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50
51#include <QtWidgets>
52#include <QtSvg>
53#include "mimedata.h"
54#include "sourcewidget.h"
55
56SourceWidget::SourceWidget(QWidget *parent)
57 : QWidget(parent)
58{
59 QFile imageFile(":/images/example.svg");
60 imageFile.open(flags: QIODevice::ReadOnly);
61 imageData = imageFile.readAll();
62 imageFile.close();
63
64 QScrollArea *imageArea = new QScrollArea;
65 imageLabel = new QSvgWidget;
66 imageLabel->renderer()->load(contents: imageData);
67 imageArea->setWidget(imageLabel);
68 //imageLabel->setMinimumSize(imageLabel->renderer()->viewBox().size());
69
70 QLabel *instructTopLabel = new QLabel(tr(s: "This is an SVG drawing:"));
71 QLabel *instructBottomLabel = new QLabel(
72 tr(s: "Drag the icon to copy the drawing as a PNG file:"));
73 instructBottomLabel->setWordWrap(true);
74 QPushButton *dragIcon = new QPushButton(tr(s: "Export"));
75 dragIcon->setIcon(QIcon(":/images/drag.png"));
76
77 connect(sender: dragIcon, SIGNAL(pressed()), receiver: this, SLOT(startDrag()));
78
79 QGridLayout *layout = new QGridLayout;
80 layout->addWidget(instructTopLabel, row: 0, column: 0, rowSpan: 1, columnSpan: 2);
81 layout->addWidget(imageArea, row: 1, column: 0, rowSpan: 2, columnSpan: 2);
82 layout->addWidget(instructBottomLabel, row: 3, column: 0);
83 layout->addWidget(dragIcon, row: 3, column: 1);
84 setLayout(layout);
85 setWindowTitle(tr(s: "Delayed Encoding"));
86}
87
88//![1]
89void SourceWidget::createData(const QString &mimeType)
90{
91 if (mimeType != "image/png")
92 return;
93
94 QImage image(imageLabel->size(), QImage::Format_RGB32);
95 QPainter painter;
96 painter.begin(&image);
97 imageLabel->renderer()->render(p: &painter);
98 painter.end();
99
100 QByteArray data;
101 QBuffer buffer(&data);
102 buffer.open(openMode: QIODevice::WriteOnly);
103 image.save(device: &buffer, format: "PNG");
104 buffer.close();
105
106 mimeData->setData(mimetype: "image/png", data);
107}
108//![1]
109
110//![0]
111void SourceWidget::startDrag()
112{
113 mimeData = new MimeData;
114
115 connect(sender: mimeData, SIGNAL(dataRequested(QString)),
116 receiver: this, SLOT(createData(QString)), Qt::DirectConnection);
117
118 QDrag *drag = new QDrag(this);
119 drag->setMimeData(mimeData);
120 drag->setPixmap(QPixmap(":/images/drag.png"));
121
122 drag->exec(supportedActions: Qt::CopyAction);
123}
124//![0]
125
126

source code of qtsvg/examples/svg/draganddrop/delayedencoding/sourcewidget.cpp