Source code for pyqtgraph.graphicsItems.GradientLegend

from .. import functions as fn
from ..Qt import QtCore, QtGui
from .UIGraphicsItem import UIGraphicsItem

__all__ = ['GradientLegend']

[docs] class GradientLegend(UIGraphicsItem): """ Draws a color gradient rectangle along with text labels denoting the value at specific points along the gradient. """
[docs] def __init__(self, size, offset): self.size = size self.offset = offset UIGraphicsItem.__init__(self) self.setAcceptedMouseButtons(QtCore.Qt.MouseButton.NoButton) self.brush = QtGui.QBrush(QtGui.QColor(255,255,255,100)) # background color self.pen = QtGui.QPen(QtGui.QColor(0,0,0)) self.textPen = QtGui.QPen(QtGui.QColor(0,0,0)) self.labels = {'max': 1, 'min': 0} self.gradient = QtGui.QLinearGradient() self.gradient.setColorAt(0, QtGui.QColor(0,0,0)) self.gradient.setColorAt(1, QtGui.QColor(255,0,0)) self.setZValue(100) # draw on top of ordinary plots
def setGradient(self, g): self.gradient = g self.update()
[docs] def setColorMap(self, colormap): """ Set displayed gradient from a :class:`~pyqtgraph.ColorMap` object. """ self.gradient = colormap.getGradient()
def setIntColorScale(self, minVal, maxVal, *args, **kargs): colors = [fn.intColor(i, maxVal-minVal, *args, **kargs) for i in range(minVal, maxVal)] g = QtGui.QLinearGradient() for i in range(len(colors)): x = float(i)/len(colors) g.setColorAt(x, colors[i]) self.setGradient(g) if 'labels' not in kargs: self.setLabels({str(minVal): 0, str(maxVal): 1}) else: self.setLabels({kargs['labels'][0]:0, kargs['labels'][1]:1})
[docs] def setLabels(self, l): """Defines labels to appear next to the color scale. Accepts a dict of {text: value} pairs""" self.labels = l self.update()
def paint(self, p, opt, widget): UIGraphicsItem.paint(self, p, opt, widget) view = self.getViewBox() if view is None: return p.save() # save painter state before we change transformation trans = view.sceneTransform() p.setTransform( trans ) # draw in ViewBox pixel coordinates rect = view.rect() ## determine max width of all labels labelWidth = 0 labelHeight = 0 for k in self.labels: b = p.boundingRect(QtCore.QRectF(0, 0, 0, 0), QtCore.Qt.AlignmentFlag.AlignLeft | QtCore.Qt.AlignmentFlag.AlignVCenter, str(k)) labelWidth = max(labelWidth, b.width()) labelHeight = max(labelHeight, b.height()) textPadding = 2 # in px xR = rect.right() xL = rect.left() yT = rect.top() yB = rect.bottom() # coordinates describe edges of text and bar, additional margins will be added for background if self.offset[0] < 0: x3 = xR + self.offset[0] # right edge from right edge of view, offset is negative! x2 = x3 - labelWidth - 2*textPadding # right side of color bar x1 = x2 - self.size[0] # left side of color bar else: x1 = xL + self.offset[0] # left edge from left edge of view x2 = x1 + self.size[0] x3 = x2 + labelWidth + 2*textPadding # leave room for 2x textpadding between bar and text if self.offset[1] < 0: y2 = yB + self.offset[1] # bottom edge from bottom of view, offset is negative! y1 = y2 - self.size[1] else: y1 = yT + self.offset[1] # top edge from top of view y2 = y1 + self.size[1] self.b = [x1,x2,x3,y1,y2,labelWidth] ## Draw background p.setPen(self.pen) p.setBrush(self.brush) # background color rect = QtCore.QRectF( QtCore.QPointF(x1 - textPadding, y1-labelHeight/2 - textPadding), # extra left/top padding QtCore.QPointF(x3 + textPadding, y2+labelHeight/2 + textPadding) # extra bottom/right padding ) p.drawRect(rect) ## Draw color bar self.gradient.setStart(0, y2) self.gradient.setFinalStop(0, y1) p.setBrush(self.gradient) rect = QtCore.QRectF( QtCore.QPointF(x1, y1), QtCore.QPointF(x2, y2) ) p.drawRect(rect) ## draw labels p.setPen(self.textPen) tx = x2 + 2 * textPadding # margin between bar and text lh = labelHeight lw = labelWidth for k in self.labels: y = y2 - self.labels[k] * (y2-y1) p.drawText(QtCore.QRectF(tx, y - lh/2, lw, lh), QtCore.Qt.AlignmentFlag.AlignLeft | QtCore.Qt.AlignmentFlag.AlignVCenter, str(k)) p.restore() # restore QPainter transform to original state