Check if a subview is in a view

I'm making an app where I add a subview to a view using addSubview: on an IBAction. In the same way, when the button with that IBAction is touched again should call removeFromSuperview on that subview added on that IBAction:

PSEUDO CODE

-(IBAction)showPopup:(id)sender 
{
    System_monitorAppDelegate *delegate = (System_monitorAppDelegate *)[[UIApplication sharedApplication] delegate];
    UIView *rootView = delegate.window.rootViewController.view;

    if([self popoverView] is not on rootView) 
    { 
	    [rootView addSubview:[self popoverView]];
    } 
    else 
    {
	    [[self popoverView] removeFromSuperview];
    }

}

You are probably looking for UIView's -(BOOL)isDescendantOfView:(UIView *)view; taken in UIView class reference.

> Return Value > YES if the receiver is an immediate or distant > subview of view or if view is the receiver itself; otherwise NO.

You will end up with a code like :

###Objective-C

- (IBAction)showPopup:(id)sender {
    if(![self.myView isDescendantOfView:self.view]) { 
        [self.view addSubview:self.myView];
    } else {
        [self.myView removeFromSuperview];
    }
}

###Swift 3

@IBAction func showPopup(sender: AnyObject) {
    if !self.myView.isDescendant(of: self.view) {
        self.view.addSubview(self.myView)
    } else {
        self.myView.removeFromSuperview()
    }
}

Try this:

-(IBAction)showPopup:(id)sender
{
    if (!myView.superview)
        [self.view addSubview:myView];
    else
        [myView removeFromSuperview];
}

    UIView *subview = ...;
    if([self.view.subviews containsObject:subview]) {
        ...
    }

The Swift equivalent will look something like this:

if(!myView.isDescendantOfView(self.view)) {
	self.view.addSubview(myView)
} else {
	myView.removeFromSuperview()
}

Check the superview of the subview...

-(IBAction)showPopup:(id)sender {
    if([[self myView] superview] == self.view) { 
        [[self myView] removeFromSuperview];           
    } else {
        [self.view addSubview:[self myView]];         
    }
}

Your if condition should go like

if (!([rootView subviews] containsObject:[self popoverView])) { 
    [rootView addSubview:[self popoverView]];
} else {
    [[self popoverView] removeFromSuperview];
    
}

Here we used two different views. Parent view is the view in which we are searching for descendant view and check wether added to parent view or not.

if parentView.subviews.contains(descendantView) {
   // descendant view added to the parent view.
}else{
  // descendant view not added to the parent view.
}