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++ // Copyright (C) 2016 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ #include <QtGui>
++ #include <QLabel>
++ #include <QHBoxLayout>
++ #include <QApplication>
++
++ #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);
++ }