CODEWITHSUNDEEP
ioscocoa-touchuiviewuiviewcontroller
Ted
Ted

Reputation: 3875

getting a subview's WINDOW coordinates issue with convertRect

from main viewController's ViewDidAppear

UIView* parent = [[UIView alloc] initWithFrame:CGRectMake(100, 100, 100, 100)];
UIView* child1 = [[UIView alloc] initWithFrame:CGRectMake(30, 30, 60, 60)];
UIView* child2 = [[UIView alloc] initWithFrame:CGRectMake(10, 10, 20, 20)];

[parent setBackgroundColor:[UIColor redColor]];
[child1 setBackgroundColor:[UIColor blackColor]];
[child2 setBackgroundColor:[UIColor greenColor]];

[child1 addSubview:child2];
[parent addSubview:child1];
[self.view addSubview:parent];

NSLog(@"Absolute coordinates of child2: %@",NSStringFromCGRect([child2 convertRect:child2.frame toView:nil] ));

abs point of child2: {{150, 170}, {20, 20}}

I was expecting the origins to be (140,140, 20,20).

Why the extra 10 for the X and 30 for the Y?

Upvotes: 1

Views: 3150

Answers (1)

Mike Pollard
Mike Pollard

Reputation: 10195

What you need to call is:

[child2.superview convertRect:child2.frame toView:nil]

NOT

[child2 convertRect:child2.frame toView:nil]

ie. you need to call convertRect: on the view that contains the frame you are converting.

Then you'll probably find X == 140 and Y == 160, with the extra 20 Y being the status bar given that self.view lives within the UIWindow beneath it.

Upvotes: 10

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