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50 
51 /*
52 finalwidget.cpp
53 
54 A widget to display an image and a label containing a description.
55 */
56 
57 #include <QtGui>
58 #include "finalwidget.h"
59 
FinalWidget(QWidget * parent,const QString & name,const QSize & labelSize)60 FinalWidget::FinalWidget(QWidget *parent, const QString &name,
61                          const QSize &labelSize)
62     : QFrame(parent)
63 {
64     hasImage = false;
65     imageLabel = new QLabel;
66     imageLabel->setFrameShadow(QFrame::Sunken);
67     imageLabel->setFrameShape(QFrame::StyledPanel);
68     imageLabel->setMinimumSize(labelSize);
69     nameLabel = new QLabel(name);
70 
71     QVBoxLayout *layout = new QVBoxLayout;
72     layout->addWidget(imageLabel, 1);
73     layout->addWidget(nameLabel, 0);
74     setLayout(layout);
75 }
76 
77 /*!
78     If the mouse moves far enough when the left mouse button is held down,
79     start a drag and drop operation.
80 */
81 
mouseMoveEvent(QMouseEvent * event)82 void FinalWidget::mouseMoveEvent(QMouseEvent *event)
83 {
84     if (!(event->buttons() & Qt::LeftButton))
85         return;
86     if ((event->pos() - dragStartPosition).manhattanLength()
87          < QApplication::startDragDistance())
88         return;
89     if (!hasImage)
90         return;
91 
92     QDrag *drag = new QDrag(this);
93     QMimeData *mimeData = new QMimeData;
94 
95 //! [0]
96     QByteArray output;
97     QBuffer outputBuffer(&output);
98     outputBuffer.open(QIODevice::WriteOnly);
99     imageLabel->pixmap()->toImage().save(&outputBuffer, "PNG");
100     mimeData->setData("image/png", output);
101 //! [0]
102 /*
103 //! [1]
104     mimeData->setImageData(QVariant(*imageLabel->pixmap()));
105 //! [1]
106 */
107     drag->setMimeData(mimeData);
108     drag->setPixmap(imageLabel->pixmap()->scaled(64, 64, Qt::KeepAspectRatio));
109 //! [2]
110     drag->setHotSpot(QPoint(drag->pixmap().width()/2,
111                             drag->pixmap().height()));
112 //! [2]
113 
114     drag->start();
115 }
116 
117 /*!
118     Check for left mouse button presses in order to enable drag and drop.
119 */
120 
mousePressEvent(QMouseEvent * event)121 void FinalWidget::mousePressEvent(QMouseEvent *event)
122 {
123     if (event->button() == Qt::LeftButton)
124         dragStartPosition = event->pos();
125 }
126 
pixmap() const127 const QPixmap* FinalWidget::pixmap() const
128 {
129     return imageLabel->pixmap();
130 }
131 
setPixmap(const QPixmap & pixmap)132 void FinalWidget::setPixmap(const QPixmap &pixmap)
133 {
134     imageLabel->setPixmap(pixmap);
135     hasImage = true;
136 }
137