \l{QPainterPath}{painter paths} (to fill the buttons and draw the
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| 54 | outline). We also use many features of QBrush and QPalette.
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| 55 |
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| 56 | The example consists of the following classes:
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| 57 |
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| 58 | \list
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| 59 | \o \c NorwegianWoodStyle inherits from QMotifStyle and implements
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| 60 | the Norwegian Wood style.
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| 61 | \o \c WidgetGallery is a \c QDialog subclass that shows the most
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| 62 | common widgets and allows the user to switch style
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| 63 | dynamically.
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| 64 | \endlist
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| 65 |
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| 66 | \section1 NorwegianWoodStyle Class Definition
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| 67 |
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| 68 | Here's the definition of the \c NorwegianWoodStyle class:
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| 69 |
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| 70 | \snippet examples/widgets/styles/norwegianwoodstyle.h 0
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| 71 |
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| 72 | The public functions are all declared in QStyle (QMotifStyle's
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| 73 | grandparent class) and reimplemented here to override the Motif
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| 74 | look and feel. The private functions are helper functions.
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| 75 |
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| 76 | \section1 NorwegianWoodStyle Class Implementation
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| 77 |
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| 78 | We will now review the implementation of the \c
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| 79 | NorwegianWoodStyle class.
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| 80 |
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| 81 | \snippet examples/widgets/styles/norwegianwoodstyle.cpp 0
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| 82 |
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| 83 | The \c polish() function is reimplemented from QStyle. It takes a
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| 84 | QPalette as a reference and adapts the palette to fit the style.
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| 85 | Most styles don't need to reimplement that function. The
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| 86 | Norwegian Wood style reimplements it to set a "wooden" palette.
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| 87 |
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| 88 | We start by defining a few \l{QColor}s that we'll need. Then we
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| 89 | load two PNG images. The \c : prefix in the file path indicates
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| 90 | that the PNG files are \l{The Qt Resource System}{embedded
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| 91 | resources}.
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| 92 |
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| 93 | \table
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| 94 | \row \o \inlineimage widgets/styles/images/woodbackground.png
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