source: trunk/examples/graphicsview/elasticnodes/graphwidget.cpp@ 490

Last change on this file since 490 was 2, checked in by Dmitry A. Kuminov, 16 years ago

Initially imported qt-all-opensource-src-4.5.1 from Trolltech.
File size: 7.1 KB
Line 
1/****************************************************************************
2**
3** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
4** Contact: Qt Software Information (qt-info@nokia.com)
5**
6** This file is part of the examples of the Qt Toolkit.
7**
8** $QT_BEGIN_LICENSE:LGPL$
9** Commercial Usage
10** Licensees holding valid Qt Commercial licenses may use this file in
11** accordance with the Qt Commercial License Agreement provided with the
12** Software or, alternatively, in accordance with the terms contained in
13** a written agreement between you and Nokia.
14**
15** GNU Lesser General Public License Usage
16** Alternatively, this file may be used under the terms of the GNU Lesser
17** General Public License version 2.1 as published by the Free Software
18** Foundation and appearing in the file LICENSE.LGPL included in the
19** packaging of this file. Please review the following information to
20** ensure the GNU Lesser General Public License version 2.1 requirements
21** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
22**
23** In addition, as a special exception, Nokia gives you certain
24** additional rights. These rights are described in the Nokia Qt LGPL
25** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
26** package.
27**
28** GNU General Public License Usage
29** Alternatively, this file may be used under the terms of the GNU
30** General Public License version 3.0 as published by the Free Software
31** Foundation and appearing in the file LICENSE.GPL included in the
32** packaging of this file. Please review the following information to
33** ensure the GNU General Public License version 3.0 requirements will be
34** met: http://www.gnu.org/copyleft/gpl.html.
35**
36** If you are unsure which license is appropriate for your use, please
37** contact the sales department at qt-sales@nokia.com.
38** $QT_END_LICENSE$
39**
40****************************************************************************/
41
42#include "graphwidget.h"
43#include "edge.h"
44#include "node.h"
45
46#include <QDebug>
47#include <QGraphicsScene>
48#include <QWheelEvent>
49
50#include <math.h>
51
52GraphWidget::GraphWidget()
53 : timerId(0)
54{
55 QGraphicsScene *scene = new QGraphicsScene(this);
56 scene->setItemIndexMethod(QGraphicsScene::NoIndex);
57 scene->setSceneRect(-200, -200, 400, 400);
58 setScene(scene);
59 setCacheMode(CacheBackground);
60 setViewportUpdateMode(BoundingRectViewportUpdate);
61 setRenderHint(QPainter::Antialiasing);
62 setTransformationAnchor(AnchorUnderMouse);
63 setResizeAnchor(AnchorViewCenter);
64
65 Node *node1 = new Node(this);
66 Node *node2 = new Node(this);
67 Node *node3 = new Node(this);
68 Node *node4 = new Node(this);
69 centerNode = new Node(this);
70 Node *node6 = new Node(this);
71 Node *node7 = new Node(this);
72 Node *node8 = new Node(this);
73 Node *node9 = new Node(this);
74 scene->addItem(node1);
75 scene->addItem(node2);
76 scene->addItem(node3);
77 scene->addItem(node4);
78 scene->addItem(centerNode);
79 scene->addItem(node6);
80 scene->addItem(node7);
81 scene->addItem(node8);
82 scene->addItem(node9);
83 scene->addItem(new Edge(node1, node2));
84 scene->addItem(new Edge(node2, node3));
85 scene->addItem(new Edge(node2, centerNode));
86 scene->addItem(new Edge(node3, node6));
87 scene->addItem(new Edge(node4, node1));
88 scene->addItem(new Edge(node4, centerNode));
89 scene->addItem(new Edge(centerNode, node6));
90 scene->addItem(new Edge(centerNode, node8));
91 scene->addItem(new Edge(node6, node9));
92 scene->addItem(new Edge(node7, node4));
93 scene->addItem(new Edge(node8, node7));
94 scene->addItem(new Edge(node9, node8));
95
96 node1->setPos(-50, -50);
97 node2->setPos(0, -50);
98 node3->setPos(50, -50);
99 node4->setPos(-50, 0);
100 centerNode->setPos(0, 0);
101 node6->setPos(50, 0);
102 node7->setPos(-50, 50);
103 node8->setPos(0, 50);
104 node9->setPos(50, 50);
105
106 scale(qreal(0.8), qreal(0.8));
107 setMinimumSize(400, 400);
108 setWindowTitle(tr("Elastic Nodes"));
109}
110
111void GraphWidget::itemMoved()
112{
113 if (!timerId)
114 timerId = startTimer(1000 / 25);
115}
116
117void GraphWidget::keyPressEvent(QKeyEvent *event)
118{
119 switch (event->key()) {
120 case Qt::Key_Up:
121 centerNode->moveBy(0, -20);
122 break;
123 case Qt::Key_Down:
124 centerNode->moveBy(0, 20);
125 break;
126 case Qt::Key_Left:
127 centerNode->moveBy(-20, 0);
128 break;
129 case Qt::Key_Right:
130 centerNode->moveBy(20, 0);
131 break;
132 case Qt::Key_Plus:
133 scaleView(qreal(1.2));
134 break;
135 case Qt::Key_Minus:
136 scaleView(1 / qreal(1.2));
137 break;
138 case Qt::Key_Space:
139 case Qt::Key_Enter:
140 foreach (QGraphicsItem *item, scene()->items()) {
141 if (qgraphicsitem_cast<Node *>(item))
142 item->setPos(-150 + qrand() % 300, -150 + qrand() % 300);
143 }
144 break;
145 default:
146 QGraphicsView::keyPressEvent(event);
147 }
148}
149
150void GraphWidget::timerEvent(QTimerEvent *event)
151{
152 Q_UNUSED(event);
153
154 QList<Node *> nodes;
155 foreach (QGraphicsItem *item, scene()->items()) {
156 if (Node *node = qgraphicsitem_cast<Node *>(item))
157 nodes << node;
158 }
159
160 foreach (Node *node, nodes)
161 node->calculateForces();
162
163 bool itemsMoved = false;
164 foreach (Node *node, nodes) {
165 if (node->advance())
166 itemsMoved = true;
167 }
168
169 if (!itemsMoved) {
170 killTimer(timerId);
171 timerId = 0;
172 }
173}
174
175void GraphWidget::wheelEvent(QWheelEvent *event)
176{
177 scaleView(pow((double)2, -event->delta() / 240.0));
178}
179
180void GraphWidget::drawBackground(QPainter *painter, const QRectF &rect)
181{
182 Q_UNUSED(rect);
183
184 // Shadow
185 QRectF sceneRect = this->sceneRect();
186 QRectF rightShadow(sceneRect.right(), sceneRect.top() + 5, 5, sceneRect.height());
187 QRectF bottomShadow(sceneRect.left() + 5, sceneRect.bottom(), sceneRect.width(), 5);
188 if (rightShadow.intersects(rect) || rightShadow.contains(rect))
189 painter->fillRect(rightShadow, Qt::darkGray);
190 if (bottomShadow.intersects(rect) || bottomShadow.contains(rect))
191 painter->fillRect(bottomShadow, Qt::darkGray);
192
193 // Fill
194 QLinearGradient gradient(sceneRect.topLeft(), sceneRect.bottomRight());
195 gradient.setColorAt(0, Qt::white);
196 gradient.setColorAt(1, Qt::lightGray);
197 painter->fillRect(rect.intersect(sceneRect), gradient);
198 painter->setBrush(Qt::NoBrush);
199 painter->drawRect(sceneRect);
200
201 // Text
202 QRectF textRect(sceneRect.left() + 4, sceneRect.top() + 4,
203 sceneRect.width() - 4, sceneRect.height() - 4);
204 QString message(tr("Click and drag the nodes around, and zoom with the mouse "
205 "wheel or the '+' and '-' keys"));
206
207 QFont font = painter->font();
208 font.setBold(true);
209 font.setPointSize(14);
210 painter->setFont(font);
211 painter->setPen(Qt::lightGray);
212 painter->drawText(textRect.translated(2, 2), message);
213 painter->setPen(Qt::black);
214 painter->drawText(textRect, message);
215}
216
217void GraphWidget::scaleView(qreal scaleFactor)
218{
219 qreal factor = matrix().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();
220 if (factor < 0.07 || factor > 100)
221 return;
222
223 scale(scaleFactor, scaleFactor);
224}
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