void NodeItem::moveBy(double dx, double dy)
{
QCanvasEllipse::moveBy( dx, dy ); // 使用父類別的moveBy函數
QPtrListIterator<EdgeItem> it1( inList ); // 設定it1為指到QPtrList的指標變數
EdgeItem *edge;
// 若it1指到的位置存放的EdgeItem的指標不是0時，則執行大括號內的指令,直到edge為空指標
while (( edge = it1.current() )) {
++it1;
edge->setToPoint( int(x()), int(y()) );
}
QPtrListIterator<EdgeItem> it2( outList );
while (( edge = it2.current() )) {
++it2;
edge->setFromPoint( int(x()), int(y()) );
}
}
QVariant NodeItem::itemChange(GraphicsItemChange change, const QVariant &value)
{
if (change == ItemPositionHasChanged) {
Q3PtrListIterator<EdgeItem> it1( inList );
EdgeItem *edge;
while (( edge = it1.current() )) {
++it1;
edge->setToPoint( int(x()), int(y()) );
}
Q3PtrListIterator<EdgeItem> it2( outList );
while (( edge = it2.current() )) {
++it2;
edge->setFromPoint( int(x()), int(y()) );
}
}
return QGraphicsEllipseItem::itemChange(change, value);
}
