iPhone: detecting if a UIAlert/UIActionSheet are open

Question

In my iOS application, I have a timer firing up, and when it fires, I need to be able to detect whether there's an Alert (UIAlertView) or an Action Sheet (UIActionSheet) open.

One way would be to modify the code presenting the alerts/actionsheets - but unfortunately this is not an option in my case.

So, the question is - is there a way of knowing/detecting whether an alert or action sheet have been opened?

Is there any notifications sent upon opening, or any traversal of the view hierarchy to detect it?

Thanks

Solution 1

They do send an alert when they open, but only to their delegate -- Check this question for a nice approach to that problem. Techzen recommends setting a boolean flag to YES when you open up the alert, and setting it back to NO when you dismiss the alert.

EDIT:

Since you don't have access at all to the code, why not try this clunky piece of code:

-(BOOL) doesAlertViewExist {
  for (UIWindow* window in [UIApplication sharedApplication].windows) {
    NSArray* subviews = window.subviews;
    if ([subviews count] > 0) {

      BOOL alert = [[subviews objectAtIndex:0] isKindOfClass:[UIAlertView class]];
      BOOL action = [[subviews objectAtIndex:0] isKindOfClass:[UIActionSheet class]];

      if (alert || action)
        return YES;
     }
  }
  return NO;
}

Solution 2

- (BOOL) doesAlertViewExist {
    for (UIWindow* window in [UIApplication sharedApplication].windows) {
        for (UIView* view in window.subviews) {
            BOOL alert = [view isKindOfClass:[UIAlertView class]];
            BOOL action = [view isKindOfClass:[UIActionSheet class]];
            if (alert || action)
                return YES;
        }
    }
    return NO;
}

Solution 3

You can also check for the view's window property:

if(actionSheet.window)
    isBeingPresented = YES;

Solution 4

Detecting alerts seems relatively easy, but action sheets had me stumped. In iOS 6.1 I had to go one step further

BOOL IsActionOpen(UIView* aView) {
BOOL    actionOpen = NO;
if (aView) {
    if ([aView isKindOfClass:[UIActionSheet class]]) {
        actionOpen = YES;
    }
    else if (aView.subviews.count > 0) {
        for (UIView* aSubview in aView.subviews) {
            if ( IsActionOpen( aSubview)) {
                actionOpen = YES;
                break;
            }
        }
    }
}
return actionOpen;

}

- (BOOL) isAnActionSheetOpen {
BOOL    actionOpen = NO;
for (UIWindow* w in [UIApplication sharedApplication].windows) {
    actionOpen =  IsActionOpen(w);
    if (actionOpen)
        break;
}
return actionOpen;

}

Solution 5

thanx for the help, but since iOS 6, the code piece doesn't work anymore. However, I fixed the issue with this code. Hope this helps

for (UIWindow* window in [UIApplication sharedApplication].windows) {
    NSArray* subviews = window.subviews;
    if ([subviews count] > 1) {
        BOOL alert = [[subviews objectAtIndex:1] isKindOfClass:[UIAlertView class]];
        BOOL action = [[subviews objectAtIndex:1] isKindOfClass:[UIActionSheet class]];

        if (alert || action)
            return YES;
    }
}
return NO;

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Comments

[Reuven]

THANKS! I had to apply two changes to the proposal: (1) subviews in an NSArray* and not UIView*. (2) Seems like the UIActionSheet is not the first [0] subview, but the second [1]. So I iterated the view hierarchy... Code is posted as answer...

[Keith at Ideal Films]

I used TechZen's other suggestion of retaining a reference. I found this worked very elegantly.

[user968597]

hello i am also facing same problem i tried with the above code however when i try to print the array of "window.subviews" , not getting any object of uiactionsheet .Before this i kept open one actionsheet .what can be the problem please give some solution on this

[Reuven]

I've only used this code on an iPhone - can it be you're using it on an iPad?

[Tarun]

Not Working at all on ipad. :(

[Jeff Mascia]

In iOS 7 this code works for action sheets, but it no longer works for alert views. Seems like the best solution for alert views is to keep track of them... stackoverflow.com/q/18702565/268153