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Diffstat (limited to 'doc/src/snippets/alphachannel.cpp')
-rw-r--r-- | doc/src/snippets/alphachannel.cpp | 114 |
1 files changed, 114 insertions, 0 deletions
diff --git a/doc/src/snippets/alphachannel.cpp b/doc/src/snippets/alphachannel.cpp new file mode 100644 index 0000000..7783271 --- /dev/null +++ b/doc/src/snippets/alphachannel.cpp @@ -0,0 +1,114 @@ +/**************************************************************************** +** +** 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. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#include <qapplication.h> +#include <qlabel.h> +#include <qpixmap.h> +#include <qprinter.h> +#include <qpainter.h> +#include <qfile.h> +#include <qdir.h> +#include <qfileinfo.h> + +#if (QT_VERSION) >= 0x040000 +#include <QtGui> +#include <QtCore> +#endif + +class MyClass : public QWidget +{ +public: + MyClass(QWidget *parent = 0) : QWidget(parent) { } + +protected: + void paintEvent(QPaintEvent *e) + { + /*QRadialGradient rg(50, 50, 50, 50, 50); + rg.setColorAt(0, QColor::fromRgbF(1, 0, 0, 1)); + rg.setColorAt(1, QColor::fromRgbF(0, 0, 0, 0)); + QPainter pmp(&pm); + pmp.fillRect(0, 0, 100, 100, rg); + pmp.end();*/ + + createImage(); + + QPainter p(this); + p.fillRect(rect(), Qt::white); + + p.drawPixmap(0, 0, pixmap); + + p.drawPixmap(100, 0, channelImage); + } + + void createImage() + { +//! [0] + pixmap = QPixmap(100, 100); + pixmap.fill(Qt::transparent); + + QRadialGradient gradient(50, 50, 50, 50, 50); + gradient.setColorAt(0, QColor::fromRgbF(1, 0, 0, 1)); + gradient.setColorAt(1, QColor::fromRgbF(0, 0, 0, 0)); + QPainter painter(&pixmap); + painter.fillRect(0, 0, 100, 100, gradient); + + channelImage = pixmap.alphaChannel(); + update(); +//! [0] + } + + QPixmap channelImage, pixmap; + QSize sizeHint() const { return QSize(500, 500); } +}; + + + +int main(int argc, char **argv) +{ + QApplication app(argc, argv); + + MyClass cl; + cl.show(); + QObject::connect(&app, SIGNAL(lastWindowClosed()), &app, SLOT(quit())); + + int ret = app.exec(); + return ret; +} |