summaryrefslogtreecommitdiffstats
path: root/examples/graphicsview/elasticnodes/node.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'examples/graphicsview/elasticnodes/node.cpp')
-rw-r--r--examples/graphicsview/elasticnodes/node.cpp185
1 files changed, 185 insertions, 0 deletions
diff --git a/examples/graphicsview/elasticnodes/node.cpp b/examples/graphicsview/elasticnodes/node.cpp
new file mode 100644
index 0000000..6942fa0
--- /dev/null
+++ b/examples/graphicsview/elasticnodes/node.cpp
@@ -0,0 +1,185 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (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 either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** 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 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QGraphicsScene>
+#include <QGraphicsSceneMouseEvent>
+#include <QPainter>
+#include <QStyleOption>
+
+#include "edge.h"
+#include "node.h"
+#include "graphwidget.h"
+
+Node::Node(GraphWidget *graphWidget)
+ : graph(graphWidget)
+{
+ setFlag(ItemIsMovable);
+ setCacheMode(DeviceCoordinateCache);
+ setZValue(1);
+}
+
+void Node::addEdge(Edge *edge)
+{
+ edgeList << edge;
+ edge->adjust();
+}
+
+QList<Edge *> Node::edges() const
+{
+ return edgeList;
+}
+
+void Node::calculateForces()
+{
+ if (!scene() || scene()->mouseGrabberItem() == this) {
+ newPos = pos();
+ return;
+ }
+
+ // Sum up all forces pushing this item away
+ qreal xvel = 0;
+ qreal yvel = 0;
+ foreach (QGraphicsItem *item, scene()->items()) {
+ Node *node = qgraphicsitem_cast<Node *>(item);
+ if (!node)
+ continue;
+
+ QLineF line(mapFromItem(node, 0, 0), QPointF(0, 0));
+ qreal dx = line.dx();
+ qreal dy = line.dy();
+ double l = 2.0 * (dx * dx + dy * dy);
+ if (l > 0) {
+ xvel += (dx * 150.0) / l;
+ yvel += (dy * 150.0) / l;
+ }
+ }
+
+ // Now subtract all forces pulling items together
+ double weight = (edgeList.size() + 1) * 10;
+ foreach (Edge *edge, edgeList) {
+ QPointF pos;
+ if (edge->sourceNode() == this)
+ pos = mapFromItem(edge->destNode(), 0, 0);
+ else
+ pos = mapFromItem(edge->sourceNode(), 0, 0);
+ xvel += pos.x() / weight;
+ yvel += pos.y() / weight;
+ }
+
+ if (qAbs(xvel) < 0.1 && qAbs(yvel) < 0.1)
+ xvel = yvel = 0;
+
+ QRectF sceneRect = scene()->sceneRect();
+ newPos = pos() + QPointF(xvel, yvel);
+ newPos.setX(qMin(qMax(newPos.x(), sceneRect.left() + 10), sceneRect.right() - 10));
+ newPos.setY(qMin(qMax(newPos.y(), sceneRect.top() + 10), sceneRect.bottom() - 10));
+}
+
+bool Node::advance()
+{
+ if (newPos == pos())
+ return false;
+
+ setPos(newPos);
+ return true;
+}
+
+QRectF Node::boundingRect() const
+{
+ qreal adjust = 2;
+ return QRectF(-10 - adjust, -10 - adjust,
+ 23 + adjust, 23 + adjust);
+}
+
+QPainterPath Node::shape() const
+{
+ QPainterPath path;
+ path.addEllipse(-10, -10, 20, 20);
+ return path;
+}
+
+void Node::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *)
+{
+ painter->setPen(Qt::NoPen);
+ painter->setBrush(Qt::darkGray);
+ painter->drawEllipse(-7, -7, 20, 20);
+
+ QRadialGradient gradient(-3, -3, 10);
+ if (option->state & QStyle::State_Sunken) {
+ gradient.setCenter(3, 3);
+ gradient.setFocalPoint(3, 3);
+ gradient.setColorAt(1, QColor(Qt::yellow).light(120));
+ gradient.setColorAt(0, QColor(Qt::darkYellow).light(120));
+ } else {
+ gradient.setColorAt(0, Qt::yellow);
+ gradient.setColorAt(1, Qt::darkYellow);
+ }
+ painter->setBrush(gradient);
+ painter->setPen(QPen(Qt::black, 0));
+ painter->drawEllipse(-10, -10, 20, 20);
+}
+
+QVariant Node::itemChange(GraphicsItemChange change, const QVariant &value)
+{
+ switch (change) {
+ case ItemPositionHasChanged:
+ foreach (Edge *edge, edgeList)
+ edge->adjust();
+ graph->itemMoved();
+ break;
+ default:
+ break;
+ };
+
+ return QGraphicsItem::itemChange(change, value);
+}
+
+void Node::mousePressEvent(QGraphicsSceneMouseEvent *event)
+{
+ update();
+ QGraphicsItem::mousePressEvent(event);
+}
+
+void Node::mouseReleaseEvent(QGraphicsSceneMouseEvent *event)
+{
+ update();
+ QGraphicsItem::mouseReleaseEvent(event);
+}