Get height of UIView based on specific width before showing view - ios

Question

I have a UIView which I have designed in Interface Builder. It basically consists out of a header image and some text (UILabel) below. The view is being shown modally with a custom Transition and doesn't fill the whole screen.
There is like a 20 pixels margin on the left and right and 40 px on the top. The UILabel gets filled with some text that's coming from the web. What I want do do, is to find (or should I say predict) the height of the whole view for a specific width. How can I do that?

Answer 1

I had similar problem, but instead of calculating font size and image height you can use this UIView extension that will autosize your view with max width:
extension UIView {
func autosize(maxWidth: CGFloat) {
translatesAutoresizingMaskIntoConstraints = false
let dummyContainerView = UIView(frame: CGRect(x: 0, y: 0, width: maxWidth, height: 10000000))
dummyContainerView.addSubview(self)
dummyContainerView.topAnchor.constraint(equalTo: topAnchor, constant: 0).isActive = true
dummyContainerView.leftAnchor.constraint(equalTo: leftAnchor, constant: 0).isActive = true
dummyContainerView.rightAnchor.constraint(equalTo: rightAnchor, constant: 0).isActive = true
setNeedsLayout()
layoutIfNeeded()
removeFromSuperview()
frame = CGRect(x: 0, y: 0, width: frame.width, height: frame.height)
translatesAutoresizingMaskIntoConstraints = true
}
}
Using this approuch you don't have to worry about your content inside the view.
To use it:
let customView: CustomView = ... //create your view
... // configure all data on your view, e.g. labels with correct text
customView.autosize(maxWidth: 150) // resize your view
view.addSubview(customView) // add your view to any view

Answer 2

You need to have both the picture and the label before calculating the aspected size.
I guess you should use something like this (maybe adding the vertical inter-distance between the imageView and the Label to the sum, and maybe removing the lateral margins from the width):
objective C :
- (CGFloat)preferredHeightFromWidth:(CGFloat)width text:(NSString *)text font:(UIFont *)font image:(UIImage *)image
{
// Calculate label height
CGFloat labelHeight = [text
boundingRectWithSize:CGSizeMake(width, 10000)
options:NSStringDrawingUsesLineFragmentOrigin
attributes:#{NSFontAttributeName:font}
context:[[NSStringDrawingContext alloc] init]
].size.height;
// Calculate image height
CGFloat ratio = image.size.height/ image.size.width;
CGFloat imageHeight = (ratio * width);
// Do the sum
return labelHeight + imageHeight;
}
Swift:
func preferredHeight(width: CGFloat, text: NSString, font: UIFont, image: UIImage) -> CGFloat {
// Calculate Label Height
let labelRect = text.boundingRect(
with: CGSize.init(width: width, height: 10000),
options: .usesLineFragmentOrigin,
attributes: [NSFontAttributeName : font],
context: NSStringDrawingContext())
let labelHeight = labelRect.height
// Calculate Image Height
let ratio = image.size.height / image.size.width
let imageHeight = ratio / width
// Calculate Total Height
let height = labelHeight + imageHeight
// Return Height Value
return height
}
(Thanks to Christopher Hannah for swift version)

Answer 3

Here is the same answer as Alberto, but I have changed it into Swift 3.
func preferredHeight(width: CGFloat, text: NSString, font: UIFont, image: UIImage) -> CGFloat {
// Calculate Label Height
let labelRect = text.boundingRect(
with: CGSize.init(width: width, height: 10000),
options: .usesLineFragmentOrigin,
attributes: [NSFontAttributeName : font],
context: NSStringDrawingContext())
let labelHeight = labelRect.height
// Calculate Image Height
let ratio = image.size.height / image.size.width
let imageHeight = ratio / width
// Calculate Total Height
let height = labelHeight + imageHeight
// Return Height Value
return height
}