def make_edit(self, *args, placeholder, font_size, **kwargs):
ret = QLineEdit(*args, **kwargs)
ret.setPlaceholderText(placeholder)
@ret.textEdited.connect
def on_change(e):
self.recalculate()
if font_size:
font = ret.font()
font.setPointSize(font_size)
ret.setFont(font)
return ret
class Calculator(QWidget):
NumDigitButtons = 10
def __init__(self, parent=None):
super(Calculator, self).__init__(parent)
self.pendingAdditiveOperator = ''
self.pendingMultiplicativeOperator = ''
self.sumInMemory = 0.0
self.sumSoFar = 0.0
self.factorSoFar = 0.0
self.waitingForOperand = True
self.display = QLineEdit('0')
self.display.setReadOnly(True)
self.display.setAlignment(Qt.AlignRight)
self.display.setMaxLength(15)
font = self.display.font()
font.setPointSize(font.pointSize() + 8)
self.display.setFont(font)
self.digitButtons = []
for i in range(Calculator.NumDigitButtons):
self.digitButtons.append(
self.createButton(str(i), self.digitClicked))
self.pointButton = self.createButton(".", self.pointClicked)
self.changeSignButton = self.createButton(u"\N{PLUS-MINUS SIGN}",
self.changeSignClicked)
self.backspaceButton = self.createButton("Backspace",
self.backspaceClicked)
self.clearButton = self.createButton("C", self.clear)
self.clearAllButton = self.createButton("CE", self.clearAll)
self.clearMemoryButton = self.createButton("MC", self.clearMemory)
self.readMemoryButton = self.createButton("MR", self.readMemory)
self.setMemoryButton = self.createButton("MS", self.setMemory)
self.addToMemoryButton = self.createButton("M+", self.addToMemory)
self.divisionButton = self.createButton(
u"\N{DIVISION SIGN}", self.multiplicativeOperatorClicked)
self.timesButton = self.createButton(
u"\N{MULTIPLICATION SIGN}", self.multiplicativeOperatorClicked)
self.minusButton = self.createButton("-", self.additiveOperatorClicked)
self.plusButton = self.createButton("+", self.additiveOperatorClicked)
self.squareRootButton = self.createButton("Sqrt",
self.unaryOperatorClicked)
self.powerButton = self.createButton(u"x\N{SUPERSCRIPT TWO}",
self.unaryOperatorClicked)
self.reciprocalButton = self.createButton("1/x",
self.unaryOperatorClicked)
self.equalButton = self.createButton("=", self.equalClicked)
mainLayout = QGridLayout()
mainLayout.setSizeConstraint(QLayout.SetFixedSize)
mainLayout.addWidget(self.display, 0, 0, 1, 6)
mainLayout.addWidget(self.backspaceButton, 1, 0, 1, 2)
mainLayout.addWidget(self.clearButton, 1, 2, 1, 2)
mainLayout.addWidget(self.clearAllButton, 1, 4, 1, 2)
mainLayout.addWidget(self.clearMemoryButton, 2, 0)
mainLayout.addWidget(self.readMemoryButton, 3, 0)
mainLayout.addWidget(self.setMemoryButton, 4, 0)
mainLayout.addWidget(self.addToMemoryButton, 5, 0)
for i in range(1, Calculator.NumDigitButtons):
row = ((9 - i) / 3) + 2
column = ((i - 1) % 3) + 1
mainLayout.addWidget(self.digitButtons[i], row, column)
mainLayout.addWidget(self.digitButtons[0], 5, 1)
mainLayout.addWidget(self.pointButton, 5, 2)
mainLayout.addWidget(self.changeSignButton, 5, 3)
mainLayout.addWidget(self.divisionButton, 2, 4)
mainLayout.addWidget(self.timesButton, 3, 4)
mainLayout.addWidget(self.minusButton, 4, 4)
mainLayout.addWidget(self.plusButton, 5, 4)
mainLayout.addWidget(self.squareRootButton, 2, 5)
mainLayout.addWidget(self.powerButton, 3, 5)
mainLayout.addWidget(self.reciprocalButton, 4, 5)
mainLayout.addWidget(self.equalButton, 5, 5)
self.setLayout(mainLayout)
self.setWindowTitle("Calculator")
def digitClicked(self):
clickedButton = self.sender()
digitValue = int(clickedButton.text())
if self.display.text() == '0' and digitValue == 0.0:
return
if self.waitingForOperand:
self.display.clear()
self.waitingForOperand = False
self.display.setText(self.display.text() + str(digitValue))
def unaryOperatorClicked(self):
clickedButton = self.sender()
clickedOperator = clickedButton.text()
operand = float(self.display.text())
if clickedOperator == "Sqrt":
if operand < 0.0:
self.abortOperation()
return
result = math.sqrt(operand)
elif clickedOperator == u"x\N{SUPERSCRIPT TWO}":
result = math.pow(operand, 2.0)
elif clickedOperator == "1/x":
if operand == 0.0:
self.abortOperation()
return
result = 1.0 / operand
self.display.setText(str(result))
self.waitingForOperand = True
def additiveOperatorClicked(self):
clickedButton = self.sender()
clickedOperator = clickedButton.text()
operand = float(self.display.text())
if self.pendingMultiplicativeOperator:
if not self.calculate(operand, self.pendingMultiplicativeOperator):
self.abortOperation()
return
self.display.setText(str(self.factorSoFar))
operand = self.factorSoFar
self.factorSoFar = 0.0
self.pendingMultiplicativeOperator = ''
if self.pendingAdditiveOperator:
if not self.calculate(operand, self.pendingAdditiveOperator):
self.abortOperation()
return
self.display.setText(str(self.sumSoFar))
else:
self.sumSoFar = operand
self.pendingAdditiveOperator = clickedOperator
self.waitingForOperand = True
def multiplicativeOperatorClicked(self):
clickedButton = self.sender()
clickedOperator = clickedButton.text()
operand = float(self.display.text())
if self.pendingMultiplicativeOperator:
if not self.calculate(operand, self.pendingMultiplicativeOperator):
self.abortOperation()
return
self.display.setText(str(self.factorSoFar))
else:
self.factorSoFar = operand
self.pendingMultiplicativeOperator = clickedOperator
self.waitingForOperand = True
def equalClicked(self):
operand = float(self.display.text())
if self.pendingMultiplicativeOperator:
if not self.calculate(operand, self.pendingMultiplicativeOperator):
self.abortOperation()
return
operand = self.factorSoFar
self.factorSoFar = 0.0
self.pendingMultiplicativeOperator = ''
if self.pendingAdditiveOperator:
if not self.calculate(operand, self.pendingAdditiveOperator):
self.abortOperation()
return
self.pendingAdditiveOperator = ''
else:
self.sumSoFar = operand
self.display.setText(str(self.sumSoFar))
self.sumSoFar = 0.0
self.waitingForOperand = True
def pointClicked(self):
if self.waitingForOperand:
self.display.setText('0')
if "." not in self.display.text():
self.display.setText(self.display.text() + ".")
self.waitingForOperand = False
def changeSignClicked(self):
text = self.display.text()
value = float(text)
if value > 0.0:
text = "-" + text
elif value < 0.0:
text = text[1:]
self.display.setText(text)
def backspaceClicked(self):
if self.waitingForOperand:
return
text = self.display.text()[:-1]
if not text:
text = '0'
self.waitingForOperand = True
self.display.setText(text)
def clear(self):
if self.waitingForOperand:
return
self.display.setText('0')
self.waitingForOperand = True
def clearAll(self):
self.sumSoFar = 0.0
self.factorSoFar = 0.0
self.pendingAdditiveOperator = ''
self.pendingMultiplicativeOperator = ''
self.display.setText('0')
self.waitingForOperand = True
def clearMemory(self):
self.sumInMemory = 0.0
def readMemory(self):
self.display.setText(str(self.sumInMemory))
self.waitingForOperand = True
def setMemory(self):
self.equalClicked()
self.sumInMemory = float(self.display.text())
def addToMemory(self):
self.equalClicked()
self.sumInMemory += float(self.display.text())
def createButton(self, text, member):
button = Button(text)
button.clicked.connect(member)
return button
def abortOperation(self):
self.clearAll()
self.display.setText("####")
def calculate(self, rightOperand, pendingOperator):
if pendingOperator == "+":
self.sumSoFar += rightOperand
elif pendingOperator == "-":
self.sumSoFar -= rightOperand
elif pendingOperator == u"\N{MULTIPLICATION SIGN}":
self.factorSoFar *= rightOperand
elif pendingOperator == u"\N{DIVISION SIGN}":
if rightOperand == 0.0:
return False
self.factorSoFar /= rightOperand
return True
