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diff --git a/doc/src/examples/imagecomposition.qdoc b/doc/src/examples/imagecomposition.qdoc new file mode 100644 index 0000000..8cba805 --- /dev/null +++ b/doc/src/examples/imagecomposition.qdoc @@ -0,0 +1,179 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the documentation of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, this file may be used under the terms of the GNU Lesser +** General Public License version 2.1 as published by the Free Software +** Foundation and appearing in the file LICENSE.LGPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU Lesser General Public License version 2.1 requirements +** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. +** +** In addition, as a special exception, Nokia gives you certain +** additional rights. These rights are described in the Nokia Qt LGPL +** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this +** package. +** +** GNU General Public License Usage +** Alternatively, this file may be used under the terms of the GNU +** General Public License version 3.0 as published by the Free Software +** Foundation and appearing in the file LICENSE.GPL included in the +** packaging of this file. Please review the following information to +** ensure the GNU General Public License version 3.0 requirements will be +** met: http://www.gnu.org/copyleft/gpl.html. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +/*! + \example painting/imagecomposition + \title Image Composition Example + + The Image Composition example lets the user combine images + together using any composition mode supported by QPainter, described + in detail in \l{QPainter#Composition Modes}{Composition Modes}. + + \image imagecomposition-example.png + + \section1 Setting Up The Resource File + + The Image Composition example requires two source images, + \e butterfly.png and \e checker.png that are embedded within + \e imagecomposition.qrc. The file contains the following code: + + \quotefile examples/painting/imagecomposition/imagecomposition.qrc + + For more information on resource files, see \l{The Qt Resource System}. + + \section1 ImageComposer Class Definition + + The \c ImageComposer class is a subclass of QWidget that implements three + private slots, \c chooseSource(), \c chooseDestination(), and + \c recalculateResult(). + + \snippet examples/painting/imagecomposition/imagecomposer.h 0 + + In addition, \c ImageComposer consists of five private functions, + \c addOp(), \c chooseImage(), \c loadImage(), \c currentMode(), and + \c imagePos(), as well as private instances of QToolButton, QComboBox, + QLabel, and QImage. + + \snippet examples/painting/imagecomposition/imagecomposer.h 1 + + \section1 ImageComposer Class Implementation + + We declare a QSize object, \c resultSize, as a static constant with width + and height equal to 200. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 0 + + Within the constructor, we instantiate a QToolButton object, + \c sourceButton and set its \l{QAbstractButton::setIconSize()}{iconSize} + property to \c resultSize. The \c operatorComboBox is instantiated and + then populated using the \c addOp() function. This function accepts a + QPainter::CompositionMode, \a mode, and a QString, \a name, representing + the name of the composition mode. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 1 + + The \c destinationButton is instantiated and its + \l{QAbstractButton::setIconSize()}{iconSize} property is set to + \c resultSize as well. The \l{QLabel}s \c equalLabel and \c resultLabel + are created and \c{resultLabel}'s \l{QWidget::setMinimumWidth()} + {minimumWidth} is set. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 2 + + We connect the following signals to their corresponding slots: + \list + \o \c{sourceButton}'s \l{QPushButton::clicked()}{clicked()} signal is + connected to \c chooseSource(), + \o \c{operatorComboBox}'s \l{QComboBox::activated()}{activated()} + signal is connected to \c recalculateResult(), and + \o \c{destinationButton}'s \l{QToolButton::clicked()}{clicked()} signal + is connected to \c chooseDestination(). + \endlist + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 3 + + A QGridLayout, \c mainLayout, is used to place all the widgets. Note + that \c{mainLayout}'s \l{QLayout::setSizeConstraint()}{sizeConstraint} + property is set to QLayout::SetFixedSize, which means that + \c{ImageComposer}'s size cannot be resized at all. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 4 + + We create a QImage, \c resultImage, and we invoke \c loadImage() twice + to load both the image files in our \e imagecomposition.qrc file. Then, + we set the \l{QWidget::setWindowTitle()}{windowTitle} property to + "Image Composition". + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 5 + + The \c chooseSource() and \c chooseDestination() functions are + convenience functions that invoke \c chooseImage() with specific + parameters. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 6 + \codeline + \snippet examples/painting/imagecomposition/imagecomposer.cpp 7 + + The \c chooseImage() function loads an image of the user's choice, + depending on the \a title, \a image, and \a button. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 10 + + The \c recalculateResult() function is used to calculate amd display the + result of combining the two images together with the user's choice of + composition mode. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 8 + + The \c addOp() function adds an item to the \c operatorComboBox using + \l{QComboBox}'s \l{QComboBox::addItem()}{addItem} function. This function + accepts a QPainter::CompositionMode, \a mode, and a QString, \a name. The + rectangle is filled with Qt::Transparent and both the \c sourceImage and + \c destinationImage are painted, before displaying it on \c resultLabel. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 9 + + The \c loadImage() function paints a transparent background using + \l{QPainter::fillRect()}{fillRect()} and draws \c image in a + centralized position using \l{QPainter::drawImage()}{drawImage()}. + This \c image is then set as the \c{button}'s icon. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 11 + + The \c currentMode() function returns the composition mode currently + selected in \c operatorComboBox. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 12 + + We use the \c imagePos() function to ensure that images loaded onto the + QToolButton objects, \c sourceButton and \c destinationButton, are + centralized. + + \snippet examples/painting/imagecomposition/imagecomposer.cpp 13 + + \section1 The \c main() Function + + The \c main() function instantiates QApplication and \c ImageComposer + and invokes its \l{QWidget::show()}{show()} function. + + \snippet examples/painting/imagecomposition/main.cpp 0 + + */ |