/******************************************************************************** Copyright (C) 2005-2006 Trolltech ASA. All rights reserved.**** This file is part of the example classes of the Qt Toolkit.**** This file may be used under the terms of the GNU General Public** License version 2.0 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 GNU** General Public Licensing requirements will be met:** http://www.trolltech.com/products/qt/opensource.html**** If you are unsure which license is appropriate for your use, please** review the following information:** http://www.trolltech.com/products/qt/licensing.html or contact the** sales department at sales@trolltech.com.**** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.******************************************************************************/#include <QtGui>#include "piecesmodel.h"PiecesModel::PiecesModel(QObject *parent)    : QAbstractListModel(parent){}QVariant PiecesModel::data(const QModelIndex &index, int role) const{    if (!index.isValid())        return QVariant();    if (role == Qt::DecorationRole)        return QIcon(pixmaps.value(index.row()).scaled(60, 60,                         Qt::KeepAspectRatio, Qt::SmoothTransformation));    else if (role == Qt::UserRole)        return pixmaps.value(index.row());    else if (role == Qt::UserRole + 1)        return locations.value(index.row());    return QVariant();}void PiecesModel::addPiece(const QPixmap &pixmap, const QPoint &location){    int row;    if (int(2.0*rand()/(RAND_MAX+1.0)) == 1)        row = 0;    else        row = pixmaps.size();    beginInsertRows(QModelIndex(), row, row);    pixmaps.insert(row, pixmap);    locations.insert(row, location);    endInsertRows();}Qt::ItemFlags PiecesModel::flags(const QModelIndex &index) const{    if (index.isValid()) {        return (Qt::ItemIsEnabled | Qt::ItemIsSelectable              | Qt::ItemIsDragEnabled | Qt::ItemIsSelectable | Qt::ItemIsDropEnabled);    }    return Qt::ItemIsEnabled | Qt::ItemIsDropEnabled;}bool PiecesModel::removeRows(int row, int count, const QModelIndex &parent){    if (parent.isValid())        return false;    if (row >= pixmaps.size() || row + count <= 0)        return false;    int beginRow = qMax(0, row);    int endRow = qMin(row + count - 1, pixmaps.size() - 1);    beginRemoveRows(parent, beginRow, endRow);    while (beginRow <= endRow) {        pixmaps.removeAt(beginRow);        locations.removeAt(beginRow);        ++beginRow;    }    endRemoveRows();    return true;}QStringList PiecesModel::mimeTypes() const{    QStringList types;    types << "image/x-puzzle-piece";    return types;}QMimeData *PiecesModel::mimeData(const QModelIndexList &indexes) const{    QMimeData *mimeData = new QMimeData();    QByteArray encodedData;    QDataStream stream(&encodedData, QIODevice::WriteOnly);    foreach (QModelIndex index, indexes) {        if (index.isValid()) {            QPixmap pixmap = qVariantValue<QPixmap>(data(index, Qt::UserRole));            QPoint location = data(index, Qt::UserRole+1).toPoint();            stream << pixmap << location;        }    }    mimeData->setData("image/x-puzzle-piece", encodedData);    return mimeData;}bool PiecesModel::dropMimeData(const QMimeData *data, Qt::DropAction action,                               int row, int column, const QModelIndex &parent){    if (!data->hasFormat("image/x-puzzle-piece"))        return false;    if (action == Qt::IgnoreAction)        return true;    if (column > 0)        return false;    int endRow;    if (!parent.isValid() && row < 0)        endRow = pixmaps.size();    else if (!parent.isValid())        endRow = qMin(row, pixmaps.size());    else        endRow = parent.row();    QByteArray encodedData = data->data("image/x-puzzle-piece");    QDataStream stream(&encodedData, QIODevice::ReadOnly);    while (!stream.atEnd()) {        QPixmap pixmap;        QPoint location;        stream >> pixmap >> location;        beginInsertRows(QModelIndex(), endRow, endRow);        pixmaps.insert(endRow, pixmap);        locations.insert(endRow, location);        endInsertRows();        ++endRow;    }    return true;}int PiecesModel::rowCount(const QModelIndex &parent) const{    if (parent.isValid())        return 0;    else        return pixmaps.size();}Qt::DropActions PiecesModel::supportedDropActions() const{    return Qt::CopyAction | Qt::MoveAction;}