/****************************************************************************
**
** Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Qt Software Information (qt-info@nokia.com)
**
** This file is part of the example classes of the Qt Toolkit.
**
** Commercial Usage
** Licensees holding valid Qt Commercial licenses may use this file in
** accordance with the Qt Commercial License Agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Nokia.
**
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License versions 2.0 or 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 GNU General Public Licensing requirements will be met:
** http://www.fsf.org/licensing/licenses/info/GPLv2.html and
** http://www.gnu.org/copyleft/gpl.html.  In addition, as a special
** exception, Nokia gives you certain additional rights. These rights
** are described in the Nokia Qt GPL Exception version 1.3, included in
** the file GPL_EXCEPTION.txt in this package.
**
** Qt for Windows(R) Licensees
** As a special exception, Nokia, as the sole copyright holder for Qt
** Designer, grants users of the Qt/Eclipse Integration plug-in the
** right for the Qt/Eclipse Integration to link to functionality
** provided by Qt Designer and its related libraries.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at qt-sales@nokia.com.
**
****************************************************************************/

#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 stream(&pieceData, QIODevice::ReadOnly);
        QRect square = targetSquare(event->pos());
        QPixmap pixmap;
        QPoint location;
        stream >> 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->start(Qt::MoveAction) == 0) {
        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);
}
