[SOLVED] How to find out whether child widget of QScroll Area is visible?

jesuisbenjamin

Hello,

I am displaying multiple QLabels on a QFrame, placed into a QScrollArea. I am able to tell QScrollArea to make any of the QLabels visible with QScrollArea.ensureVisible(QLabel), but I cannot seem to find a method to find out whether the child widget is currently visible or not. I would expect something like QScrollArea.isWidgetVisible(QWidget). I tried using the child's own method, i.e. QLabel.isVisible() but no matter whether the QLabel is visible or not in the QScrollArea, it always returns True. What's the solution?

jesuisbenjamin

I got an answer from "StackOverflow":http://stackoverflow.com/questions/10631067/how-to-find-out-whether-child-widget-of-qscrollarea-is-visible:

I proposed the following code:
@
#!/usr/bin/env python

import sys
from PyQt4 import QtGui, QtCore

application = QtGui.QApplication(sys.argv)

class Area(QtGui.QScrollArea):

def __init__(self, child):
        super(Area, self).__init__()
    self.child = child
    self.setWidget(self.child)
    self.setFixedSize(100, 100)

class MainWidget(QtGui.QFrame):

def __init__(self, parent=None):
        QtGui.QFrame.__init__(self, parent)
    self.layout = QtGui.QVBoxLayout()
    n = 1
    while n != 10:
        label = QtGui.QLabel('<h1>'+str(n)+'</h1>')
        self.layout.addWidget(label)
        n += 1
    self.setLayout(self.layout)

def wheelEvent(self, event):
    print "Wheel Event:"
    for child in self.children()[1:]:
        print child.isVisible()
    event.ignore()

mainwidget = MainWidget()
area = Area(mainwidget)
area.show()
application.exec_()
@

And it was suggested I change the wheelEvent() method as such:

@
def wheelEvent(self, event):
print "Wheel Event:"
for child in self.children()[1:]:
print child.text(), 'is visible?', not child.visibleRegion().isEmpty()
event.ignore()
@

And that does the job! :)