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50#include <QStandardItem>
51#include <QtCore/qmimedata.h>
52#include <QtGui/qdrag.h>
53#include <QtPrintSupport/qprintdialog.h>
54#include <QtPrintSupport/qprinter.h>
55#include <QtWidgets/QGraphicsSceneMouseEvent>
56#include <QtWidgets/qdialog.h>
57#include <QtWidgets/qgraphicsview.h>
58#include <QtWidgets/qopenglwidget.h>
59
60void graphicsview_snippet_main()
61{
62//! [0]
63QGraphicsScene scene;
64QGraphicsRectItem *rect = scene.addRect(rect: QRectF(0, 0, 100, 100));
65
66QGraphicsItem *item = scene.itemAt(x: 50, y: 50, deviceTransform: QTransform());
67//! [0]
68Q_UNUSED(rect);
69Q_UNUSED(item);
70}
71
72void myPopulateScene(QGraphicsScene *)
73{
74 // Intentionally left empty
75}
76
77void snippetThatUsesMyPopulateScene()
78{
79//! [1]
80QGraphicsScene scene;
81myPopulateScene(&scene);
82QGraphicsView view(&scene);
83view.show();
84//! [1]
85}
86
87class CustomItem : public QStandardItem
88{
89public:
90 using QStandardItem::QStandardItem;
91
92 int type() const override { return UserType; }
93 void mousePressEvent(QGraphicsSceneMouseEvent *event);
94 QStandardItem *clone() const override { return new CustomItem; }
95};
96
97
98void printScene()
99{
100//! [3]
101QGraphicsScene scene;
102QPrinter printer;
103scene.addRect(rect: QRectF(0, 0, 100, 200), pen: QPen(Qt::black), brush: QBrush(Qt::green));
104
105if (QPrintDialog(&printer).exec() == QDialog::Accepted) {
106 QPainter painter(&printer);
107 painter.setRenderHint(hint: QPainter::Antialiasing);
108 scene.render(painter: &painter);
109}
110//! [3]
111}
112
113void pixmapScene()
114{
115//! [4]
116QGraphicsScene scene;
117scene.addRect(rect: QRectF(0, 0, 100, 200), pen: QPen(Qt::black), brush: QBrush(Qt::green));
118
119QPixmap pixmap;
120QPainter painter(&pixmap);
121painter.setRenderHint(hint: QPainter::Antialiasing);
122scene.render(painter: &painter);
123painter.end();
124
125pixmap.save(fileName: "scene.png");
126//! [4]
127}
128
129//! [5]
130void CustomItem::mousePressEvent(QGraphicsSceneMouseEvent *event)
131{
132 QMimeData *data = new QMimeData;
133 QDrag *drag = new QDrag(event->widget());
134 drag->setMimeData(data);
135 drag->exec();
136}
137//! [5]
138
139void viewScene()
140{
141QGraphicsScene scene;
142//! [6]
143QGraphicsView view(&scene);
144QOpenGLWidget *gl = new QOpenGLWidget();
145QSurfaceFormat format;
146format.setSamples(4);
147gl->setFormat(format);
148view.setViewport(gl);
149//! [6]
150}
151

source code of qtbase/src/widgets/doc/snippets/graphicsview/graphicsview.cpp