summaryrefslogtreecommitdiffstats
path: root/examples/graphicsview/elasticnodes/edge.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'examples/graphicsview/elasticnodes/edge.cpp')
-rw-r--r--examples/graphicsview/elasticnodes/edge.cpp144
1 files changed, 144 insertions, 0 deletions
diff --git a/examples/graphicsview/elasticnodes/edge.cpp b/examples/graphicsview/elasticnodes/edge.cpp
new file mode 100644
index 0000000..4018c25
--- /dev/null
+++ b/examples/graphicsview/elasticnodes/edge.cpp
@@ -0,0 +1,144 @@
+/****************************************************************************
+**
+** 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 <QPainter>
+
+#include "edge.h"
+#include "node.h"
+
+#include <math.h>
+
+static const double Pi = 3.14159265358979323846264338327950288419717;
+static double TwoPi = 2.0 * Pi;
+
+Edge::Edge(Node *sourceNode, Node *destNode)
+ : arrowSize(10)
+{
+ setAcceptedMouseButtons(0);
+ source = sourceNode;
+ dest = destNode;
+ source->addEdge(this);
+ dest->addEdge(this);
+ adjust();
+}
+
+Edge::~Edge()
+{
+}
+
+Node *Edge::sourceNode() const
+{
+ return source;
+}
+
+void Edge::setSourceNode(Node *node)
+{
+ source = node;
+ adjust();
+}
+
+Node *Edge::destNode() const
+{
+ return dest;
+}
+
+void Edge::setDestNode(Node *node)
+{
+ dest = node;
+ adjust();
+}
+
+void Edge::adjust()
+{
+ if (!source || !dest)
+ return;
+
+ QLineF line(mapFromItem(source, 0, 0), mapFromItem(dest, 0, 0));
+ qreal length = line.length();
+ QPointF edgeOffset((line.dx() * 10) / length, (line.dy() * 10) / length);
+
+ prepareGeometryChange();
+ sourcePoint = line.p1() + edgeOffset;
+ destPoint = line.p2() - edgeOffset;
+}
+
+QRectF Edge::boundingRect() const
+{
+ if (!source || !dest)
+ return QRectF();
+
+ qreal penWidth = 1;
+ qreal extra = (penWidth + arrowSize) / 2.0;
+
+ return QRectF(sourcePoint, QSizeF(destPoint.x() - sourcePoint.x(),
+ destPoint.y() - sourcePoint.y()))
+ .normalized()
+ .adjusted(-extra, -extra, extra, extra);
+}
+
+void Edge::paint(QPainter *painter, const QStyleOptionGraphicsItem *, QWidget *)
+{
+ if (!source || !dest)
+ return;
+
+ // Draw the line itself
+ QLineF line(sourcePoint, destPoint);
+ painter->setPen(QPen(Qt::black, 1, Qt::SolidLine, Qt::RoundCap, Qt::RoundJoin));
+ painter->drawLine(line);
+
+ // Draw the arrows if there's enough room
+ double angle = ::acos(line.dx() / line.length());
+ if (line.dy() >= 0)
+ angle = TwoPi - angle;
+
+ QPointF sourceArrowP1 = sourcePoint + QPointF(sin(angle + Pi / 3) * arrowSize,
+ cos(angle + Pi / 3) * arrowSize);
+ QPointF sourceArrowP2 = sourcePoint + QPointF(sin(angle + Pi - Pi / 3) * arrowSize,
+ cos(angle + Pi - Pi / 3) * arrowSize);
+ QPointF destArrowP1 = destPoint + QPointF(sin(angle - Pi / 3) * arrowSize,
+ cos(angle - Pi / 3) * arrowSize);
+ QPointF destArrowP2 = destPoint + QPointF(sin(angle - Pi + Pi / 3) * arrowSize,
+ cos(angle - Pi + Pi / 3) * arrowSize);
+
+ painter->setBrush(Qt::black);
+ painter->drawPolygon(QPolygonF() << line.p1() << sourceArrowP1 << sourceArrowP2);
+ painter->drawPolygon(QPolygonF() << line.p2() << destArrowP1 << destArrowP2);
+}