def calculateForces(self):
if not self.scene() or self.scene().mouseGrabberItem() is self:
self.newPos = self.pos()
return
# Sum up all forces pushing this item away.
xvel = 0.0
yvel = 0.0
for item in self.scene().items():
if not isinstance(item, Node):
continue
line = QLineF(self.mapFromItem(item, 0, 0), QPointF(0, 0))
dx = line.dx()
dy = line.dy()
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.
#weight = (len(self.edgeList) + 1) * 100.0
for edge in self.edgeList:
if edge.sourceNode() is self:
pos = self.mapFromItem(edge.destNode(), 0, 0)
else:
weight = edge.weight * 6
pos = self.mapFromItem(edge.sourceNode(), 0, 0)
xvel += pos.x() / weight
yvel += pos.y() / weight
if qAbs(xvel) < 0.1 and qAbs(yvel) < 0.1:
xvel = yvel = 0.0
sceneRect = self.scene().sceneRect()
self.newPos = self.pos() + QPointF(xvel, yvel)
self.newPos.setX(
min(max(self.newPos.x(),
sceneRect.left() + 10),
sceneRect.right() - 10))
self.newPos.setY(
min(max(self.newPos.y(),
sceneRect.top() + 10),
sceneRect.bottom() - 10))
def adjust(self):
if not self.source or not self.dest:
return
line = QLineF(self.mapFromItem(self.source, 0, 0),
self.mapFromItem(self.dest, 0, 0))
length = line.length()
self.prepareGeometryChange()
if length > 20.0:
edgeOffset = QPointF((line.dx() * 10) / length,
(line.dy() * 10) / length)
self.sourcePoint = line.p1() + edgeOffset
self.destPoint = line.p2() - edgeOffset
else:
self.sourcePoint = line.p1()
self.destPoint = line.p1()
def paint(self, painter, option, widget):
if not self.source or not self.dest:
return
# Draw the line itself.
line = QLineF(self.sourcePoint, self.destPoint)
if line.length() == 0.0:
return
palette = QPalette()
self.setZValue(self.state)
if self.state == 3:
pen = QPen(Qt.red, 2, Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin)
if self.state == 2:
pen = QPen(Qt.red, 2, Qt.DashLine, Qt.RoundCap, Qt.RoundJoin)
elif self.state == 1:
pen = QPen(palette.color(QPalette.Disabled, QPalette.WindowText),
0, Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin)
elif self.state == 0:
pen = QPen()
pen.setBrush(QBrush(Qt.NoBrush))
painter.setPen(pen)
painter.drawLine(line)
angle = math.acos(line.dx() / line.length())
if line.dy() >= 0:
angle = Edge.TwoPi - angle
# draw arrowheads
if self.state == 2 or self.state == 3:
# Draw the arrows if there's enough room.
sourceArrowP1 = self.sourcePoint + QPointF(
math.sin(angle + Edge.Pi / 3) * self.arrowSize,
math.cos(angle + Edge.Pi / 3) * self.arrowSize)
sourceArrowP2 = self.sourcePoint + QPointF(
math.sin(angle + Edge.Pi - Edge.Pi / 3) * self.arrowSize,
math.cos(angle + Edge.Pi - Edge.Pi / 3) * self.arrowSize)
destArrowP1 = self.destPoint + QPointF(
math.sin(angle - Edge.Pi / 3) * self.arrowSize,
math.cos(angle - Edge.Pi / 3) * self.arrowSize)
destArrowP2 = self.destPoint + QPointF(
math.sin(angle - Edge.Pi + Edge.Pi / 3) * self.arrowSize,
math.cos(angle - Edge.Pi + Edge.Pi / 3) * self.arrowSize)
painter.setPen(
QPen(Qt.red, 2, Qt.SolidLine, Qt.RoundCap, Qt.RoundJoin))
painter.setBrush(QBrush(Qt.red, Qt.SolidPattern))
painter.drawPolygon(
QPolygonF([line.p1(), sourceArrowP1, sourceArrowP2]))
#painter.drawPolygon(QPolygonF([line.p2(), destArrowP1, destArrowP2]))
if self.state > 0 and self.source > self.dest:
point = QPointF((self.sourcePoint.x() + self.destPoint.x()) / 2,
(self.sourcePoint.y() + self.destPoint.y()) / 2)
point = QPointF(point.x() + math.sin(angle) * 16,
point.y() + math.cos(angle) * 16)
painter.drawText(point, self.text)
