Swift UITextView change font size if text is longer than two lines

Question

How can I make a UITextView change its font size so that all of the text fits within a maximum of two lines? If the text fits one or two lines perfectly then I don't want the font size to change. But if the text is any longer, I need it to get smaller. Thanks.

Answer 1

I believe you have a great reason to use UITextView , and thus I think this can be little tricky and needs a lot of testing to see it actually works just as you expected.

What I would suggest is to calculate number of rows by:

let font = yourFont
let size = yourTextView.contentSize
let inset = yourTextView.textContainerInset
let rows = (size.height - inset.top - inset.bottom) / font.lineHeight

Get rows inside textView 's delegate method, something like textView:shouldChangeTextIn:... for instance, and change font size according to this information.

Another suggestion is to make invisible UILabel with properties set like below:

label.font = yourFont
label.frame = CGRect(x: 0, y: 0, width: yourTextView.contentSize.width, height: yourTextView.contentSize.height)
label.numberOfLines = 2
label.adjustFontSizeToFitWidth = true

Then inside textView 's delegate method, update label 's text and

textView.font = label.font

I'm not sure either of these will actually work since I haven't tested them for myself, but I hope this may help you to set a start point for this problem.

Answer 2

Unless you have a specific need to be using a UITextView , I recommend using a UILabel . This code limits a UILabel to two lines and makes its text auto-shrink:

label.numberOfLines = 2
label.adjustsFontSizeToFitWidth = true