title: How to override isclick() sigal in Pyqt?
body: <p>I have a class BooleanButton contains extra boolean flag to toggle every click. After each click, I want it to emit a signal and the slot will receive the boolean flag. I just write the following, but of course, it won't work.</p>
  
  <pre><code>class BooleanButton(QPushButton):
      def __init__(self, name):
          QPushButton.__init__(self, name)
          self.bool = False
  
      def clicked(self, bool):
          self.bool = not self.bool
          self.emit(self.bool)
  </code></pre>
  
  <p>After creating the object, it connects to a slot. When I click this button, a swapping true-false signal will send to the slot.</p>
  
  <pre><code>bool_btn.isclicked[bool].connect(widget.func)
  </code></pre>
  
  <p>Thanks.</p>