I implement this feature like the following ,but when you move the scroll bars to the top or bottom by mouse wheel ,an error would occur : maximum recursion depth exceeded while calling a Python object.
anyone can help ?
@
import sys
from PyQt4.QtGui import *
from PyQt4.QtCore import *
class BoxLayout(QWidget):
def init(self, parent=None):
super(BoxLayout, self).init(parent)
self.resize(100, 300)

    ok = QPushButton("OK")
    cancel = QPushButton("Cancel")
    self.textEdit = QTextEdit("""This function returns true if the contents of the MIME data object, specified by source , can be decoded and inserted into the document. It is called for example when during a drag operation the mouse enters this widget and it is necessary to determine whether it is possible to accept the drag and drop operation.""")
    
    vbox = QVBoxLayout()
    vbox.addWidget(self.textEdit)
    vbox.addWidget(ok)
    vbox.addWidget(cancel)
    self.setLayout(vbox)

self.textEdit.installEventFilter(self)

def eventFilter(self, obj, event):

if obj == self.textEdit:

if event.type() == QEvent.Wheel:

self.textEdit.wheelEvent(event)

return True

else:

return False

else:

return QMainWindow.eventFilter(self, obj, event)

def wheelEvent(self, event):
    self.textEdit.wheelEvent(event)

app = QApplication(sys.argv)
qb = BoxLayout()
qb.show()
sys.exit(app.exec_())
@