pyqtgraph/graphicsItems/AxisItem.py

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from pyqtgraph.Qt import QtGui, QtCore
import numpy as np
from pyqtgraph.Point import Point
import pyqtgraph.debug as debug
import weakref
import pyqtgraph.functions as fn
from GraphicsWidget import GraphicsWidget
__all__ = ['AxisItem']
class AxisItem(GraphicsWidget):
def __init__(self, orientation, pen=None, linkView=None, parent=None, maxTickLength=-5, showValues=True):
"""
GraphicsItem showing a single plot axis with ticks, values, and label.
Can be configured to fit on any side of a plot, and can automatically synchronize its displayed scale with ViewBox items.
Ticks can be extended to make a grid.
If maxTickLength is negative, ticks point into the plot.
"""
GraphicsWidget.__init__(self, parent)
self.label = QtGui.QGraphicsTextItem(self)
self.showValues = showValues
self.picture = None
self.orientation = orientation
if orientation not in ['left', 'right', 'top', 'bottom']:
raise Exception("Orientation argument must be one of 'left', 'right', 'top', or 'bottom'.")
if orientation in ['left', 'right']:
#self.setMinimumWidth(25)
#self.setSizePolicy(QtGui.QSizePolicy(
#QtGui.QSizePolicy.Minimum,
#QtGui.QSizePolicy.Expanding
#))
self.label.rotate(-90)
#else:
#self.setMinimumHeight(50)
#self.setSizePolicy(QtGui.QSizePolicy(
#QtGui.QSizePolicy.Expanding,
#QtGui.QSizePolicy.Minimum
#))
#self.drawLabel = False
self.labelText = ''
self.labelUnits = ''
self.labelUnitPrefix=''
self.labelStyle = {'color': '#CCC'}
self.logMode = False
self.textHeight = 18
self.tickLength = maxTickLength
self.scale = 1.0
self.autoScale = True
self.setRange(0, 1)
if pen is None:
pen = QtGui.QPen(QtGui.QColor(100, 100, 100))
self.setPen(pen)
self._linkedView = None
if linkView is not None:
self.linkToView(linkView)
self.showLabel(False)
self.grid = False
#self.setCacheMode(self.DeviceCoordinateCache)
def close(self):
self.scene().removeItem(self.label)
self.label = None
self.scene().removeItem(self)
def setGrid(self, grid):
"""Set the alpha value for the grid, or False to disable."""
self.grid = grid
self.picture = None
self.prepareGeometryChange()
self.update()
def setLogMode(self, log):
self.logMode = log
self.picture = None
self.update()
def resizeEvent(self, ev=None):
#s = self.size()
## Set the position of the label
nudge = 5
br = self.label.boundingRect()
p = QtCore.QPointF(0, 0)
if self.orientation == 'left':
p.setY(int(self.size().height()/2 + br.width()/2))
p.setX(-nudge)
#s.setWidth(10)
elif self.orientation == 'right':
#s.setWidth(10)
p.setY(int(self.size().height()/2 + br.width()/2))
p.setX(int(self.size().width()-br.height()+nudge))
elif self.orientation == 'top':
#s.setHeight(10)
p.setY(-nudge)
p.setX(int(self.size().width()/2. - br.width()/2.))
elif self.orientation == 'bottom':
p.setX(int(self.size().width()/2. - br.width()/2.))
#s.setHeight(10)
p.setY(int(self.size().height()-br.height()+nudge))
#self.label.resize(s)
self.label.setPos(p)
self.picture = None
def showLabel(self, show=True):
#self.drawLabel = show
self.label.setVisible(show)
if self.orientation in ['left', 'right']:
self.setWidth()
else:
self.setHeight()
if self.autoScale:
self.setScale()
def setLabel(self, text=None, units=None, unitPrefix=None, **args):
if text is not None:
self.labelText = text
self.showLabel()
if units is not None:
self.labelUnits = units
self.showLabel()
if unitPrefix is not None:
self.labelUnitPrefix = unitPrefix
if len(args) > 0:
self.labelStyle = args
self.label.setHtml(self.labelString())
self.resizeEvent()
self.picture = None
self.update()
def labelString(self):
if self.labelUnits == '':
if self.scale == 1.0:
units = ''
else:
units = u'(x%g)' % (1.0/self.scale)
else:
#print repr(self.labelUnitPrefix), repr(self.labelUnits)
units = u'(%s%s)' % (self.labelUnitPrefix, self.labelUnits)
s = u'%s %s' % (self.labelText, units)
style = ';'.join(['%s: "%s"' % (k, self.labelStyle[k]) for k in self.labelStyle])
return u"<span style='%s'>%s</span>" % (style, s)
def setHeight(self, h=None):
if h is None:
h = self.textHeight + max(0, self.tickLength)
if self.label.isVisible():
h += self.textHeight
self.setMaximumHeight(h)
self.setMinimumHeight(h)
self.picture = None
def setWidth(self, w=None):
if w is None:
w = max(0, self.tickLength) + 40
if self.label.isVisible():
w += self.textHeight
self.setMaximumWidth(w)
self.setMinimumWidth(w)
def setPen(self, pen):
self.pen = pen
self.picture = None
self.update()
def setScale(self, scale=None):
"""
Set the value scaling for this axis.
The scaling value 1) multiplies the values displayed along the axis
and 2) changes the way units are displayed in the label.
For example:
If the axis spans values from -0.1 to 0.1 and has units set to 'V'
then a scale of 1000 would cause the axis to display values -100 to 100
and the units would appear as 'mV'
If scale is None, then it will be determined automatically based on the current
range displayed by the axis.
"""
if scale is None:
#if self.drawLabel: ## If there is a label, then we are free to rescale the values
if self.label.isVisible():
d = self.range[1] - self.range[0]
#(scale, prefix) = fn.siScale(d / 2.)
(scale, prefix) = fn.siScale(max(abs(self.range[0]), abs(self.range[1])))
if self.labelUnits == '' and prefix in ['k', 'm']: ## If we are not showing units, wait until 1e6 before scaling.
scale = 1.0
prefix = ''
self.setLabel(unitPrefix=prefix)
else:
scale = 1.0
if scale != self.scale:
self.scale = scale
self.setLabel()
self.picture = None
self.update()
def setRange(self, mn, mx):
if mn in [np.nan, np.inf, -np.inf] or mx in [np.nan, np.inf, -np.inf]:
raise Exception("Not setting range to [%s, %s]" % (str(mn), str(mx)))
self.range = [mn, mx]
if self.autoScale:
self.setScale()
self.picture = None
self.update()
def linkedView(self):
"""Return the ViewBox this axis is linked to"""
if self._linkedView is None:
return None
else:
return self._linkedView()
def linkToView(self, view):
oldView = self.linkedView()
self._linkedView = weakref.ref(view)
if self.orientation in ['right', 'left']:
if oldView is not None:
oldView.sigYRangeChanged.disconnect(self.linkedViewChanged)
view.sigYRangeChanged.connect(self.linkedViewChanged)
else:
if oldView is not None:
oldView.sigXRangeChanged.disconnect(self.linkedViewChanged)
view.sigXRangeChanged.connect(self.linkedViewChanged)
def linkedViewChanged(self, view, newRange):
self.setRange(*newRange)
def boundingRect(self):
linkedView = self.linkedView()
if linkedView is None or self.grid is False:
rect = self.mapRectFromParent(self.geometry())
## extend rect if ticks go in negative direction
if self.orientation == 'left':
rect.setRight(rect.right() - min(0,self.tickLength))
elif self.orientation == 'right':
rect.setLeft(rect.left() + min(0,self.tickLength))
elif self.orientation == 'top':
rect.setBottom(rect.bottom() - min(0,self.tickLength))
elif self.orientation == 'bottom':
rect.setTop(rect.top() + min(0,self.tickLength))
return rect
else:
return self.mapRectFromParent(self.geometry()) | linkedView.mapRectToItem(self, linkedView.boundingRect())
def paint(self, p, opt, widget):
if self.picture is None:
self.picture = QtGui.QPicture()
painter = QtGui.QPainter(self.picture)
try:
self.drawPicture(painter)
finally:
painter.end()
self.picture.play(p)
def tickSpacing(self, minVal, maxVal, size):
"""Return values describing the desired spacing and offset of ticks.
This method is called whenever the axis needs to be redrawn and is a
good method to override in subclasses that require control over tick locations.
The return value must be a list of three tuples:
[
(major tick spacing, offset),
(minor tick spacing, offset),
(sub-minor tick spacing, offset),
...
]
"""
dif = abs(maxVal - minVal)
if dif == 0:
return []
## decide optimal minor tick spacing in pixels (this is just aesthetics)
pixelSpacing = np.log(size+10) * 5
optimalTickCount = size / pixelSpacing
if optimalTickCount < 1:
optimalTickCount = 1
## optimal minor tick spacing
optimalSpacing = dif / optimalTickCount
## the largest power-of-10 spacing which is smaller than optimal
p10unit = 10 ** np.floor(np.log10(optimalSpacing))
## Determine major/minor tick spacings which flank the optimal spacing.
intervals = np.array([1., 2., 10., 20., 100.]) * p10unit
minorIndex = 0
while intervals[minorIndex+1] <= optimalSpacing:
minorIndex += 1
return [
(intervals[minorIndex+2], 0),
(intervals[minorIndex+1], 0),
(intervals[minorIndex], 0)
]
def tickValues(self, minVal, maxVal, size):
"""
Return the values and spacing of ticks to draw
[
(spacing, [major ticks]),
(spacing, [minor ticks]),
...
]
By default, this method calls tickSpacing to determine the correct tick locations.
This is a good method to override in subclasses.
"""
if self.logMode:
return self.logTickValues(minVal, maxVal, size)
ticks = []
tickLevels = self.tickSpacing(minVal, maxVal, size)
for i in range(len(tickLevels)):
spacing, offset = tickLevels[i]
## determine starting tick
start = (np.ceil((minVal-offset) / spacing) * spacing) + offset
## determine number of ticks
num = int((maxVal-start) / spacing) + 1
ticks.append((spacing, np.arange(num) * spacing + start))
return ticks
def logTickValues(self, minVal, maxVal, size):
v1 = int(np.floor(minVal))
v2 = int(np.ceil(maxVal))
major = range(v1+1, v2)
minor = []
for v in range(v1, v2):
minor.extend(v + np.log10(np.arange(1, 10)))
minor = filter(lambda x: x>minVal and x<maxVal, minor)
return [(1.0, major), (None, minor)]
def tickStrings(self, values, scale, spacing):
"""Return the strings that should be placed next to ticks. This method is called
when redrawing the axis and is a good method to override in subclasses.
The method is called with a list of tick values, a scaling factor (see below), and the
spacing between ticks (this is required since, in some instances, there may be only
one tick and thus no other way to determine the tick spacing)
The scale argument is used when the axis label is displaying units which may have an SI scaling prefix.
When determining the text to display, use value*scale to correctly account for this prefix.
For example, if the axis label's units are set to 'V', then a tick value of 0.001 might
be accompanied by a scale value of 1000. This indicates that the label is displaying 'mV', and
thus the tick should display 0.001 * 1000 = 1.
"""
if self.logMode:
return self.logTickStrings(values, scale, spacing)
places = max(0, np.ceil(-np.log10(spacing*scale)))
strings = []
for v in values:
vs = v * scale
if abs(vs) < .001 or abs(vs) >= 10000:
vstr = "%g" % vs
else:
vstr = ("%%0.%df" % places) % vs
strings.append(vstr)
return strings
def logTickStrings(self, values, scale, spacing):
return ["%0.1g"%x for x in 10 ** np.array(values).astype(float)]
def drawPicture(self, p):
p.setRenderHint(p.Antialiasing, False)
p.setRenderHint(p.TextAntialiasing, True)
prof = debug.Profiler("AxisItem.paint", disabled=True)
p.setPen(self.pen)
#bounds = self.boundingRect()
bounds = self.mapRectFromParent(self.geometry())
linkedView = self.linkedView()
if linkedView is None or self.grid is False:
tickBounds = bounds
else:
tickBounds = linkedView.mapRectToItem(self, linkedView.boundingRect())
if self.orientation == 'left':
span = (bounds.topRight(), bounds.bottomRight())
tickStart = tickBounds.right()
tickStop = bounds.right()
tickDir = -1
axis = 0
elif self.orientation == 'right':
span = (bounds.topLeft(), bounds.bottomLeft())
tickStart = tickBounds.left()
tickStop = bounds.left()
tickDir = 1
axis = 0
elif self.orientation == 'top':
span = (bounds.bottomLeft(), bounds.bottomRight())
tickStart = tickBounds.bottom()
tickStop = bounds.bottom()
tickDir = -1
axis = 1
elif self.orientation == 'bottom':
span = (bounds.topLeft(), bounds.topRight())
tickStart = tickBounds.top()
tickStop = bounds.top()
tickDir = 1
axis = 1
#print tickStart, tickStop, span
## draw long line along axis
p.drawLine(*span)
p.translate(0.5,0) ## resolves some damn pixel ambiguity
## determine size of this item in pixels
points = map(self.mapToDevice, span)
lengthInPixels = Point(points[1] - points[0]).length()
if lengthInPixels == 0:
return
tickLevels = self.tickValues(self.range[0], self.range[1], lengthInPixels)
textLevel = 1 ## draw text at this scale level
## determine mapping between tick values and local coordinates
dif = self.range[1] - self.range[0]
if axis == 0:
xScale = -bounds.height() / dif
offset = self.range[0] * xScale - bounds.height()
else:
xScale = bounds.width() / dif
offset = self.range[0] * xScale
prof.mark('init')
tickPositions = [] # remembers positions of previously drawn ticks
## draw ticks
## (to improve performance, we do not interleave line and text drawing, since this causes unnecessary pipeline switching)
## draw three different intervals, long ticks first
for i in range(len(tickLevels)):
tickPositions.append([])
ticks = tickLevels[i][1]
## length of tick
tickLength = self.tickLength / ((i*1.0)+1.0)
lineAlpha = 255 / (i+1)
if self.grid is not False:
lineAlpha = self.grid
for v in ticks:
x = (v * xScale) - offset
p1 = [x, x]
p2 = [x, x]
p1[axis] = tickStart
p2[axis] = tickStop
if self.grid is False:
p2[axis] += tickLength*tickDir
p.setPen(QtGui.QPen(QtGui.QColor(150, 150, 150, lineAlpha)))
p.drawLine(Point(p1), Point(p2))
tickPositions[i].append(x)
prof.mark('draw ticks')
## determine level to draw text
best = 0
for i in range(len(tickLevels)):
## take a small sample of strings and measure their rendered text
spacing, values = tickLevels[i]
strings = self.tickStrings(values[:2], self.scale, spacing)
if len(strings) == 0:
continue
textRects = [p.boundingRect(QtCore.QRectF(0, 0, 100, 100), QtCore.Qt.AlignCenter, s) for s in strings]
if axis == 0:
textSize = np.max([r.height() for r in textRects])
else:
textSize = np.max([r.width() for r in textRects])
## If these strings are not too crowded, then this level is ok
textFillRatio = float(textSize * len(values)) / lengthInPixels
if textFillRatio < 0.7:
best = i
continue
prof.mark('measure text')
spacing, values = tickLevels[best]
strings = self.tickStrings(values, self.scale, spacing)
for j in range(len(strings)):
vstr = strings[j]
x = tickPositions[best][j]
textRect = p.boundingRect(QtCore.QRectF(0, 0, 100, 100), QtCore.Qt.AlignCenter, vstr)
height = textRect.height()
self.textHeight = height
if self.orientation == 'left':
textFlags = QtCore.Qt.AlignRight|QtCore.Qt.AlignVCenter
rect = QtCore.QRectF(tickStop-100, x-(height/2), 99-max(0,self.tickLength), height)
elif self.orientation == 'right':
textFlags = QtCore.Qt.AlignLeft|QtCore.Qt.AlignVCenter
rect = QtCore.QRectF(tickStop+max(0,self.tickLength)+1, x-(height/2), 100-max(0,self.tickLength), height)
elif self.orientation == 'top':
textFlags = QtCore.Qt.AlignCenter|QtCore.Qt.AlignBottom
rect = QtCore.QRectF(x-100, tickStop-max(0,self.tickLength)-height, 200, height)
elif self.orientation == 'bottom':
textFlags = QtCore.Qt.AlignCenter|QtCore.Qt.AlignTop
rect = QtCore.QRectF(x-100, tickStop+max(0,self.tickLength), 200, height)
p.setPen(QtGui.QPen(QtGui.QColor(150, 150, 150)))
p.drawText(rect, textFlags, vstr)
prof.mark('draw text')
prof.finish()
def show(self):
if self.orientation in ['left', 'right']:
self.setWidth()
else:
self.setHeight()
GraphicsWidget.show(self)
def hide(self):
if self.orientation in ['left', 'right']:
self.setWidth(0)
else:
self.setHeight(0)
GraphicsWidget.hide(self)
def wheelEvent(self, ev):
if self.linkedView() is None:
return
if self.orientation in ['left', 'right']:
self.linkedView().wheelEvent(ev, axis=1)
else:
self.linkedView().wheelEvent(ev, axis=0)
ev.accept()
def mouseDragEvent(self, event):
if self.linkedView() is None:
return
if self.orientation in ['left', 'right']:
return self.linkedView().mouseDragEvent(event, axis=1)
else:
return self.linkedView().mouseDragEvent(event, axis=0)
def mouseClickEvent(self, event):
if self.linkedView() is None:
return
return self.linkedView().mouseClickEvent(event)