qt hiding a control on showEvent()

I call show() on a window and it has several controls and all controls are displayed.

One of the controls is a custom control that inherits from QFrame.

I want to hide this control if a particular flag is set. So, I have

void MyCustomControl::showEvent ( QShowEvent * /* evt */ )
{
    if (!m_visibleAllowed)
        hide();
} 

While this hides the control, it makes the control goofy; it looks frozen. When the window is r开发者_StackOverflowesized, the area where the control is supposed to be does not get refreshed. Searching around forums, the idea that I get is that hiding the control is not supposed to be done on showEvent() is that true? if so then how/where should I try to hide the control. If hiding the control from showEvent() is possible, how can I prevent the control getting frozen.

Thanks for you time.

---

If the problem is with calling hide() during your show event (I can't confirm that it's explicitly disallowed, but it doesn't sound like a good idea in general) and calling hide from your show event is where you really need to have this code then you could use a single shot timer:

QTimer::singleShot( 0, this, SLOT(hide()) );

which will simply defer the execution of the hide() function until the next round of the event loop.

---

Maybe you could use a QStackedLayout or a QStackedWidget that has two widgets in the stack: your control, and a "blank" QWidget. If you did that, instead of using show() and hide() on your control, you switch what's on top of the stack.

That way you never try to render a hidden widget - if your control isn't visible, you render the blank QWidget instead - and I suspect this will solve your graphics glitches.

Hope this helps!