#include <QtGui>#include "link.h"#include "node.h"Node::Node(){    myTextColor = Qt::darkGreen;    myOutlineColor = Qt::darkBlue;    myBackgroundColor = Qt::white;    setFlags(ItemIsMovable | ItemIsSelectable);}Node::~Node(){    foreach (Link *link, myLinks)        delete link;}void Node::setText(const QString &text){    prepareGeometryChange();    myText = text;    update();}QString Node::text() const{    return myText;}void Node::setTextColor(const QColor &color){    myTextColor = color;    update();}QColor Node::textColor() const{    return myTextColor;}void Node::setOutlineColor(const QColor &color){    myOutlineColor = color;    update();}QColor Node::outlineColor() const{    return myOutlineColor;}void Node::setBackgroundColor(const QColor &color){    myBackgroundColor = color;    update();}QColor Node::backgroundColor() const{    return myBackgroundColor;}void Node::addLink(Link *link){    myLinks.insert(link);}void Node::removeLink(Link *link){    myLinks.remove(link);}QRectF Node::boundingRect() const{    const int Margin = 1;    return outlineRect().adjusted(-Margin, -Margin, +Margin, +Margin);}QPainterPath Node::shape() const{    QRectF rect = outlineRect();    QPainterPath path;    path.addRoundRect(rect, roundness(rect.width()),                      roundness(rect.height()));    return path;}void Node::paint(QPainter *painter,                 const QStyleOptionGraphicsItem *option,                 QWidget * /* widget */){    QPen pen(myOutlineColor);    if (option->state & QStyle::State_Selected) {        pen.setStyle(Qt::DotLine);        pen.setWidth(2);    }    painter->setPen(pen);    painter->setBrush(myBackgroundColor);    QRectF rect = outlineRect();    painter->drawRoundRect(rect, roundness(rect.width()),                           roundness(rect.height()));    painter->setPen(myTextColor);    painter->drawText(rect, Qt::AlignCenter, myText);}void Node::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event){    QString text = QInputDialog::getText(event->widget(),                           tr("Edit Text"), tr("Enter new text:"),                           QLineEdit::Normal, myText);    if (!text.isEmpty())        setText(text);}QVariant Node::itemChange(GraphicsItemChange change,                          const QVariant &value){    if (change == ItemPositionHasChanged) {        foreach (Link *link, myLinks)            link->trackNodes();    }    return QGraphicsItem::itemChange(change, value);}QRectF Node::outlineRect() const{    const int Padding = 8;    QFontMetricsF metrics = qApp->font();    QRectF rect = metrics.boundingRect(myText);    rect.adjust(-Padding, -Padding, +Padding, +Padding);    rect.translate(-rect.center());    return rect;}int Node::roundness(double size) const{    const int Diameter = 12;    return 100 * Diameter / int(size);}