Revision control
++ // Copyright (C) 2016 The Qt Company Ltd.
++ // SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
++
++ /*
++ finalwidget.cpp
++
++ A widget to display an image and a label containing a description.
++ */
++
++ #include "finalwidget.h"
++
++ #include <QApplication>
++ #include <QBuffer>
++ #include <QDrag>
++ #include <QLabel>
++ #include <QMimeData>
++ #include <QMouseEvent>
++ #include <QVBoxLayout>
++
++ FinalWidget::FinalWidget(QWidget *parent, const QString &name,
++ const QSize &labelSize)
++ : QFrame(parent)
++ {
++ hasImage = false;
++ imageLabel = new QLabel;
++ imageLabel->setFrameShadow(QFrame::Sunken);
++ imageLabel->setFrameShape(QFrame::StyledPanel);
++ imageLabel->setMinimumSize(labelSize);
++ nameLabel = new QLabel(name);
++
++ QVBoxLayout *layout = new QVBoxLayout(this);
++ layout->addWidget(imageLabel, 1);
++ layout->addWidget(nameLabel, 0);
++ }
++
++ /*!
++ If the mouse moves far enough when the left mouse button is held down,
++ start a drag and drop operation.
++ */
++
++ void FinalWidget::mouseMoveEvent(QMouseEvent *event)
++ {
++ if (!(event->buttons() & Qt::LeftButton))
++ return;
++ if ((event->pos() - dragStartPosition).manhattanLength()
++ < QApplication::startDragDistance())
++ return;
++ if (!hasImage)
++ return;
++
++ QDrag *drag = new QDrag(this);
++ QMimeData *mimeData = new QMimeData;
++
++ //! [0]
++ QByteArray output;
++ QBuffer outputBuffer(&output);
++ outputBuffer.open(QIODevice::WriteOnly);
++ imageLabel->pixmap().toImage().save(&outputBuffer, "PNG");
++ mimeData->setData("image/png", output);
++ //! [0]
++ /*
++ //! [1]
++ mimeData->setImageData(QVariant(*imageLabel->pixmap()));
++ //! [1]
++ */
++ drag->setMimeData(mimeData);
++ drag->setPixmap(imageLabel->pixmap().scaled(64, 64, Qt::KeepAspectRatio));
++ //! [2]
++ drag->setHotSpot(QPoint(drag->pixmap().width()/2,
++ drag->pixmap().height()));
++ //! [2]
++ }
++
++ /*!
++ Check for left mouse button presses in order to enable drag and drop.
++ */
++
++ void FinalWidget::mousePressEvent(QMouseEvent *event)
++ {
++ if (event->button() == Qt::LeftButton)
++ dragStartPosition = event->pos();
++ }
++
++ QPixmap FinalWidget::pixmap() const
++ {
++ return imageLabel->pixmap();
++ }
++
++ void FinalWidget::setPixmap(const QPixmap &pixmap)
++ {
++ imageLabel->setPixmap(pixmap);
++ hasImage = true;
++ }