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/****************************************************************************
**
** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the documentation 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 either Technology Preview License Agreement or the
** Beta Release License Agreement.
**
** 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 1.0, included in the file LGPL_EXCEPTION.txt in this
** package.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 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 the GNU General Public License version 3.0 requirements will be
** met: http://www.gnu.org/copyleft/gpl.html.
**
** If you are unsure which license is appropriate for your use, please
** contact the sales department at http://qt.nokia.com/contact.
** $QT_END_LICENSE$
**
****************************************************************************/

#include <QtGui>

#include "dragwidget.h"

DragWidget::DragWidget(QWidget *parent)
    : QFrame(parent)
{
    setFrameStyle(QFrame::StyledPanel | QFrame::Sunken);
    dragDropLabel = new QLabel("", this);
    dragDropLabel->setAlignment(Qt::AlignHCenter);

    QHBoxLayout *layout = new QHBoxLayout(this);
    layout->addStretch(0);
    layout->addWidget(dragDropLabel);
    layout->addStretch(0);

    setAcceptDrops(true);
}

// Accept all actions, but deal with them separately later.
//! [0]
void DragWidget::dragEnterEvent(QDragEnterEvent *event)
{
    event->acceptProposedAction();
}
//! [0]

//! [1]
void DragWidget::dropEvent(QDropEvent *event)
{
    if (event->source() == this && event->possibleActions() & Qt::MoveAction)
        return;
//! [1]

//! [2]
    if (event->proposedAction() == Qt::MoveAction) {
        event->acceptProposedAction();
        // Process the data from the event.
//! [2]
        emit dragResult(tr("The data was moved here."));
//! [3]
    } else if (event->proposedAction() == Qt::CopyAction) {
        event->acceptProposedAction();
        // Process the data from the event.
//! [3]
        emit dragResult(tr("The data was copied here."));
//! [4]
    } else {
        // Ignore the drop.
        return;
    }
//! [4]
    // End of quote

    emit mimeTypes(event->mimeData()->formats());
    setData(event->mimeData()->formats()[0],
            event->mimeData()->data(event->mimeData()->formats()[0]));
//! [5]
}
//! [5]

//! [6]
void DragWidget::mousePressEvent(QMouseEvent *event)
{
    if (event->button() == Qt::LeftButton)
        dragStartPosition = event->pos();
}
//! [6]

//! [7]
void DragWidget::mouseMoveEvent(QMouseEvent *event)
{
    if (!(event->buttons() & Qt::LeftButton))
        return;
    if ((event->pos() - dragStartPosition).manhattanLength()
         < QApplication::startDragDistance())
        return;

    QDrag *drag = new QDrag(this);
    QMimeData *mimeData = new QMimeData;

    mimeData->setData(mimeType, data);
    drag->setMimeData(mimeData);

    Qt::DropAction dropAction = drag->exec(Qt::CopyAction | Qt::MoveAction);
//! [7]

    switch (dropAction) {
        case Qt::CopyAction:
            emit dragResult(tr("The text was copied."));
            break;
        case Qt::MoveAction:
            emit dragResult(tr("The text was moved."));
            break;
        default:
            emit dragResult(tr("Unknown action."));
            break;
    }
//! [8]
}
//! [8]

void DragWidget::setData(const QString &mimetype, const QByteArray &newData)
{
    mimeType = mimetype;
    data = QByteArray(newData);

    dragDropLabel->setText(tr("%1 bytes").arg(data.size()));

    QStringList formats;
    formats << mimetype;
    emit mimeTypes(formats);
}