How to get UIView hierarchy index? (i.e. the depth

Question

From UIView docs:

(void)insertSubview:(UIView *)view atIndex:(NSInteger)index

It's great that I can insert a UIView at a certain index, but I cannot find a way to READ what index a given UIView has.

I need to check whether the UIView is on top, or at the back ...

EDIT: Now that Brandon pointed out the order in the subviews array, I put together a UIView Category free for download providing few handy methods to handle the subviews hierarchy here: http://www.touch-code-magazine.com/uiview-layout-hierarchy-uiview-category-to-download/

Answer 1

I am almost 100% sure that the index is the same as the index of the subView inside the superViews subviews property.

UIView * superView = .... some view
UIView * subView = .... some other view
[superView insertSubview:subView atIndex:index];
int viewIndex = [[superView subviews] indexOfObject:subView];
// viewIndex and index should be the same

I just tested this with the following code and it works

UIView* view1 = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 50, 50)];
UIView* view2 = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 50, 50)];
UIView* view3 = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 50, 50)];
[self.view insertSubview:view1 atIndex:1];
[self.view insertSubview:view2 atIndex:2];
[self.view insertSubview:view3 atIndex:3];

NSLog(@"%d", [[self.view subviews] indexOfObject:view1]); // Is 1
NSLog(@"%d", [[self.view subviews] indexOfObject:view2]); // Is 2
NSLog(@"%d", [[self.view subviews] indexOfObject:view3]); // Is 3

[self.view bringSubviewToFront:view1];
NSLog(@"%d", [[self.view subviews] indexOfObject:view1]); // Is end of array

[self.view sendSubviewToBack:view1];
NSLog(@"%d", [[self.view subviews] indexOfObject:view1]); // Is 0

Answer 2

Set up a recursive method as follows:

- (void)printViewHierarchy:(UIView *)viewNode depth:(NSUInteger)depth
{
    for (UIView *v in viewNode.subviews)
    {
        NSLog(@"%@%@", [@"" stringByPaddingToLength:depth withString:@"|-" startingAtIndex:0], [v description]);
        if ([v.subviews count])
            [self printViewHierarchy:v depth:(depth + 2)]; // + 2 to make the output look correct with the stringPadding
    }
}

Then call it with:

[self printViewHierarchy:self.view depth:0];

Output:

[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: <UILayoutContainerView: 0x622ce70; frame = (0 0; 768 1004); autoresize = W+H; layer = <CALayer: 0x622cec0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-<UINavigationTransitionView: 0x622cfa0; frame = (0 0; 768 1004); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x622cff0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-<UIViewControllerWrapperView: 0x601c4c0; frame = (0 0; 768 1004); autoresize = RM+BM; layer = <CALayer: 0x607c5f0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-<UIView: 0x6069c40; frame = (0 0; 768 1004); opaque = NO; autoresize = RM+BM; layer = <CALayer: 0x607b460>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-<UIToolbar: 0x623a550; frame = (0 0; 768 44); opaque = NO; autoresize = W+BM; layer = <CALayer: 0x623a610>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-<UIToolbarTextButton: 0x626d6a0; frame = (7 0; 52 44); opaque = NO; layer = <CALayer: 0x626e200>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIPushButton: 0x626d920; frame = (0 7; 52 30); opaque = NO; layer = <CALayer: 0x626d9c0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-<UIView: 0x623a440; frame = (69 -1; 755 45); opaque = NO; autoresize = W+BM; layer = <CALayer: 0x623a470>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIButton: 0x621cec0; frame = (-185 0; 505 45); opaque = NO; autoresize = W+BM; layer = <CALayer: 0x621cc20>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x62206d0; frame = (-35 -28; 100 100); alpha = 0; opaque = NO; userInteractionEnabled = NO; tag = 1886548836; layer = <CALayer: 0x621cc50>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x607ec40; frame = (0 7; 30 30); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x607ec70>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIButtonLabel: 0x62306c0; frame = (32 14; 38 16); text = 'About'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x6230780>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIButton: 0x6230a00; frame = (-109 0; 510 45); opaque = NO; autoresize = W+BM; layer = <CALayer: 0x6230660>>

[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x6230a90; frame = (-35 -28; 100 100); alpha = 0; opaque = NO; userInteractionEnabled = NO; tag = 1886548836; layer = <CALayer: 0x6230ac0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x607ebc0; frame = (0 7; 30 30); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x607ebf0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIButtonLabel: 0x6231620; frame = (35 14; 30 16); text = 'Staff'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x6231e20>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIButton: 0x6231ea0; frame = (13 0; 465 45); opaque = NO; autoresize = W+BM; layer = <CALayer: 0x6231e50>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x6231f30; frame = (-35 -28; 100 100); alpha = 0; opaque = NO; userInteractionEnabled = NO; tag = 1886548836; layer = <CALayer: 0x6231f60>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x607eb40; frame = (0 7; 30 30); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x607eb70>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIButtonLabel: 0x6233430; frame = (35 14; 71 16); text = 'Procedures'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x62334a0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIButton: 0x6233520; frame = (110 0; 485 45); opaque = NO; autoresize = W+BM; layer = <CALayer: 0x62334d0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x62335b0; frame = (-35 -28; 100 100); alpha = 0; opaque = NO; userInteractionEnabled = NO; tag = 1886548836; layer = <CALayer: 0x62335e0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x607eac0; frame = (0 7; 30 30); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x607eaf0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIButtonLabel: 0x6234190; frame = (35 14; 52 16); text = 'Specials'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x62349d0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIButton: 0x6237560; frame = (200 0; 490 45); opaque = NO; autoresize = W+BM; layer = <CALayer: 0x6237510>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x62375f0; frame = (-35 -28; 100 100); alpha = 0; opaque = NO; userInteractionEnabled = NO; tag = 1886548836; layer = <CALayer: 0x6237620>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x607ea20; frame = (0 7; 30 30); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x607ea50>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIButtonLabel: 0x6238170; frame = (35 14; 46 16); text = 'Gallery'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x62389d0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIButton: 0x6234a50; frame = (305 0; 475 45); opaque = NO; autoresize = W+BM; layer = <CALayer: 0x6234a00>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x6234ae0; frame = (-35 -28; 100 100); alpha = 0; opaque = NO; userInteractionEnabled = NO; tag = 1886548836; layer = <CALayer: 0x6234b10>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x607e940; frame = (0 7; 30 30); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x607e970>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIButtonLabel: 0x6235670; frame = (35 14; 64 16); text = 'Education'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x6235ed0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIButton: 0x6235f30; frame = (435 0; 455 45); opaque = NO; autoresize = W+BM; layer = <CALayer: 0x6235f00>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x6235fc0; frame = (-35 -28; 100 100); alpha = 0; opaque = NO; userInteractionEnabled = NO; tag = 1886548836; layer = <CALayer: 0x6235ff0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x607e7b0; frame = (0 7; 30 30); clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x607e7e0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIButtonLabel: 0x6236b80; frame = (35 14; 83 16); text = 'Appointment'; clipsToBounds = YES; opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x6236bf0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-<UIView: 0x623a370; frame = (0 0; 768 1004); hidden = YES; opaque = NO; autoresize = W+H; userInteractionEnabled = NO; layer = <CALayer: 0x623a3a0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-<UIView: 0x6239f40; frame = (234 427; 300 150); autoresize = LM+RM+TM+BM; userInteractionEnabled = NO; layer = <CALayer: 0x6239f70>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UILabel: 0x6239fa0; frame = (0 20; 300 22); text = 'Loading...'; clipsToBounds = YES; opaque = NO; autoresize = W+BM; userInteractionEnabled = NO; layer = <CALayer: 0x623a010>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UILabel: 0x623a120; frame = (0 40; 300 35); text = 'This may take a few minut...'; clipsToBounds = YES; opaque = NO; autoresize = W+BM; userInteractionEnabled = NO; layer = <CALayer: 0x623a190>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIActivityIndicatorView: 0x6238a70; frame = (132 93; 37 37); opaque = NO; autoresize = LM+RM+TM+BM; animations = { contents=<CAKeyframeAnimation: 0x605f810>; }; layer = <CALayer: 0x6238ad0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-<UIView: 0x62307e0; frame = (54 68; 660 916); hidden = YES; autoresize = LM+RM+H; layer = <CALayer: 0x6230810>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-<UIImageView: 0x6230840; frame = (0 0; 660 916); alpha = 0.75; hidden = YES; autoresize = W+H; userInteractionEnabled = NO; layer = <CALayer: 0x6230870>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-<UIPageControl: 0x621b7b0; frame = (0 887; 660 36); opaque = NO; autoresize = W+TM; layer = <CALayer: 0x621b870>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIImageView: 0x621ed20; frame = (279 15; 6 6); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x62215a0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIImageView: 0x621a620; frame = (295 15; 6 6); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x621b5c0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIImageView: 0x622d210; frame = (311 15; 6 6); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x621ca40>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIImageView: 0x621ca70; frame = (327 15; 6 6); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x621caa0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIImageView: 0x621cad0; frame = (343 15; 6 6); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x621cb00>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIImageView: 0x621cb30; frame = (359 15; 6 6); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x621cb60>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIImageView: 0x6226910; frame = (375 15; 6 6); opaque = NO; userInteractionEnabled = NO; layer = <CALayer: 0x621ed50>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-<UIScrollView: 0x623e9a0; frame = (0 0; 660 896); clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x623c520>; contentOffset: {0, 0}>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-<UIView: 0x6248070; frame = (0 0; 660 896); autoresize = W+H; layer = <CALayer: 0x62480a0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UILabel: 0x62480d0; frame = (0 0; 660 35); text = 'About Us'; clipsToBounds = YES; opaque = NO; autoresize = W+BM; userInteractionEnabled = NO; layer = <CALayer: 0x6248140>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UIImageView: 0x621f280; frame = (0 50; 660 200); hidden = YES; autoresize = W+BM; userInteractionEnabled = NO; layer = <CALayer: 0x623bc70>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-<UITextView: 0x621db30; frame = (20 35; 620 646); text = ''; clipsToBounds = YES; autoresize = W+H; layer = <CALayer: 0x6237ce0>; contentOffset: {0, 0}>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-|-<UITextSelectionView: 0x6232840; frame = (0 0; 0 0); userInteractionEnabled = NO; layer = <CALayer: 0x62328e0>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-|-<UIImageView: 0x6012950; frame = (615 266; 5 124); alpha = 0; opaque = NO; autoresize = LM; userInteractionEnabled = NO; layer = <CALayer: 0x6069b90>>
[Line: 472] -[iPadRootViewController printViewHierarchy:depth:]: |-|-|-|-|-|-|-|-<UIWebDocumentView: 0x6a65e00; frame = (0 0; 620 50); text = ''; opaque = NO; userInteractionEnabled = NO; layer = <UIWebLayer: 0x6236980>>