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artiq/artiq/gui/scientific_spinbox.py

72 lines
2.0 KiB
Python

import re
from PyQt5 import QtGui, QtWidgets
# after
# http://jdreaver.com/posts/2014-07-28-scientific-notation-spin-box-pyside.html
_inf = float("inf")
# Regular expression to find floats. Match groups are the whole string, the
# whole coefficient, the decimal part of the coefficient, and the exponent
# part.
_float_re = re.compile(r"(([+-]?\d+(\.\d*)?|\.\d+)([eE][+-]?\d+)?)")
def valid_float_string(string):
match = _float_re.search(string)
if match:
return match.groups()[0] == string
return False
class FloatValidator(QtGui.QValidator):
def validate(self, string, position):
if valid_float_string(string):
return self.Acceptable, string, position
if string == "" or string[position-1] in "eE.-+":
return self.Intermediate, string, position
return self.Invalid, string, position
def fixup(self, text):
match = _float_re.search(text)
if match:
return match.groups()[0]
return ""
class ScientificSpinBox(QtWidgets.QDoubleSpinBox):
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.setMinimum(-_inf)
self.setMaximum(_inf)
self.validator = FloatValidator()
self.setDecimals(20)
def validate(self, text, position):
return self.validator.validate(text, position)
def fixup(self, text):
return self.validator.fixup(text)
def valueFromText(self, text):
return float(text)
def textFromValue(self, value):
return format_float(value)
def stepBy(self, steps):
text = self.cleanText()
groups = _float_re.search(text).groups()
decimal = float(groups[1])
decimal += steps
new_string = "{:g}".format(decimal) + (groups[3] if groups[3] else "")
self.lineEdit().setText(new_string)
def format_float(value):
"""Modified form of the 'g' format specifier."""
string = "{:g}".format(value)
string = string.replace("e+", "e")
string = re.sub("e(-?)0*(\d+)", r"e\1\2", string)
return string