1 /**************************************************************************** 2 ** 3 ** Copyright (C) 2016 The Qt Company Ltd. 4 ** Contact: https://www.qt.io/licensing/ 5 ** 6 ** This file is part of the documentation of the Qt Toolkit. 7 ** 8 ** $QT_BEGIN_LICENSE:BSD$ 9 ** Commercial License Usage 10 ** Licensees holding valid commercial Qt licenses may use this file in 11 ** accordance with the commercial license agreement provided with the 12 ** Software or, alternatively, in accordance with the terms contained in 13 ** a written agreement between you and The Qt Company. For licensing terms 14 ** and conditions see https://www.qt.io/terms-conditions. For further 15 ** information use the contact form at https://www.qt.io/contact-us. 16 ** 17 ** BSD License Usage 18 ** Alternatively, you may use this file under the terms of the BSD license 19 ** as follows: 20 ** 21 ** "Redistribution and use in source and binary forms, with or without 22 ** modification, are permitted provided that the following conditions are 23 ** met: 24 ** * Redistributions of source code must retain the above copyright 25 ** notice, this list of conditions and the following disclaimer. 26 ** * Redistributions in binary form must reproduce the above copyright 27 ** notice, this list of conditions and the following disclaimer in 28 ** the documentation and/or other materials provided with the 29 ** distribution. 30 ** * Neither the name of The Qt Company Ltd nor the names of its 31 ** contributors may be used to endorse or promote products derived 32 ** from this software without specific prior written permission. 33 ** 34 ** 35 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 36 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 37 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 38 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 39 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 40 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 41 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 42 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 43 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 44 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 45 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE." 46 ** 47 ** $QT_END_LICENSE$ 48 ** 49 ****************************************************************************/ 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