from ..Qt import QtGui, QtCore
from .GraphicsObject import *
from .GraphicsWidgetAnchor import *
from .TextItem import TextItem
import numpy as np
from .. import functions as fn
from .. import getConfigOption
from ..Point import Point
__all__ = ['ScaleBar']
[docs]class ScaleBar(GraphicsObject, GraphicsWidgetAnchor):
"""
Displays a rectangular bar to indicate the relative scale of objects on the view.
"""
[docs] def __init__(self, size, width=5, brush=None, pen=None, suffix='m', offset=None):
GraphicsObject.__init__(self)
GraphicsWidgetAnchor.__init__(self)
self.setFlag(self.GraphicsItemFlag.ItemHasNoContents)
self.setAcceptedMouseButtons(QtCore.Qt.MouseButton.NoButton)
if brush is None:
brush = getConfigOption('foreground')
self.brush = fn.mkBrush(brush)
self.pen = fn.mkPen(pen)
self._width = width
self.size = size
if offset == None:
offset = (0,0)
self.offset = offset
self.bar = QtGui.QGraphicsRectItem()
self.bar.setPen(self.pen)
self.bar.setBrush(self.brush)
self.bar.setParentItem(self)
self.text = TextItem(text=fn.siFormat(size, suffix=suffix), anchor=(0.5,1))
self.text.setParentItem(self)
def parentChanged(self):
view = self.parentItem()
if view is None:
return
view.sigRangeChanged.connect(self.updateBar)
self.updateBar()
def updateBar(self):
view = self.parentItem()
if view is None:
return
p1 = view.mapFromViewToItem(self, QtCore.QPointF(0,0))
p2 = view.mapFromViewToItem(self, QtCore.QPointF(self.size,0))
w = (p2-p1).x()
self.bar.setRect(QtCore.QRectF(-w, 0, w, self._width))
self.text.setPos(-w/2., 0)
def boundingRect(self):
return QtCore.QRectF()
def setParentItem(self, p):
ret = GraphicsObject.setParentItem(self, p)
if self.offset is not None:
offset = Point(self.offset)
anchorx = 1 if offset[0] <= 0 else 0
anchory = 1 if offset[1] <= 0 else 0
anchor = (anchorx, anchory)
self.anchor(itemPos=anchor, parentPos=anchor, offset=offset)
return ret