qt5base-lts/examples/widgets/itemviews/puzzle/piecesmodel.cpp

/****************************************************************************
**
** Copyright (C) 2016 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the examples of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:BSD$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** BSD License Usage
** Alternatively, you may use this file under the terms of the BSD license
** as follows:
**
** "Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are
** met:
**   * Redistributions of source code must retain the above copyright
**     notice, this list of conditions and the following disclaimer.
**   * Redistributions in binary form must reproduce the above copyright
**     notice, this list of conditions and the following disclaimer in
**     the documentation and/or other materials provided with the
**     distribution.
**   * Neither the name of The Qt Company Ltd nor the names of its
**     contributors may be used to endorse or promote products derived
**     from this software without specific prior written permission.
**
**
** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "piecesmodel.h"

#include <QIcon>
#include <QMimeData>

PiecesModel::PiecesModel(int pieceSize, QObject *parent)
    : QAbstractListModel(parent), m_PieceSize(pieceSize)
{
}

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(m_PieceSize, m_PieceSize,
                         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 * qrand() / (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 (QAbstractListModel::flags(index)|Qt::ItemIsDragEnabled);

    return 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 = qvariant_cast<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()) {
        if (row < 0)
            endRow = pixmaps.size();
        else
            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;
}

void PiecesModel::addPieces(const QPixmap& pixmap)
{
    beginRemoveRows(QModelIndex(), 0, 24);
    pixmaps.clear();
    locations.clear();
    endRemoveRows();
    for (int y = 0; y < 5; ++y) {
        for (int x = 0; x < 5; ++x) {
            QPixmap pieceImage = pixmap.copy(x*m_PieceSize, y*m_PieceSize, m_PieceSize, m_PieceSize);
            addPiece(pieceImage, QPoint(x, y));
        }
    }
}