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1 /**************************************************************************** |
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2 ** |
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3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). |
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4 ** All rights reserved. |
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5 ** Contact: Nokia Corporation (qt-info@nokia.com) |
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6 ** |
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7 ** This file is part of the examples of the Qt Toolkit. |
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8 ** |
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9 ** $QT_BEGIN_LICENSE:LGPL$ |
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10 ** No Commercial Usage |
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11 ** This file contains pre-release code and may not be distributed. |
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12 ** You may use this file in accordance with the terms and conditions |
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13 ** contained in the Technology Preview License Agreement accompanying |
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14 ** this package. |
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15 ** |
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16 ** GNU Lesser General Public License Usage |
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17 ** Alternatively, this file may be used under the terms of the GNU Lesser |
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18 ** General Public License version 2.1 as published by the Free Software |
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19 ** Foundation and appearing in the file LICENSE.LGPL included in the |
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20 ** packaging of this file. Please review the following information to |
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21 ** ensure the GNU Lesser General Public License version 2.1 requirements |
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22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html. |
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23 ** |
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24 ** In addition, as a special exception, Nokia gives you certain additional |
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25 ** rights. These rights are described in the Nokia Qt LGPL Exception |
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26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package. |
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27 ** |
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28 ** If you have questions regarding the use of this file, please contact |
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29 ** Nokia at qt-info@nokia.com. |
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30 ** |
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31 ** |
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32 ** |
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33 ** |
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34 ** |
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35 ** |
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36 ** |
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37 ** |
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38 ** $QT_END_LICENSE$ |
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39 ** |
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40 ****************************************************************************/ |
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41 |
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42 #include "graphwidget.h" |
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43 #include "edge.h" |
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44 #include "node.h" |
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45 |
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46 #include <QDebug> |
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47 #include <QGraphicsScene> |
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48 #include <QWheelEvent> |
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49 |
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50 #include <math.h> |
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51 |
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52 GraphWidget::GraphWidget() |
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53 : timerId(0) |
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54 { |
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55 QGraphicsScene *scene = new QGraphicsScene(this); |
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56 scene->setItemIndexMethod(QGraphicsScene::NoIndex); |
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57 scene->setSceneRect(-200, -200, 400, 400); |
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58 setScene(scene); |
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59 setCacheMode(CacheBackground); |
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60 setViewportUpdateMode(BoundingRectViewportUpdate); |
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61 setRenderHint(QPainter::Antialiasing); |
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62 setTransformationAnchor(AnchorUnderMouse); |
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63 setResizeAnchor(AnchorViewCenter); |
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64 |
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65 Node *node1 = new Node(this); |
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66 Node *node2 = new Node(this); |
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67 Node *node3 = new Node(this); |
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68 Node *node4 = new Node(this); |
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69 centerNode = new Node(this); |
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70 Node *node6 = new Node(this); |
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71 Node *node7 = new Node(this); |
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72 Node *node8 = new Node(this); |
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73 Node *node9 = new Node(this); |
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74 scene->addItem(node1); |
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75 scene->addItem(node2); |
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76 scene->addItem(node3); |
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77 scene->addItem(node4); |
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78 scene->addItem(centerNode); |
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79 scene->addItem(node6); |
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80 scene->addItem(node7); |
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81 scene->addItem(node8); |
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82 scene->addItem(node9); |
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83 scene->addItem(new Edge(node1, node2)); |
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84 scene->addItem(new Edge(node2, node3)); |
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85 scene->addItem(new Edge(node2, centerNode)); |
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86 scene->addItem(new Edge(node3, node6)); |
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87 scene->addItem(new Edge(node4, node1)); |
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88 scene->addItem(new Edge(node4, centerNode)); |
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89 scene->addItem(new Edge(centerNode, node6)); |
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90 scene->addItem(new Edge(centerNode, node8)); |
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91 scene->addItem(new Edge(node6, node9)); |
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92 scene->addItem(new Edge(node7, node4)); |
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93 scene->addItem(new Edge(node8, node7)); |
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94 scene->addItem(new Edge(node9, node8)); |
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95 |
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96 node1->setPos(-50, -50); |
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97 node2->setPos(0, -50); |
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98 node3->setPos(50, -50); |
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99 node4->setPos(-50, 0); |
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100 centerNode->setPos(0, 0); |
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101 node6->setPos(50, 0); |
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102 node7->setPos(-50, 50); |
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103 node8->setPos(0, 50); |
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104 node9->setPos(50, 50); |
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105 |
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106 scale(qreal(0.8), qreal(0.8)); |
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107 setMinimumSize(400, 400); |
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108 setWindowTitle(tr("Elastic Nodes")); |
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109 } |
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110 |
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111 void GraphWidget::itemMoved() |
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112 { |
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113 if (!timerId) |
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114 timerId = startTimer(1000 / 25); |
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115 } |
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116 |
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117 void GraphWidget::keyPressEvent(QKeyEvent *event) |
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118 { |
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119 switch (event->key()) { |
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120 case Qt::Key_Up: |
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121 centerNode->moveBy(0, -20); |
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122 break; |
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123 case Qt::Key_Down: |
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124 centerNode->moveBy(0, 20); |
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125 break; |
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126 case Qt::Key_Left: |
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127 centerNode->moveBy(-20, 0); |
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128 break; |
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129 case Qt::Key_Right: |
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130 centerNode->moveBy(20, 0); |
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131 break; |
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132 case Qt::Key_Plus: |
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133 scaleView(qreal(1.2)); |
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134 break; |
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135 case Qt::Key_Minus: |
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136 scaleView(1 / qreal(1.2)); |
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137 break; |
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138 case Qt::Key_Space: |
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139 case Qt::Key_Enter: |
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140 foreach (QGraphicsItem *item, scene()->items()) { |
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141 if (qgraphicsitem_cast<Node *>(item)) |
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142 item->setPos(-150 + qrand() % 300, -150 + qrand() % 300); |
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143 } |
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144 break; |
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145 default: |
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146 QGraphicsView::keyPressEvent(event); |
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147 } |
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148 } |
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149 |
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150 void GraphWidget::timerEvent(QTimerEvent *event) |
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151 { |
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152 Q_UNUSED(event); |
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153 |
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154 QList<Node *> nodes; |
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155 foreach (QGraphicsItem *item, scene()->items()) { |
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156 if (Node *node = qgraphicsitem_cast<Node *>(item)) |
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157 nodes << node; |
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158 } |
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159 |
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160 foreach (Node *node, nodes) |
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161 node->calculateForces(); |
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162 |
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163 bool itemsMoved = false; |
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164 foreach (Node *node, nodes) { |
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165 if (node->advance()) |
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166 itemsMoved = true; |
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167 } |
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168 |
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169 if (!itemsMoved) { |
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170 killTimer(timerId); |
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171 timerId = 0; |
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172 } |
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173 } |
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174 |
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175 void GraphWidget::wheelEvent(QWheelEvent *event) |
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176 { |
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177 scaleView(pow((double)2, -event->delta() / 240.0)); |
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178 } |
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179 |
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180 void GraphWidget::drawBackground(QPainter *painter, const QRectF &rect) |
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181 { |
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182 Q_UNUSED(rect); |
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183 |
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184 // Shadow |
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185 QRectF sceneRect = this->sceneRect(); |
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186 QRectF rightShadow(sceneRect.right(), sceneRect.top() + 5, 5, sceneRect.height()); |
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187 QRectF bottomShadow(sceneRect.left() + 5, sceneRect.bottom(), sceneRect.width(), 5); |
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188 if (rightShadow.intersects(rect) || rightShadow.contains(rect)) |
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189 painter->fillRect(rightShadow, Qt::darkGray); |
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190 if (bottomShadow.intersects(rect) || bottomShadow.contains(rect)) |
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191 painter->fillRect(bottomShadow, Qt::darkGray); |
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192 |
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193 // Fill |
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194 QLinearGradient gradient(sceneRect.topLeft(), sceneRect.bottomRight()); |
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195 gradient.setColorAt(0, Qt::white); |
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196 gradient.setColorAt(1, Qt::lightGray); |
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197 painter->fillRect(rect.intersect(sceneRect), gradient); |
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198 painter->setBrush(Qt::NoBrush); |
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199 painter->drawRect(sceneRect); |
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200 |
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201 // Text |
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202 QRectF textRect(sceneRect.left() + 4, sceneRect.top() + 4, |
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203 sceneRect.width() - 4, sceneRect.height() - 4); |
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204 QString message(tr("Click and drag the nodes around, and zoom with the mouse " |
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205 "wheel or the '+' and '-' keys")); |
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206 |
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207 QFont font = painter->font(); |
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208 font.setBold(true); |
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209 font.setPointSize(14); |
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210 painter->setFont(font); |
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211 painter->setPen(Qt::lightGray); |
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212 painter->drawText(textRect.translated(2, 2), message); |
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213 painter->setPen(Qt::black); |
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214 painter->drawText(textRect, message); |
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215 } |
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216 |
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217 void GraphWidget::scaleView(qreal scaleFactor) |
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218 { |
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219 qreal factor = matrix().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width(); |
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220 if (factor < 0.07 || factor > 100) |
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221 return; |
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222 |
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223 scale(scaleFactor, scaleFactor); |
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224 } |