pyqtgraph/graphicsItems/GridItem.py

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from pyqtgraph.Qt import QtGui, QtCore
from UIGraphicsItem import *
import numpy as np
from pyqtgraph.Point import Point
__all__ = ['GridItem']
class GridItem(UIGraphicsItem):
"""
**Bases:** `UIGraphicsItem <pyqtgraph.UIGraphicsItem>'
Displays a rectangular grid of lines indicating major divisions within a coordinate system.
Automatically determines what divisions to use.
"""
def __init__(self):
UIGraphicsItem.__init__(self)
#QtGui.QGraphicsItem.__init__(self, *args)
#self.setFlag(QtGui.QGraphicsItem.ItemClipsToShape)
#self.setCacheMode(QtGui.QGraphicsItem.DeviceCoordinateCache)
self.picture = None
def viewChangedEvent(self):
self.picture = None
#UIGraphicsItem.viewRangeChanged(self)
#self.update()
def paint(self, p, opt, widget):
#p.setPen(QtGui.QPen(QtGui.QColor(100, 100, 100)))
#p.drawRect(self.boundingRect())
#UIGraphicsItem.paint(self, p, opt, widget)
### draw picture
if self.picture is None:
#print "no pic, draw.."
self.generatePicture()
p.drawPicture(QtCore.QPointF(0, 0), self.picture)
#p.setPen(QtGui.QPen(QtGui.QColor(255,0,0)))
#p.drawLine(0, -100, 0, 100)
#p.drawLine(-100, 0, 100, 0)
#print "drawing Grid."
def generatePicture(self):
self.picture = QtGui.QPicture()
p = QtGui.QPainter()
p.begin(self.picture)
dt = self.viewTransform().inverted()[0]
vr = self.getViewWidget().rect()
unit = self.pixelWidth(), self.pixelHeight()
dim = [vr.width(), vr.height()]
lvr = self.boundingRect()
ul = np.array([lvr.left(), lvr.top()])
br = np.array([lvr.right(), lvr.bottom()])
texts = []
if ul[1] > br[1]:
x = ul[1]
ul[1] = br[1]
br[1] = x
for i in [2,1,0]: ## Draw three different scales of grid
dist = br-ul
nlTarget = 10.**i
d = 10. ** np.floor(np.log10(abs(dist/nlTarget))+0.5)
ul1 = np.floor(ul / d) * d
br1 = np.ceil(br / d) * d
dist = br1-ul1
nl = (dist / d) + 0.5
#print "level", i
#print " dim", dim
#print " dist", dist
#print " d", d
#print " nl", nl
for ax in range(0,2): ## Draw grid for both axes
ppl = dim[ax] / nl[ax]
c = np.clip(3.*(ppl-3), 0., 30.)
linePen = QtGui.QPen(QtGui.QColor(255, 255, 255, c))
textPen = QtGui.QPen(QtGui.QColor(255, 255, 255, c*2))
#linePen.setCosmetic(True)
#linePen.setWidth(1)
bx = (ax+1) % 2
for x in range(0, int(nl[ax])):
linePen.setCosmetic(False)
if ax == 0:
linePen.setWidthF(self.pixelWidth())
#print "ax 0 height", self.pixelHeight()
else:
linePen.setWidthF(self.pixelHeight())
#print "ax 1 width", self.pixelWidth()
p.setPen(linePen)
p1 = np.array([0.,0.])
p2 = np.array([0.,0.])
p1[ax] = ul1[ax] + x * d[ax]
p2[ax] = p1[ax]
p1[bx] = ul[bx]
p2[bx] = br[bx]
## don't draw lines that are out of bounds.
if p1[ax] < min(ul[ax], br[ax]) or p1[ax] > max(ul[ax], br[ax]):
continue
p.drawLine(QtCore.QPointF(p1[0], p1[1]), QtCore.QPointF(p2[0], p2[1]))
if i < 2:
p.setPen(textPen)
if ax == 0:
x = p1[0] + unit[0]
y = ul[1] + unit[1] * 8.
else:
x = ul[0] + unit[0]*3
y = p1[1] + unit[1]
texts.append((QtCore.QPointF(x, y), "%g"%p1[ax]))
tr = self.deviceTransform()
#tr.scale(1.5, 1.5)
p.setWorldTransform(tr.inverted()[0])
for t in texts:
x = tr.map(t[0]) + Point(0.5, 0.5)
p.drawText(x, t[1])
p.end()