Source code for pyqtgraph.graphicsItems.ScaleBar

from .. import functions as fn
from .. import getConfigOption
from ..Point import Point
from ..Qt import QtCore, QtWidgets
from .GraphicsObject import *
from .GraphicsWidgetAnchor import *
from .TextItem import TextItem

__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 is None: offset = (0,0) self.offset = offset = QtWidgets.QGraphicsRectItem() 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(), 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