我正在改变悬停时元素的背景位置，它在chrome上运行正常，但是当我在safari上尝试它时，背景会快速上下跳跃，我尝试应用我发现的一些修复一个谷歌搜索，它仍然无法正常工作，这里是代码（html，原始规则，过渡属性和：悬停规则） -
<div class="port-big">
<a class="port-item campbell" href="http://www.campbellmgmt.com/" target="_blank">
<div class="port-img"></div>
<h3 class="port-title">Campbell Property Management</h3>
<img class="port-logo" src="images/campbell-logo-white.png" />
<p class="port-descr">Campbell Property Management was my largest project while I was at Juvo Web. The client was looking to completely update their website and
add some new features. After extensive research on property and real estate UI/UX I designed the new front end and implemented it on their website.</p>
</a>
</div>
.port-img {
overflow: hidden;
width: 100%;
height: 100%;
background-blend-mode: overlay;
background-size: cover;
background-position: center top;
background-position-x: 0%;
background-position-y: 0%;
}
.campbell .port-img {
background-image: url(../../images/campbell-screenshot.png);
background-color: #dd3a00;
}
.port-title, .port-descr, .port-logo, .port-img {
-webkit-transition: all ease-in-out 0.4s,
background-position linear 24s;
transition: all ease-in-out 0.4s,
background-position linear 24s;
}
.port-big .port-item:hover .port-img {
background-position: center bottom;
background-position-x: 0%;
background-position-y: 100%;
}
答案 0 :(得分：2)
我找到了答案，当我将背景位置过渡分离为它自己的规则时，它工作正常，最终看起来像这样 -
#!/usr/bin/env python
import math
from PyQt4 import QtCore, QtGui
from PyQt4.QtGui import QGraphicsView, QGraphicsTextItem
class QEdgeGraphicItem(QtGui.QGraphicsItem):
Type = QtGui.QGraphicsItem.UserType + 2
def __init__(self, sourceNode, destNode, label=None):
super(QEdgeGraphicItem, self).__init__()
self.sourcePoint = QtCore.QPointF()
self.destPoint = QtCore.QPointF()
self.setAcceptedMouseButtons(QtCore.Qt.NoButton)
self.setFlag(QtGui.QGraphicsItem.ItemIsMovable)
self.setFlag(QtGui.QGraphicsItem.ItemSendsGeometryChanges)
# self.setCacheMode(QtGui.QGraphicsItem.DeviceCoordinateCache)
self.source = sourceNode
self.dest = destNode
self.label = QGraphicsTextItem("WHY IN THE HELL IS IT IN 0,0", self)
self.label.setParentItem(self)
self.label.setDefaultTextColor(QtCore.Qt.black)
self.source.addEdge(self)
self.dest.addEdge(self)
self.adjust()
def adjust(self):
if not self.source or not self.dest:
return
line = QtCore.QLineF(self.mapFromItem(self.source, 0, 0),
self.mapFromItem(self.dest, 0, 0))
self.prepareGeometryChange()
self.sourcePoint = line.p1()
self.destPoint = line.p2()
def boundingRect(self):
if not self.source or not self.dest:
return QtCore.QRectF()
extra = 2
return QtCore.QRectF(self.sourcePoint,
QtCore.QSizeF(self.destPoint.x() - self.sourcePoint.x(),
self.destPoint.y() - self.sourcePoint.y())).normalized().adjusted(-extra,
-extra,
extra,
extra)
def paint(self, painter, option, widget):
if not self.source or not self.dest:
return
# Draw the line itself.
line = QtCore.QLineF(self.sourcePoint, self.destPoint)
if line.length() == 0.0:
return
painter.setPen(QtGui.QPen(QtCore.Qt.black, 1, QtCore.Qt.SolidLine,
QtCore.Qt.RoundCap, QtCore.Qt.RoundJoin))
painter.drawLine(line)
painter.setBrush(QtCore.Qt.NoBrush)
painter.setPen(QtCore.Qt.red)
painter.drawRect(self.boundingRect())
print "Edge:"+str(self.scenePos().x()) + " " + str(self.scenePos().y())
class QNodeGraphicItem(QtGui.QGraphicsItem):
Type = QtGui.QGraphicsItem.UserType + 1
def __init__(self, label):
super(QNodeGraphicItem, self).__init__()
# self.graph = graphWidget
self.edgeList = []
self.newPos = QtCore.QPointF()
self.setFlag(QtGui.QGraphicsItem.ItemIsMovable)
self.setFlag(QtGui.QGraphicsItem.ItemSendsGeometryChanges)
# self.setCacheMode(QtGui.QGraphicsItem.DeviceCoordinateCache)
# self.setZValue(1)
self.size = 40
self.border_width = 4
def type(self):
return QNodeGraphicItem.Type
def addEdge(self, edge):
self.edgeList.append(edge)
edge.adjust()
def boundingRect(self):
x_coord = y_coord = (-1*(self.size/2)) - self.border_width
width = height = self.size+23+self.border_width
return QtCore.QRectF(x_coord, y_coord , width,
height)
def paint(self, painter, option, widget):
x_coord = y_coord = -(self.size / 2)
width = height = self.size
painter.save()
painter.setBrush(QtGui.QBrush(QtGui.QColor(100, 0, 200, 127)))
painter.setPen(QtCore.Qt.black)
painter.drawEllipse(x_coord, y_coord, width, height)
painter.restore()
print "Node: " + str(self.scenePos().x()) + " " + str(self.scenePos().y())
def itemChange(self, change, value):
if change == QtGui.QGraphicsItem.ItemPositionHasChanged:
for edge in self.edgeList:
edge.adjust()
return super(QNodeGraphicItem, self).itemChange(change, value)
def mousePressEvent(self, event):
self.update()
super(QNodeGraphicItem, self).mousePressEvent(event)
def mouseReleaseEvent(self, event):
self.update()
super(QNodeGraphicItem, self).mouseReleaseEvent(event)
if __name__ == '__main__':
import sys
app = QtGui.QApplication(sys.argv)
QtCore.qsrand(QtCore.QTime(0, 0, 0).secsTo(QtCore.QTime.currentTime()))
node1 = QNodeGraphicItem("Node1")
node2 = QNodeGraphicItem("Node2")
edge = QEdgeGraphicItem(node1,node2)
view = QGraphicsView()
view.setCacheMode(QtGui.QGraphicsView.CacheBackground)
view.setViewportUpdateMode(QtGui.QGraphicsView.BoundingRectViewportUpdate)
view.setRenderHint(QtGui.QPainter.Antialiasing)
view.setTransformationAnchor(QtGui.QGraphicsView.AnchorUnderMouse)
view.setResizeAnchor(QtGui.QGraphicsView.AnchorViewCenter)
view.scale(0.8, 0.8)
view.setMinimumSize(400, 400)
view.setWindowTitle("Example")
scene = QtGui.QGraphicsScene(view)
scene.setItemIndexMethod(QtGui.QGraphicsScene.NoIndex)
scene.setSceneRect(-400, -400, 800, 800)
view.setScene(scene)
scene.addItem(node1)
scene.addItem(node2)
scene.addItem(edge)
view.show()
sys.exit(app.exec_())