How do you display an image at the maximum available space? - ios

Question

I check if the image is vertical or horizontal. If it is horizontal, I rotate it:
#IBOutlet private weak var img: UIImageView!
img.image = file.image
let imageSize = file.image?.size
let imgWidth = imageSize?.width ?? 0
let imgHeight = imageSize?.height ?? 0
if imgWidth > imgHeight {
print("IMG HORIZONTAL")
imgDetail.transform = imgDetail.transform.rotated(by: .pi / 2)
} else {
print("IMG VERTICAL")
}
But it leaves me a space around the image. I would like it to be at the maximum size of the UIImageView.

Answer 1

Try this, declare your imageView:
let YourImageView: UIImageView = {
let iv = UIImageView()
iv.image = UIImage(named: "myImage")?.withRenderingMode(.alwaysOriginal)
iv.backgroundColor = .clear
iv.contentMode = .scaleAspectFit
iv.isUserInteractionEnabled = true
iv.clipsToBounds = true
iv.translatesAutoresizingMaskIntoConstraints = false
return iv
}()
in viewDidLoad set if statement and call setupConstraints:
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
guard let imgWidth = YourImageView.image?.size.width else { return }
guard let imgHeight = YourImageView.image?.size.height else { return }
if imgWidth > imgHeight {
print("IMG HORIZONTAL")
guard let image = YourImageView.image else { return }
let newImage = image.rotate(radians: .pi / 2) // image rotation
YourImageView.image = newImage
} else {
print("IMG VERTICAL")
}
setupConstraints()
}
set up constraints
fileprivate func setupConstraints() {
view.addSubview(YourImageView)
YourImageView.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
YourImageView.centerYAnchor.constraint(equalTo: view.centerYAnchor).isActive = true
YourImageView.leadingAnchor.constraint(equalTo: view.leadingAnchor).isActive = true
YourImageView.trailingAnchor.constraint(equalTo: view.trailingAnchor).isActive = true
}
write image extension
extension UIImage {
func rotate(radians: Float) -> UIImage? {
var newSize = CGRect(origin: CGPoint.zero, size: self.size).applying(CGAffineTransform(rotationAngle: CGFloat(radians))).size
// Trim off the extremely small float value to prevent core graphics from rounding it up
newSize.width = floor(newSize.width)
newSize.height = floor(newSize.height)
UIGraphicsBeginImageContextWithOptions(newSize, false, self.scale)
guard let context = UIGraphicsGetCurrentContext() else { return UIImage()}
// Move origin to middle
context.translateBy(x: newSize.width/2, y: newSize.height/2)
// Rotate around middle
context.rotate(by: CGFloat(radians))
// Draw the image at its center
self.draw(in: CGRect(x: -self.size.width/2, y: -self.size.height/2, width: self.size.width, height: self.size.height))
let newImage = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return newImage
}
}
this is the result normal (without image rotate extension call) and rotated (with image rotate extension call):