--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/examples/graphicsview/elasticnodes/graphwidget.cpp Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,224 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the examples of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "graphwidget.h"
+#include "edge.h"
+#include "node.h"
+
+#include <QDebug>
+#include <QGraphicsScene>
+#include <QWheelEvent>
+
+#include <math.h>
+
+GraphWidget::GraphWidget()
+ : timerId(0)
+{
+ QGraphicsScene *scene = new QGraphicsScene(this);
+ scene->setItemIndexMethod(QGraphicsScene::NoIndex);
+ scene->setSceneRect(-200, -200, 400, 400);
+ setScene(scene);
+ setCacheMode(CacheBackground);
+ setViewportUpdateMode(BoundingRectViewportUpdate);
+ setRenderHint(QPainter::Antialiasing);
+ setTransformationAnchor(AnchorUnderMouse);
+ setResizeAnchor(AnchorViewCenter);
+
+ Node *node1 = new Node(this);
+ Node *node2 = new Node(this);
+ Node *node3 = new Node(this);
+ Node *node4 = new Node(this);
+ centerNode = new Node(this);
+ Node *node6 = new Node(this);
+ Node *node7 = new Node(this);
+ Node *node8 = new Node(this);
+ Node *node9 = new Node(this);
+ scene->addItem(node1);
+ scene->addItem(node2);
+ scene->addItem(node3);
+ scene->addItem(node4);
+ scene->addItem(centerNode);
+ scene->addItem(node6);
+ scene->addItem(node7);
+ scene->addItem(node8);
+ scene->addItem(node9);
+ scene->addItem(new Edge(node1, node2));
+ scene->addItem(new Edge(node2, node3));
+ scene->addItem(new Edge(node2, centerNode));
+ scene->addItem(new Edge(node3, node6));
+ scene->addItem(new Edge(node4, node1));
+ scene->addItem(new Edge(node4, centerNode));
+ scene->addItem(new Edge(centerNode, node6));
+ scene->addItem(new Edge(centerNode, node8));
+ scene->addItem(new Edge(node6, node9));
+ scene->addItem(new Edge(node7, node4));
+ scene->addItem(new Edge(node8, node7));
+ scene->addItem(new Edge(node9, node8));
+
+ node1->setPos(-50, -50);
+ node2->setPos(0, -50);
+ node3->setPos(50, -50);
+ node4->setPos(-50, 0);
+ centerNode->setPos(0, 0);
+ node6->setPos(50, 0);
+ node7->setPos(-50, 50);
+ node8->setPos(0, 50);
+ node9->setPos(50, 50);
+
+ scale(qreal(0.8), qreal(0.8));
+ setMinimumSize(400, 400);
+ setWindowTitle(tr("Elastic Nodes"));
+}
+
+void GraphWidget::itemMoved()
+{
+ if (!timerId)
+ timerId = startTimer(1000 / 25);
+}
+
+void GraphWidget::keyPressEvent(QKeyEvent *event)
+{
+ switch (event->key()) {
+ case Qt::Key_Up:
+ centerNode->moveBy(0, -20);
+ break;
+ case Qt::Key_Down:
+ centerNode->moveBy(0, 20);
+ break;
+ case Qt::Key_Left:
+ centerNode->moveBy(-20, 0);
+ break;
+ case Qt::Key_Right:
+ centerNode->moveBy(20, 0);
+ break;
+ case Qt::Key_Plus:
+ scaleView(qreal(1.2));
+ break;
+ case Qt::Key_Minus:
+ scaleView(1 / qreal(1.2));
+ break;
+ case Qt::Key_Space:
+ case Qt::Key_Enter:
+ foreach (QGraphicsItem *item, scene()->items()) {
+ if (qgraphicsitem_cast<Node *>(item))
+ item->setPos(-150 + qrand() % 300, -150 + qrand() % 300);
+ }
+ break;
+ default:
+ QGraphicsView::keyPressEvent(event);
+ }
+}
+
+void GraphWidget::timerEvent(QTimerEvent *event)
+{
+ Q_UNUSED(event);
+
+ QList<Node *> nodes;
+ foreach (QGraphicsItem *item, scene()->items()) {
+ if (Node *node = qgraphicsitem_cast<Node *>(item))
+ nodes << node;
+ }
+
+ foreach (Node *node, nodes)
+ node->calculateForces();
+
+ bool itemsMoved = false;
+ foreach (Node *node, nodes) {
+ if (node->advance())
+ itemsMoved = true;
+ }
+
+ if (!itemsMoved) {
+ killTimer(timerId);
+ timerId = 0;
+ }
+}
+
+void GraphWidget::wheelEvent(QWheelEvent *event)
+{
+ scaleView(pow((double)2, -event->delta() / 240.0));
+}
+
+void GraphWidget::drawBackground(QPainter *painter, const QRectF &rect)
+{
+ Q_UNUSED(rect);
+
+ // Shadow
+ QRectF sceneRect = this->sceneRect();
+ QRectF rightShadow(sceneRect.right(), sceneRect.top() + 5, 5, sceneRect.height());
+ QRectF bottomShadow(sceneRect.left() + 5, sceneRect.bottom(), sceneRect.width(), 5);
+ if (rightShadow.intersects(rect) || rightShadow.contains(rect))
+ painter->fillRect(rightShadow, Qt::darkGray);
+ if (bottomShadow.intersects(rect) || bottomShadow.contains(rect))
+ painter->fillRect(bottomShadow, Qt::darkGray);
+
+ // Fill
+ QLinearGradient gradient(sceneRect.topLeft(), sceneRect.bottomRight());
+ gradient.setColorAt(0, Qt::white);
+ gradient.setColorAt(1, Qt::lightGray);
+ painter->fillRect(rect.intersect(sceneRect), gradient);
+ painter->setBrush(Qt::NoBrush);
+ painter->drawRect(sceneRect);
+
+ // Text
+ QRectF textRect(sceneRect.left() + 4, sceneRect.top() + 4,
+ sceneRect.width() - 4, sceneRect.height() - 4);
+ QString message(tr("Click and drag the nodes around, and zoom with the mouse "
+ "wheel or the '+' and '-' keys"));
+
+ QFont font = painter->font();
+ font.setBold(true);
+ font.setPointSize(14);
+ painter->setFont(font);
+ painter->setPen(Qt::lightGray);
+ painter->drawText(textRect.translated(2, 2), message);
+ painter->setPen(Qt::black);
+ painter->drawText(textRect, message);
+}
+
+void GraphWidget::scaleView(qreal scaleFactor)
+{
+ qreal factor = matrix().scale(scaleFactor, scaleFactor).mapRect(QRectF(0, 0, 1, 1)).width();
+ if (factor < 0.07 || factor > 100)
+ return;
+
+ scale(scaleFactor, scaleFactor);
+}