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+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the documentation of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:FDL$
+** 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+/*!
+ \example draganddrop/draggableicons
+ \title Draggable Icons Example
+
+ The Draggable Icons example shows how to drag and drop image data between widgets
+ in the same application, and between different applications.
+
+ \image draggableicons-example.png
+
+ In many situations where drag and drop is used, the user starts dragging from
+ a particular widget and drops the payload onto another widget. In this example,
+ we subclass QLabel to create labels that we use as drag sources, and place them
+ inside \l{QWidget}s that serve as both containers and drop sites.
+
+ In addition, when a drag and drop operation occurs, we want to send more than
+ just an image. We also want to send information about where the user clicked in
+ the image so that the user can place it precisely on the drop target. This level
+ of detail means that we must create a custom MIME type for our data.
+
+ \section1 DragWidget Class Definition
+
+ The icon widgets that we use to display icons are subclassed from QLabel:
+
+ \snippet examples/draganddrop/draggableicons/dragwidget.h 0
+
+ Since the QLabel class provides most of what we require for the icon, we
+ only need to reimplement the \l QWidget::mousePressEvent() to provide
+ drag and drop facilities.
+
+ \section1 DragWidget Class Implementation
+
+ The \c DragWidget constructor sets an attribute on the widget that ensures
+ that it will be deleted when it is closed:
+
+ \snippet examples/draganddrop/draggableicons/dragwidget.cpp 0
+
+ To enable dragging from the icon, we need to act on a mouse press event.
+ We do this by reimplementing \l QWidget::mousePressEvent() and setting up
+ a QDrag object.
+
+ \snippet examples/draganddrop/draggableicons/dragwidget.cpp 1
+
+ Since we will be sending pixmap data for the icon and information about the
+ user's click in the icon widget, we construct a QByteArray and package up the
+ details using a QDataStream.
+
+ For interoperability, drag and drop operations describe the data they contain
+ using MIME types. In Qt, we describe this data using a QMimeData object:
+
+ \snippet examples/draganddrop/draggableicons/dragwidget.cpp 2
+
+ We choose an unofficial MIME type for this purpose, and supply the QByteArray
+ to the MIME data object.
+
+ The drag and drop operation itself is handled by a QDrag object:
+
+ \snippet examples/draganddrop/draggableicons/dragwidget.cpp 3
+
+ Here, we pass the data to the drag object, set a pixmap that will be shown
+ alongside the cursor during the operation, and define the position of a hot
+ spot that places the position of this pixmap under the cursor.
+
+*/