--- a/examples/graphicsview/elasticnodes/node.cpp Wed Jun 23 19:07:03 2010 +0300
+++ b/examples/graphicsview/elasticnodes/node.cpp Tue Jul 06 15:10:48 2010 +0300
@@ -6,35 +6,34 @@
**
** 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.
+** $QT_BEGIN_LICENSE:BSD$
+** You may use this file under the terms of the BSD license as follows:
**
-** 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.
+** "Redistribution and use in source and binary forms, with or without
+** modification, are permitted provided that the following conditions are
+** met:
+** * Redistributions of source code must retain the above copyright
+** notice, this list of conditions and the following disclaimer.
+** * Redistributions in binary form must reproduce the above copyright
+** notice, this list of conditions and the following disclaimer in
+** the documentation and/or other materials provided with the
+** distribution.
+** * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
+** the names of its contributors may be used to endorse or promote
+** products derived from this software without specific prior written
+** permission.
**
-**
-**
-**
-**
-**
-**
-**
+** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
** $QT_END_LICENSE$
**
****************************************************************************/
@@ -48,6 +47,7 @@
#include "node.h"
#include "graphwidget.h"
+//! [0]
Node::Node(GraphWidget *graphWidget)
: graph(graphWidget)
{
@@ -56,7 +56,9 @@
setCacheMode(DeviceCoordinateCache);
setZValue(-1);
}
+//! [0]
+//! [1]
void Node::addEdge(Edge *edge)
{
edgeList << edge;
@@ -67,14 +69,18 @@
{
return edgeList;
}
+//! [1]
+//! [2]
void Node::calculateForces()
{
if (!scene() || scene()->mouseGrabberItem() == this) {
newPos = pos();
return;
}
-
+//! [2]
+
+//! [3]
// Sum up all forces pushing this item away
qreal xvel = 0;
qreal yvel = 0;
@@ -83,37 +89,45 @@
if (!node)
continue;
- QLineF line(mapFromItem(node, 0, 0), QPointF(0, 0));
- qreal dx = line.dx();
- qreal dy = line.dy();
+ QPointF vec = mapToItem(node, 0, 0);
+ qreal dx = vec.x();
+ qreal dy = vec.y();
double l = 2.0 * (dx * dx + dy * dy);
if (l > 0) {
xvel += (dx * 150.0) / l;
yvel += (dy * 150.0) / l;
}
}
+//! [3]
+//! [4]
// Now subtract all forces pulling items together
double weight = (edgeList.size() + 1) * 10;
foreach (Edge *edge, edgeList) {
- QPointF pos;
+ QPointF vec;
if (edge->sourceNode() == this)
- pos = mapFromItem(edge->destNode(), 0, 0);
+ vec = mapToItem(edge->destNode(), 0, 0);
else
- pos = mapFromItem(edge->sourceNode(), 0, 0);
- xvel += pos.x() / weight;
- yvel += pos.y() / weight;
+ vec = mapToItem(edge->sourceNode(), 0, 0);
+ xvel -= vec.x() / weight;
+ yvel -= vec.y() / weight;
}
-
+//! [4]
+
+//! [5]
if (qAbs(xvel) < 0.1 && qAbs(yvel) < 0.1)
xvel = yvel = 0;
+//! [5]
+//! [6]
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));
}
+//! [6]
+//! [7]
bool Node::advance()
{
if (newPos == pos())
@@ -122,21 +136,27 @@
setPos(newPos);
return true;
}
+//! [7]
+//! [8]
QRectF Node::boundingRect() const
{
qreal adjust = 2;
return QRectF(-10 - adjust, -10 - adjust,
23 + adjust, 23 + adjust);
}
+//! [8]
+//! [9]
QPainterPath Node::shape() const
{
QPainterPath path;
path.addEllipse(-10, -10, 20, 20);
return path;
}
+//! [9]
+//! [10]
void Node::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *)
{
painter->setPen(Qt::NoPen);
@@ -157,7 +177,9 @@
painter->setPen(QPen(Qt::black, 0));
painter->drawEllipse(-10, -10, 20, 20);
}
+//! [10]
+//! [11]
QVariant Node::itemChange(GraphicsItemChange change, const QVariant &value)
{
switch (change) {
@@ -172,7 +194,9 @@
return QGraphicsItem::itemChange(change, value);
}
+//! [11]
+//! [12]
void Node::mousePressEvent(QGraphicsSceneMouseEvent *event)
{
update();
@@ -184,3 +208,4 @@
update();
QGraphicsItem::mouseReleaseEvent(event);
}
+//! [12]