How to connect custom signal to slot in pyside with the new syntax?

Question

This is an example from an video tutorial:

#!/usr/bin/env python3

import sys
from PySide.QtCore import *
from PySide.QtGui import *

class ZeroSpinBox(QSpin         


        

Answer 1

Your have to declare new signal in class your implemented or inheritance;

class ZeroSpinBox (QSpinBox):
    atzero = Signal(int)
    .
    .

Then, your can call it in new-style signal. For emit signal;

        self.emit(SIGNAL("atzero(int)"), self.zeros)

Change to

        self.atzero.emit(self.zeros)

For connect signal;

         self.connect(zerospinbox, SIGNAL("atzero(int)"), self.announce)

Change to

         zerospinbox.atzero.connect(self.announce)

Also you can read this document to more information.

---

Implement code example (PyQt4 also same PySide, different is name Signal & pyqtSignal);

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

class ZeroSpinBox(QSpinBox):
    atzero = pyqtSignal(int)

    zeros = 0

    def __init__(self):
        super(ZeroSpinBox, self).__init__()
        self.valueChanged.connect(self.checkzero)

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



class Form(QDialog):

    def __init__(self):
        super(Form, self).__init__()

        dial = QDial()
        dial.setNotchesVisible(True)
        zerospinbox = ZeroSpinBox()
        layout = QHBoxLayout()
        layout.addWidget(dial)
        layout.addWidget(zerospinbox)
        self.setLayout(layout)

        dial.valueChanged.connect(zerospinbox.setValue)
        zerospinbox.valueChanged.connect(dial.setValue)
        zerospinbox.atzero.connect(self.announce)
#         self.connect(zerospinbox, SIGNAL("atzero(int)"), self.announce)

        self.setWindowTitle("Signals")

    def announce(self, zeros):
        print("zerospinbox has been at zero " + str(zeros) + " times.")



app = QApplication(sys.argv)
form = Form()
form.show()
app.exec_()