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Test relations between main properties of `UIView`
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import UIKit | |
extension UIView { | |
func dumpProperties() { | |
print(""" | |
▿ | |
- bounds: \(bounds) | |
- frame: \(frame) | |
- center: \(center) | |
- transform: \(transform) | |
""") | |
} | |
} | |
let superview = UIView() | |
let subview = UIView() | |
superview.addSubview(subview) | |
test(subview) | |
private func test(_ view: UIView) { | |
view.frame = CGRect(x: 10, y: 10, width: 20, height: 30) | |
view.bounds.origin = CGPoint(x: 5, y: 5) | |
view.dumpProperties() | |
// changing size from bounds will affect both frame(origin + size) and bounds(size), but not center | |
view.bounds.size = CGSize(width: 10, height: 10) | |
view.dumpProperties() | |
// changing size from frame will affect both frame(size) and bounds(size) and center, but not frame.origin | |
// note this difference because `CGRect` is a value object, this may seem unresonable to you | |
view.frame.size = CGSize(width: 20, height: 20) | |
view.dumpProperties() | |
// changing transform will affect frame(origin+size), but not center or bounds | |
view.transform = CGAffineTransform(scaleX: 1.5, y: 1.5) | |
view.dumpProperties() | |
// changing frame/origin will not affect transform, so bounds.size may not be same with frame.size | |
view.frame = CGRect(x: 0, y: 0, width: 5, height: 5) | |
view.bounds.origin = CGPoint(x: 5, y: 5) | |
view.dumpProperties() | |
view.bounds.size = CGSize(width: 5, height: 5) | |
view.dumpProperties() | |
// changing center will only affect frame.origin | |
view.center = CGPoint(x: 0, y: 0) | |
view.dumpProperties() | |
} | |
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