Connecting/disconnecting signals via eventFilter - qt

Question

I have an app with hundreds of custom buttons, each one needs multiple signal connections. The connect calls seem to be pretty slow, so I'm trying to connect/disconnect each button's signals via the main window's eventFilter using the enter and leave events.
However, sometimes those events seems to be called multiple times, causing RuntimeErrors (when trying to disconnect an event that is already gone).
Here is a snippet of code that shows a similar (and hopefully related) problem using default PushButtons.
To see the runtime error here, run the code, push one of the buttons, then close the window. That's when I see this:
RuntimeError: Fail to disconnect signal clicked().
Here is the code. Does anybody know if this is a PySide bug?
from PySide.QtGui import *
from PySide.QtCore import *
import sys
class TestWindow( QWidget ):
def __init__( self, parent=None ):
super( TestWindow, self ).__init__( parent )
self.setLayout( QGridLayout() )
def addWidget( self, w ):
self.layout().addWidget( w )
def testCB( self ):
print 'button connected'
def eventFilter( self, obj, event ):
'''Connect signals on mouse over'''
if event.type() == QEvent.Enter:
print 'enter',
obj.clicked.connect( self.testCB )
elif event.type() == QEvent.Leave:
print 'leave'
obj.clicked.disconnect( self.testCB )
return False
app = QApplication( sys.argv )
w = TestWindow()
for i in xrange(10):
btn = QPushButton( 'test %s' % i )
w.addWidget( btn )
btn.installEventFilter(w)
w.show()
sys.exit( app.exec_() )

Answer 1

In few cases, when I tested mouse events, showed better performance while events are attached to item class... so don't subclass. Rather :
class Button(QPushButton):
def __init__(self, label):
super(Button, self).__init__()
self.setText(label)
app = QApplication( sys.argv )
w = TestWindow()
for i in xrange(10):
btn = Button( 'test %s' % i )
w.addWidget( btn )
...then define mouse event for class.