--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/draganddrop/puzzle/puzzlewidget.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,205 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples 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 Technology Preview License Agreement accompanying
+** this package.
+**
+** 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 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtGui>
+
+#include "puzzlewidget.h"
+
+PuzzleWidget::PuzzleWidget(QWidget *parent)
+    : QWidget(parent)
+{
+    setAcceptDrops(true);
+    setMinimumSize(400, 400);
+    setMaximumSize(400, 400);
+}
+
+void PuzzleWidget::clear()
+{
+    pieceLocations.clear();
+    piecePixmaps.clear();
+    pieceRects.clear();
+    highlightedRect = QRect();
+    inPlace = 0;
+    update();
+}
+
+void PuzzleWidget::dragEnterEvent(QDragEnterEvent *event)
+{
+    if (event->mimeData()->hasFormat("image/x-puzzle-piece"))
+        event->accept();
+    else
+        event->ignore();
+}
+
+void PuzzleWidget::dragLeaveEvent(QDragLeaveEvent *event)
+{
+    QRect updateRect = highlightedRect;
+    highlightedRect = QRect();
+    update(updateRect);
+    event->accept();
+}
+
+void PuzzleWidget::dragMoveEvent(QDragMoveEvent *event)
+{
+    QRect updateRect = highlightedRect.unite(targetSquare(event->pos()));
+
+    if (event->mimeData()->hasFormat("image/x-puzzle-piece")
+        && findPiece(targetSquare(event->pos())) == -1) {
+
+        highlightedRect = targetSquare(event->pos());
+        event->setDropAction(Qt::MoveAction);
+        event->accept();
+    } else {
+        highlightedRect = QRect();
+        event->ignore();
+    }
+
+    update(updateRect);
+}
+
+void PuzzleWidget::dropEvent(QDropEvent *event)
+{
+    if (event->mimeData()->hasFormat("image/x-puzzle-piece")
+        && findPiece(targetSquare(event->pos())) == -1) {
+
+        QByteArray pieceData = event->mimeData()->data("image/x-puzzle-piece");
+        QDataStream dataStream(&pieceData, QIODevice::ReadOnly);
+        QRect square = targetSquare(event->pos());
+        QPixmap pixmap;
+        QPoint location;
+        dataStream >> pixmap >> location;
+
+        pieceLocations.append(location);
+        piecePixmaps.append(pixmap);
+        pieceRects.append(square);
+
+        highlightedRect = QRect();
+        update(square);
+
+        event->setDropAction(Qt::MoveAction);
+        event->accept();
+
+        if (location == QPoint(square.x()/80, square.y()/80)) {
+            inPlace++;
+            if (inPlace == 25)
+                emit puzzleCompleted();
+        }
+    } else {
+        highlightedRect = QRect();
+        event->ignore();
+    }
+}
+
+int PuzzleWidget::findPiece(const QRect &pieceRect) const
+{
+    for (int i = 0; i < pieceRects.size(); ++i) {
+        if (pieceRect == pieceRects[i]) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+void PuzzleWidget::mousePressEvent(QMouseEvent *event)
+{
+    QRect square = targetSquare(event->pos());
+    int found = findPiece(square);
+
+    if (found == -1)
+        return;
+
+    QPoint location = pieceLocations[found];
+    QPixmap pixmap = piecePixmaps[found];
+    pieceLocations.removeAt(found);
+    piecePixmaps.removeAt(found);
+    pieceRects.removeAt(found);
+
+    if (location == QPoint(square.x()/80, square.y()/80))
+        inPlace--;
+
+    update(square);
+
+    QByteArray itemData;
+    QDataStream dataStream(&itemData, QIODevice::WriteOnly);
+
+    dataStream << pixmap << location;
+
+    QMimeData *mimeData = new QMimeData;
+    mimeData->setData("image/x-puzzle-piece", itemData);
+
+    QDrag *drag = new QDrag(this);
+    drag->setMimeData(mimeData);
+    drag->setHotSpot(event->pos() - square.topLeft());
+    drag->setPixmap(pixmap);
+
+    if (!(drag->exec(Qt::MoveAction) == Qt::MoveAction)) {
+        pieceLocations.insert(found, location);
+        piecePixmaps.insert(found, pixmap);
+        pieceRects.insert(found, square);
+        update(targetSquare(event->pos()));
+
+        if (location == QPoint(square.x()/80, square.y()/80))
+            inPlace++;
+    }
+}
+
+void PuzzleWidget::paintEvent(QPaintEvent *event)
+{
+    QPainter painter;
+    painter.begin(this);
+    painter.fillRect(event->rect(), Qt::white);
+
+    if (highlightedRect.isValid()) {
+        painter.setBrush(QColor("#ffcccc"));
+        painter.setPen(Qt::NoPen);
+        painter.drawRect(highlightedRect.adjusted(0, 0, -1, -1));
+    }
+
+    for (int i = 0; i < pieceRects.size(); ++i) {
+        painter.drawPixmap(pieceRects[i], piecePixmaps[i]);
+    }
+    painter.end();
+}
+
+const QRect PuzzleWidget::targetSquare(const QPoint &position) const
+{
+    return QRect(position.x()/80 * 80, position.y()/80 * 80, 80, 80);
+}