Programmatically getting the "Z" position of a UIView compared to it's siblings - iphone

Question

My class has logic for inserting views in certain levels in the hierarchy.
containerView = [[UIView alloc] init];
shadowView = [[UIView alloc] init];
contentView = [[UIView alloc init];
[containerView addSubview:shadowView];
[containerView insertSubview:contentView belowSubview:shadowView];
Later down the line, it flips them so the shadow view is below the content view instead of above it.
// "Flipping" their positions.
[containerView insertSubview:contentView aboveSubview:shadowView];
UIView has a subviews property returning an NSArray, unfortunately the array does not reflect the view stack ordering.
I want to unit test the placement of the view compared to it's siblings. How can I do that?
Here's an example of a test.
- (void)testViewHierarchyFlipping {
STAssertEquals(containerView, shadowView.superview, nil);
STAssertEquals(containerView, contentView.superview, nil);
// Test that shadowView is ABOVE contentView.
}

Answer 1

You can inspect the containerView.subviews property to determine the Z position of each subview.
Items at the beginning of the array are deeper than items at the end of the array.
I believe this should work for your test, although I don't have access to Xcode to verify that it's correct at the moment.
- (void)testViewHierarchyFlipping {
STAssertEquals(containerView, shadowView.superview, nil);
STAssertEquals(containerView, contentView.superview, nil);
// Test that shadowView is ABOVE contentView.
UIView *topView = (UIView *)[[containerView subviews] lastObject];
UIView *bottomView = (UIView *)[[containerView subviews] objectAtIndex:0];
STAssertEquals(shadowView, topView, nil);
STAssertEquals(contentView, bottomView, nil);
}