Long live Qt for S60!

9 files changed, 1042 insertions, 0 deletions

diff --git a/doc/src/snippets/separations/finalwidget.cpp b/doc/src/snippets/separations/finalwidget.cpp
new file mode 100644
index 0000000..c6b103a
--- /dev/null
+++ b/doc/src/snippets/separations/finalwidget.cpp
@@ -0,0 +1,127 @@
+/****************************************************************************
+**
+** 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.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*
+finalwidget.cpp
+
+A widget to display an image and a label containing a description.
+*/
+
+#include <QtGui>
+#include "finalwidget.h"
+
+FinalWidget::FinalWidget(QWidget *parent, const QString &name,
+                         const QSize &labelSize)
+    : QFrame(parent)
+{
+    hasImage = false;
+    imageLabel = new QLabel;
+    imageLabel->setFrameShadow(QFrame::Sunken);
+    imageLabel->setFrameShape(QFrame::StyledPanel);
+    imageLabel->setMinimumSize(labelSize);
+    nameLabel = new QLabel(name);
+
+    QVBoxLayout *layout = new QVBoxLayout;
+    layout->addWidget(imageLabel, 1);
+    layout->addWidget(nameLabel, 0);
+    setLayout(layout);
+}
+
+/*!
+    If the mouse moves far enough when the left mouse button is held down,
+    start a drag and drop operation.
+*/
+
+void FinalWidget::mouseMoveEvent(QMouseEvent *event)
+{
+    if (!(event->buttons() & Qt::LeftButton))
+        return;
+    if ((event->pos() - dragStartPosition).manhattanLength()
+         < QApplication::startDragDistance())
+        return;
+    if (!hasImage)
+        return;
+
+    QDrag *drag = new QDrag(this);
+    QMimeData *mimeData = new QMimeData;
+
+//! [0]
+    QByteArray output;
+    QBuffer outputBuffer(&output);
+    outputBuffer.open(QIODevice::WriteOnly);
+    imageLabel->pixmap()->toImage().save(&outputBuffer, "PNG");
+    mimeData->setData("image/png", output);
+//! [0]
+/*
+//! [1]
+    mimeData->setImageData(QVariant(*imageLabel->pixmap()));
+//! [1]
+*/
+    drag->setMimeData(mimeData);
+    drag->setPixmap(imageLabel->pixmap()->scaled(64, 64, Qt::KeepAspectRatio));
+//! [2]
+    drag->setHotSpot(QPoint(drag->pixmap().width()/2,
+                            drag->pixmap().height()));
+//! [2]
+
+    drag->start();
+}
+
+/*!
+    Check for left mouse button presses in order to enable drag and drop.
+*/
+
+void FinalWidget::mousePressEvent(QMouseEvent *event)
+{
+    if (event->button() == Qt::LeftButton)
+        dragStartPosition = event->pos();
+}
+
+const QPixmap* FinalWidget::pixmap() const
+{
+    return imageLabel->pixmap();
+}
+
+void FinalWidget::setPixmap(const QPixmap &pixmap)
+{
+    imageLabel->setPixmap(pixmap);
+    hasImage = true;
+}
diff --git a/doc/src/snippets/separations/finalwidget.h b/doc/src/snippets/separations/finalwidget.h
new file mode 100644
index 0000000..df45fcc
--- /dev/null
+++ b/doc/src/snippets/separations/finalwidget.h
@@ -0,0 +1,78 @@
+/****************************************************************************
+**
+** 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.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef FINALWIDGET_H
+#define FINALWIDGET_H
+
+#include <QFrame>
+#include <QImage>
+#include <QPoint>
+#include <QSize>
+
+class QGridLayout;
+class QLabel;
+class QMouseEvent;
+class QWidget;
+
+class FinalWidget : public QFrame
+{
+    Q_OBJECT
+
+public:
+    FinalWidget(QWidget *parent, const QString &name, const QSize &labelSize);
+    void setPixmap(const QPixmap &pixmap);
+    const QPixmap *pixmap() const;
+
+protected:
+    void mouseMoveEvent(QMouseEvent *event);
+    void mousePressEvent(QMouseEvent *event);
+
+private:
+    void createImage();
+
+    bool hasImage;
+    QImage originalImage;
+    QLabel *imageLabel;
+    QLabel *nameLabel;
+    QPoint dragStartPosition;
+};
+
+#endif
diff --git a/doc/src/snippets/separations/main.cpp b/doc/src/snippets/separations/main.cpp
new file mode 100644
index 0000000..0a859c2
--- /dev/null
+++ b/doc/src/snippets/separations/main.cpp
@@ -0,0 +1,51 @@
+/****************************************************************************
+**
+** 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>
+#include "viewer.h"
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+    Viewer viewer;
+    viewer.show();
+    return app.exec();
+}
diff --git a/doc/src/snippets/separations/screenwidget.cpp b/doc/src/snippets/separations/screenwidget.cpp
new file mode 100644
index 0000000..daa276b
--- /dev/null
+++ b/doc/src/snippets/separations/screenwidget.cpp
@@ -0,0 +1,218 @@
+/****************************************************************************
+**
+** 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.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*
+screenwidget.cpp
+
+A widget to display colour components from an image using independently
+selected colors. Controls are provided to allow the image to be inverted, and
+the color to be selection via a standard dialog. The image is displayed in a
+label widget.
+*/
+
+#include <QApplication>
+#include <QColorDialog>
+#include <QGridLayout>
+#include <QImage>
+#include <QLabel>
+#include <QMenu>
+#include <QMimeData>
+#include <QMouseEvent>
+#include <QPixmap>
+#include <QPushButton>
+#include <QWidget>
+
+#include "screenwidget.h"
+
+/*!
+Initializes the paint color, the mask color (cyan, magenta,
+or yellow), connects the color selector and invert checkbox to functions,
+and creates a two-by-two grid layout.
+*/
+
+ScreenWidget::ScreenWidget(QWidget *parent, QColor initialColor,
+                           const QString &name, Separation mask,
+                           const QSize &labelSize)
+    : QFrame(parent)
+{
+    paintColor = initialColor;
+    maskColor = mask;
+    inverted = false;
+
+    imageLabel = new QLabel;
+    imageLabel->setFrameShadow(QFrame::Sunken);
+    imageLabel->setFrameShape(QFrame::StyledPanel);
+    imageLabel->setMinimumSize(labelSize);
+
+    nameLabel = new QLabel(name);
+    colorButton = new QPushButton(tr("Modify..."));
+    colorButton->setBackgroundRole(QPalette::Button);
+    colorButton->setMinimumSize(32, 32);
+
+    QPalette palette(colorButton->palette());
+    palette.setColor(QPalette::Button, initialColor);
+    colorButton->setPalette(palette);
+
+    invertButton = new QPushButton(tr("Invert"));
+    //invertButton->setToggleButton(true);
+    //invertButton->setOn(inverted);
+    invertButton->setEnabled(false);
+
+    connect(colorButton, SIGNAL(clicked()), this, SLOT(setColor()));
+    connect(invertButton, SIGNAL(clicked()), this, SLOT(invertImage()));
+
+    QGridLayout *gridLayout = new QGridLayout;
+    gridLayout->addWidget(imageLabel, 0, 0, 1, 2);
+    gridLayout->addWidget(nameLabel, 1, 0);
+    gridLayout->addWidget(colorButton, 1, 1);
+    gridLayout->addWidget(invertButton, 2, 1, 1, 1);
+    setLayout(gridLayout);
+}
+
+/*!
+    Creates a new image by separating out the cyan, magenta, or yellow
+    component, depending on the mask color specified in the constructor.
+
+    The amount of the component found in each pixel of the image is used
+    to determine how much of a user-selected ink is used for each pixel
+    in the new image for the label widget.
+*/
+
+void ScreenWidget::createImage()
+{
+    newImage = originalImage.copy();
+
+    // Create CMY components for the ink being used.
+    float cyanInk = (255 - paintColor.red())/255.0;
+    float magentaInk = (255 - paintColor.green())/255.0;
+    float yellowInk = (255 - paintColor.blue())/255.0;
+
+    int (*convert)(QRgb);
+
+    switch (maskColor) {
+        case Cyan:
+            convert = qRed;
+            break;
+        case Magenta:
+            convert = qGreen;
+            break;
+        case Yellow:
+            convert = qBlue;
+            break;
+    }
+
+    for (int y = 0; y < newImage.height(); ++y) {
+        for (int x = 0; x < newImage.width(); ++x) {
+            QRgb p(originalImage.pixel(x, y));
+
+            // Separate the source pixel into its cyan component.
+            int amount;
+
+            if (inverted)
+                amount = convert(p);
+            else
+                amount = 255 - convert(p);
+
+            QColor newColor(
+                255 - qMin(int(amount * cyanInk), 255),
+                255 - qMin(int(amount * magentaInk), 255),
+                255 - qMin(int(amount * yellowInk), 255));
+
+            newImage.setPixel(x, y, newColor.rgb());
+        }
+    }
+
+    imageLabel->setPixmap(QPixmap::fromImage(newImage));
+}
+
+/*!
+    Returns a pointer to the modified image.
+*/
+
+QImage* ScreenWidget::image()
+{
+    return &newImage;
+}
+
+/*!
+    Sets whether the amount of ink applied to the canvas is to be inverted
+    (subtracted from the maximum value) before the ink is applied.
+*/
+
+void ScreenWidget::invertImage()
+{
+    //inverted = invertButton->isOn();
+    inverted = !inverted;
+    createImage();
+    emit imageChanged();
+}
+
+/*!
+    Separate the current image into cyan, magenta, and yellow components.
+    Create a representation of how each component might appear when applied
+    to a blank white piece of paper.
+*/
+
+void ScreenWidget::setColor()
+{
+    QColor newColor = QColorDialog::getColor(paintColor);
+
+    if (newColor.isValid()) {
+        paintColor = newColor;
+        QPalette palette(colorButton->palette());
+        palette.setColor(QPalette::Button, paintColor);
+        colorButton->setPalette(palette);
+        createImage();
+        emit imageChanged();
+    }
+}
+
+/*!
+    Records the original image selected by the user, creates a color
+    separation, and enables the invert image checkbox.
+*/
+
+void ScreenWidget::setImage(QImage &image)
+{
+    originalImage = image;
+    createImage();
+    invertButton->setEnabled(true);
+}
diff --git a/doc/src/snippets/separations/screenwidget.h b/doc/src/snippets/separations/screenwidget.h
new file mode 100644
index 0000000..3371028
--- /dev/null
+++ b/doc/src/snippets/separations/screenwidget.h
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** 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.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef SCREENWIDGET_H
+#define SCREENWIDGET_H
+
+#include <QColor>
+#include <QFrame>
+#include <QImage>
+#include <QSize>
+
+class QGridLayout;
+class QLabel;
+class QPushButton;
+class QWidget;
+
+class ScreenWidget : public QFrame
+{
+    Q_OBJECT
+public:
+    enum Separation { Cyan, Magenta, Yellow };
+
+    ScreenWidget(QWidget *parent, QColor initialColor, const QString &name,
+                 Separation mask, const QSize &labelSize);
+    void setImage(QImage &image);
+    QImage* image();
+
+signals:
+    void imageChanged();
+
+public slots:
+    void setColor();
+    void invertImage();
+
+private:
+    void createImage();
+
+    bool inverted;
+    QColor paintColor;
+    QImage newImage;
+    QImage originalImage;
+    QLabel *imageLabel;
+    QLabel *nameLabel;
+    QPushButton *colorButton;
+    QPushButton *invertButton;
+    Separation maskColor;
+};
+
+#endif
diff --git a/doc/src/snippets/separations/separations.pro b/doc/src/snippets/separations/separations.pro
new file mode 100644
index 0000000..48af2c8
--- /dev/null
+++ b/doc/src/snippets/separations/separations.pro
@@ -0,0 +1,7 @@
+HEADERS     = finalwidget.h \
+              screenwidget.h \
+              viewer.h
+SOURCES     = finalwidget.cpp \
+              main.cpp \
+              screenwidget.cpp \
+              viewer.cpp
diff --git a/doc/src/snippets/separations/separations.qdoc b/doc/src/snippets/separations/separations.qdoc
new file mode 100644
index 0000000..5091352
--- /dev/null
+++ b/doc/src/snippets/separations/separations.qdoc
@@ -0,0 +1,55 @@
+/****************************************************************************
+**
+** 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/separations
+    \title Color Separations Example
+
+    This example enables simple color manipulation of images and demonstrates a
+    number of image-related features of Qt, from per-pixel image manipulation to
+    drag and drop handling of images.
+
+    \image separations-example.png
+
+    The application allows the user to load an image, shown in the top-left
+    part of the main window, and to adjust its color balance by replacing its
+    initial cyan, magenta, and yellow components with different colors.
+*/
diff --git a/doc/src/snippets/separations/viewer.cpp b/doc/src/snippets/separations/viewer.cpp
new file mode 100644
index 0000000..f33be69
--- /dev/null
+++ b/doc/src/snippets/separations/viewer.cpp
@@ -0,0 +1,329 @@
+/****************************************************************************
+**
+** 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.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*
+viewer.cpp
+
+Provides a main window for displaying a user-specified original image
+with three color separations in a grid layout.
+
+A main menu provides entries for selecting files, and adjusting the
+brightness of the separations.
+*/
+
+#include <QtGui>
+
+#include "finalwidget.h"
+#include "screenwidget.h"
+#include "viewer.h"
+
+/*
+    Constructor: initializes a default value for the brightness, creates
+    the main menu entries, and constructs a central widget that contains
+    enough space for images to be displayed.
+*/
+
+Viewer::Viewer()
+{
+    setWindowTitle(tr("QImage Color Separations"));
+
+    brightness = 255;
+
+    createMenus();
+    setCentralWidget(createCentralWidget());
+}
+
+/*
+    Creates a main menu with two entries: a File menu, to allow the image
+    to be selected, and a Brightness menu to allow the brightness of the
+    separations to be changed.
+
+    Initially, the Brightness menu items are disabled, but the first entry in
+    the menu is checked to reflect the default brightness.
+*/
+
+void Viewer::createMenus()
+{
+    fileMenu = new QMenu(tr("&File"), this);
+    brightnessMenu = new QMenu(tr("&Brightness"), this);
+
+    QAction *openAction = fileMenu->addAction(tr("&Open..."));
+    openAction->setShortcut(QKeySequence("Ctrl+O"));
+    saveAction = fileMenu->addAction(tr("&Save..."));
+    saveAction->setShortcut(QKeySequence("Ctrl+S"));
+    saveAction->setEnabled(false);
+    QAction *quitAction = fileMenu->addAction(tr("E&xit"));
+    quitAction->setShortcut(QKeySequence("Ctrl+Q"));
+
+    QAction *noBrightness = brightnessMenu->addAction(tr("&0%"));
+    noBrightness->setCheckable(true);
+    QAction *quarterBrightness = brightnessMenu->addAction(tr("&25%"));
+    quarterBrightness->setCheckable(true);
+    QAction *halfBrightness = brightnessMenu->addAction(tr("&50%"));
+    halfBrightness->setCheckable(true);
+    QAction *threeQuartersBrightness = brightnessMenu->addAction(tr("&75%"));
+    threeQuartersBrightness->setCheckable(true);
+    QAction *fullBrightness = brightnessMenu->addAction(tr("&100%"));
+    fullBrightness->setCheckable(true);
+
+    menuMap[noBrightness] = None;
+    menuMap[quarterBrightness] = Quarter;
+    menuMap[halfBrightness] = Half;
+    menuMap[threeQuartersBrightness] = ThreeQuarters;
+    menuMap[fullBrightness] = Full;
+
+    currentBrightness = fullBrightness;
+    currentBrightness->setChecked(true);
+    brightnessMenu->setEnabled(false);
+
+    menuBar()->addMenu(fileMenu);
+    menuBar()->addMenu(brightnessMenu);
+
+    connect(openAction, SIGNAL(triggered()), this, SLOT(chooseFile()));
+    connect(saveAction, SIGNAL(triggered()), this, SLOT(saveImage()));
+    connect(quitAction, SIGNAL(triggered()), qApp, SLOT(quit()));
+    connect(brightnessMenu, SIGNAL(triggered(QAction *)), this,
+            SLOT(setBrightness(QAction *)));
+}
+
+/*
+    Constructs a central widget for the window consisting of a two-by-two
+    grid of labels, each of which will contain an image. We restrict the
+    size of the labels to 256 pixels, and ensure that the window cannot
+    be resized.
+*/
+
+QFrame* Viewer::createCentralWidget()
+{
+    QFrame* frame = new QFrame(this);
+    grid = new QGridLayout(frame);
+    grid->setSpacing(8);
+    grid->setMargin(4);
+
+    layout()->setSizeConstraint(QLayout::SetFixedSize);
+
+    QSize labelSize(256, 256);
+
+    finalWidget = new FinalWidget(frame, tr("Final image"), labelSize);
+
+    cyanWidget = new ScreenWidget(frame, Qt::cyan, tr("Cyan"),
+                                  ScreenWidget::Cyan, labelSize);
+    magentaWidget = new ScreenWidget(frame, Qt::magenta, tr("Magenta"),
+                                     ScreenWidget::Magenta, labelSize);
+    yellowWidget = new ScreenWidget(frame, Qt::yellow, tr("Yellow"),
+                                    ScreenWidget::Yellow, labelSize);
+
+    connect(cyanWidget, SIGNAL(imageChanged()), this, SLOT(createImage()));
+    connect(magentaWidget, SIGNAL(imageChanged()), this, SLOT(createImage()));
+    connect(yellowWidget, SIGNAL(imageChanged()), this, SLOT(createImage()));
+
+    grid->addWidget(finalWidget, 0, 0, Qt::AlignTop | Qt::AlignHCenter);
+    grid->addWidget(cyanWidget, 0, 1, Qt::AlignTop | Qt::AlignHCenter);
+    grid->addWidget(magentaWidget, 1, 0, Qt::AlignTop | Qt::AlignHCenter);
+    grid->addWidget(yellowWidget, 1, 1, Qt::AlignTop | Qt::AlignHCenter);
+
+    return frame;
+}
+
+/*
+    Provides a dialog window to allow the user to specify an image file.
+    If a file is selected, the appropriate function is called to process
+    and display it.
+*/
+
+void Viewer::chooseFile()
+{
+    QString imageFile = QFileDialog::getOpenFileName(this,
+        tr("Choose an image file to open"), path, tr("Images (*.*)"));
+
+    if (!imageFile.isEmpty()) {
+        openImageFile(imageFile);
+        path = imageFile;
+    }
+}
+
+/*
+    Changes the value of the brightness according to the entry selected in the
+    Brightness menu. The selected entry is checked, and the previously selected
+    entry is unchecked.
+
+    The color separations are updated to use the new value for the brightness.
+*/
+
+void Viewer::setBrightness(QAction *action)
+{
+    if (!menuMap.contains(action) || scaledImage.isNull())
+        return;
+
+    Brightness amount = menuMap[action];
+
+    switch (amount) {
+        case None:
+            brightness = 0; break;
+        case Quarter:
+            brightness = 64; break;
+        case Half:
+            brightness = 128; break;
+        case ThreeQuarters:
+            brightness = 191; break;
+        case Full:
+            brightness = 255; break;
+        default: return;
+    }
+
+    currentBrightness->setChecked(false);
+    currentBrightness = action;
+    currentBrightness->setChecked(true);
+
+    createImage();
+}
+
+/*
+    Load the image from the file given, and create four pixmaps based
+    on the original image.
+
+    The window caption is set, and the Brightness menu enabled if the image file
+    can be loaded.
+*/
+
+void Viewer::openImageFile(QString &imageFile)
+{
+    QImage originalImage;
+
+    if (originalImage.load(imageFile)) {
+        setWindowTitle(imageFile);
+        //menuBar()->setItemEnabled(brightnessMenuId, true);
+        saveAction->setEnabled(true);
+        brightnessMenu->setEnabled(true);
+
+        /* Note: the ScaleMin value may be different for Qt 4. */
+        scaledImage = originalImage.scaled(256, 256, Qt::KeepAspectRatio);
+
+        cyanWidget->setImage(scaledImage);
+        magentaWidget->setImage(scaledImage);
+        yellowWidget->setImage(scaledImage);
+        createImage();
+    }
+    else
+        (void) QMessageBox::warning(this, tr("Cannot open file"),
+            tr("The selected file could not be opened."),
+            QMessageBox::Cancel, QMessageBox::NoButton, QMessageBox::NoButton);
+}
+
+/*
+    Creates an image by combining the contents of the three screens
+    to present a page preview.
+
+    The image associated with each screen is separated into cyan,
+    magenta, and yellow components. We add up the values for each
+    component from the three screen images, and subtract the totals
+    from the maximum value for each corresponding primary color.
+*/
+
+void Viewer::createImage()
+{
+    QImage newImage = scaledImage.copy();
+
+    QImage *image1 = cyanWidget->image();
+    QImage *image2 = magentaWidget->image();
+    QImage *image3 = yellowWidget->image();
+    int darkness = 255 - brightness;
+
+    for (int y = 0; y < newImage.height(); ++y) {
+        for (int x = 0; x < newImage.width(); ++x) {
+
+            // Create three screens, using the quantities of the source
+            // CMY components to determine how much of each of the
+            // inks are to be put on each screen.
+            QRgb p1(image1->pixel(x, y));
+            float cyan1 = 255 - qRed(p1);
+            float magenta1 = 255 - qGreen(p1);
+            float yellow1 = 255 - qBlue(p1);
+
+            QRgb p2(image2->pixel(x, y));
+            float cyan2 = 255 - qRed(p2);
+            float magenta2 = 255 - qGreen(p2);
+            float yellow2 = 255 - qBlue(p2);
+
+            QRgb p3(image3->pixel(x, y));
+            float cyan3 = 255 - qRed(p3);
+            float magenta3 = 255 - qGreen(p3);
+            float yellow3 = 255 - qBlue(p3);
+
+            QColor newColor(
+                qMax(255 - int(cyan1+cyan2+cyan3) - darkness, 0),
+                qMax(255 - int(magenta1+magenta2+magenta3) - darkness, 0),
+                qMax(255 - int(yellow1+yellow2+yellow3) - darkness, 0));
+
+            newImage.setPixel(x, y, newColor.rgb());
+        }
+    }
+
+    finalWidget->setPixmap(QPixmap::fromImage(newImage));
+}
+
+/*
+    Provides a dialog window to allow the user to save the image file.
+*/
+
+void Viewer::saveImage()
+{
+    QString imageFile = QFileDialog::getSaveFileName(this,
+        tr("Choose a filename to save the image"), "", tr("Images (*.png)"));
+
+    QFileInfo info(imageFile);
+
+    if (!info.baseName().isEmpty()) {
+        QString newImageFile = QFileInfo(info.absoluteDir(),
+            info.baseName() + ".png").absoluteFilePath();
+
+        if (!finalWidget->pixmap()->save(newImageFile, "PNG"))
+            (void) QMessageBox::warning(this, tr("Cannot save file"),
+                tr("The file could not be saved."),
+                QMessageBox::Cancel, QMessageBox::NoButton,
+                QMessageBox::NoButton);
+    }
+    else
+        (void) QMessageBox::warning(this, tr("Cannot save file"),
+            tr("Please enter a valid filename."),
+            QMessageBox::Cancel, QMessageBox::NoButton,
+            QMessageBox::NoButton);
+}
diff --git a/doc/src/snippets/separations/viewer.h b/doc/src/snippets/separations/viewer.h
new file mode 100644
index 0000000..148f081
--- /dev/null
+++ b/doc/src/snippets/separations/viewer.h
@@ -0,0 +1,90 @@
+/****************************************************************************
+**
+** 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.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef VIEWER_H
+#define VIEWER_H
+
+#include <QImage>
+#include <QMainWindow>
+#include <QMap>
+
+class QAction;
+class QFrame;
+class QGridLayout;
+class QLabel;
+class QMenu;
+class FinalWidget;
+class ScreenWidget;
+
+class Viewer : public QMainWindow
+{
+    Q_OBJECT
+public:
+    enum Brightness { None, Quarter, Half, ThreeQuarters, Full };
+    Viewer();
+
+public slots:
+    void chooseFile();
+    void setBrightness(QAction *action);
+    void createImage();
+    void saveImage();
+
+private:
+    void createMenus();
+    QFrame *createCentralWidget();
+    void openImageFile(QString &filePath);
+
+    FinalWidget *finalWidget;
+    int brightness;
+    QAction *currentBrightness;
+    QAction *saveAction;
+    QGridLayout *grid;
+    QImage scaledImage;
+    QMap <QAction*,Brightness> menuMap;
+    QMenu *brightnessMenu;
+    QMenu *fileMenu;
+    QString path;
+    ScreenWidget *cyanWidget;
+    ScreenWidget *magentaWidget;
+    ScreenWidget *yellowWidget;
+};
+
+#endif