def showStack(self, index):
        if (index >= self.getWidgetCount()) or (index == self.visibleStack):
            return

        if self.visibleStack >= 0:
            self.setStackVisible(self.visibleStack, False)

        self.visibleStack = index
        self.setStackVisible(self.visibleStack, True)
        for listener in self.stackListeners:
            listener.onStackChanged(self, index)
dataset/ETHPy150Open anandology/pyjamas/library/gwt/ui/StackPanel.py/StackPanel.showStack/original