An-Najah Staff

#!/usr/bin/env python
# Copyright (c) 2007-8 Qtrac Ltd. All rights reserved.
# This program or module is free software: you can redistribute it and/or
# modify it under the terms of the GNU General Public License as published
# by the Free Software Foundation, either version 2 of the License, or
# version 3 of the License, or (at your option) any later version. It is
# provided for educational purposes and is distributed in the hope that
# it will be useful, but WITHOUT ANY WARRANTY; without even the implied
# warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
# the GNU General Public License for more details.

import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *

class Form(QDialog):

    def __init__(self, parent=None):
        super(Form, self).__init__(parent)

        dial = QDial()
        dial.setNotchesVisible(True)
        spinbox = QSpinBox()

        layout = QHBoxLayout()
        layout.addWidget(dial)
        layout.addWidget(spinbox)
        self.setLayout(layout)

        self.connect(dial, SIGNAL("valueChanged(int)"),
                     spinbox.setValue)
        self.connect(spinbox, SIGNAL("valueChanged(int)"),
                     dial.setValue)
        self.setWindowTitle("Signals and Slots")


class Form2(QDialog):

    def __init__(self, parent=None):
        super(Form2, self).__init__(parent)

        dial = QDial()
        dial.setNotchesVisible(True)
        spinbox = QSpinBox()

        layout = QHBoxLayout()
        layout.addWidget(dial)
        layout.addWidget(spinbox)
        self.setLayout(layout)

        self.connect(dial, SIGNAL("valueChanged(int)"),
                     spinbox, SLOT("setValue(int)"))
        self.connect(spinbox, SIGNAL("valueChanged(int)"),
                     dial, SLOT("setValue(int)"))
        self.setWindowTitle("Signals and Slots")


class ZeroSpinBox(QSpinBox):

    zeros = 0

    def __init__(self, parent=None):
        super(ZeroSpinBox, self).__init__(parent)
        self.connect(self, SIGNAL("valueChanged(int)"), self.checkzero)


    def checkzero(self):
        if self.value() == 0:
            self.zeros += 1
            self.emit(SIGNAL("atzero"), self.zeros)


class Form3(QDialog):

    def __init__(self, parent=None):
        super(Form3, self).__init__(parent)

        dial = QDial()
        dial.setNotchesVisible(True)
        zerospinbox = ZeroSpinBox()

        layout = QHBoxLayout()
        layout.addWidget(dial)
        layout.addWidget(zerospinbox)
        self.setLayout(layout)

        self.connect(dial, SIGNAL("valueChanged(int)"),
                     zerospinbox, SLOT("setValue(int)"))
        self.connect(zerospinbox, SIGNAL("valueChanged(int)"),
                     dial, SLOT("setValue(int)"))
        self.connect(zerospinbox, SIGNAL("atzero"), self.announce)
        self.setWindowTitle("Signals and Slots")


    def announce(self, zeros):
        print "ZeroSpinBox has been at zero %d times" % zeros


class Form4(QDialog):

    def __init__(self, parent=None):
        super(Form4, self).__init__(parent)

        lineedit = QLineEdit()

        layout = QHBoxLayout()
        layout.addWidget(lineedit)
        self.setLayout(layout)

        self.connect(lineedit, SIGNAL("textChanged(QString)"),
                     self.consoleEcho)
        self.setWindowTitle("Signals and Slots")


    def consoleEcho(self, text):
        print unicode(text)
        


class TaxRate(QObject):

    def __init__(self):
        super(TaxRate, self).__init__()
        self.__rate = 17.5


    def rate(self):
        return self.__rate


    def setRate(self, rate):
        if rate != self.__rate:
            self.__rate = rate
            self.emit(SIGNAL("rateChanged"), self.__rate)


def rateChanged(value):
    print "TaxRate changed to %.2f%%" % value


app = QApplication(sys.argv)
form = None

##if len(sys.argv) == 1 or sys.argv[1] == "1":
##    form = Form4()
##elif sys.argv[1] == "2":
##    form = Form2()
##elif sys.argv[1] == "3":
##    form = Form3()
##elif sys.argv[1] == "4":
##    form = Form4()
##if form is not None:
##    form.show()
##    app.exec_()
##else: # if sys.argv[1] == "5"
vat = TaxRate()
vat.connect(vat, SIGNAL("rateChanged"), rateChanged)
vat.setRate(17.5)    # No change will occur (new rate is the same)
vat.setRate(8.5)     # A change will occur (new rate is different)