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#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);

}