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50 
51 //! [0]
52 QGraphicsScene scene;
53 scene.addText("Hello, world!");
54 
55 QGraphicsView view(&scene);
56 view.show();
57 //! [0]
58 
59 
60 //! [1]
61 QGraphicsScene scene;
62 scene.addItem(...
63 ...
64 QPrinter printer(QPrinter::HighResolution);
65 printer.setPaperSize(QPrinter::A4);
66 
67 QPainter painter(&printer);
68 scene.render(&painter);
69 //! [1]
70 
71 
72 //! [2]
73 QSizeF segmentSize = sceneRect().size() / pow(2, depth - 1);
74 //! [2]
75 
76 
77 //! [3]
78 QGraphicsScene scene;
79 QGraphicsView view(&scene);
80 view.show();
81 
82 // a blue background
83 scene.setBackgroundBrush(Qt::blue);
84 
85 // a gradient background
86 QRadialGradient gradient(0, 0, 10);
87 gradient.setSpread(QGradient::RepeatSpread);
88 scene.setBackgroundBrush(gradient);
89 //! [3]
90 
91 
92 //! [4]
93 QGraphicsScene scene;
94 QGraphicsView view(&scene);
95 view.show();
96 
97 // a white semi-transparent foreground
98 scene.setForegroundBrush(QColor(255, 255, 255, 127));
99 
100 // a grid foreground
101 scene.setForegroundBrush(QBrush(Qt::lightGray, Qt::CrossPattern));
102 //! [4]
103 
104 
105 //! [5]
106 QRectF TileScene::rectForTile(int x, int y) const
107 {
108     // Return the rectangle for the tile at position (x, y).
109     return QRectF(x * tileWidth, y * tileHeight, tileWidth, tileHeight);
110 }
111 
112 void TileScene::setTile(int x, int y, const QPixmap &pixmap)
113 {
114     // Sets or replaces the tile at position (x, y) with pixmap.
115     if (x >= 0 && x < numTilesH && y >= 0 && y < numTilesV) {
116         tiles[y][x] = pixmap;
117         invalidate(rectForTile(x, y), BackgroundLayer);
118     }
119 }
120 
121 void TileScene::drawBackground(QPainter *painter, const QRectF &exposed)
122 {
123     // Draws all tiles that intersect the exposed area.
124     for (int y = 0; y < numTilesV; ++y) {
125         for (int x = 0; x < numTilesH; ++x) {
126             QRectF rect = rectForTile(x, y);
127             if (exposed.intersects(rect))
128                 painter->drawPixmap(rect.topLeft(), tiles[y][x]);
129         }
130     }
131 }
132 //! [5]
133