How can you rotate text for UIButton and UILabel in Swift?

Suragch picture Suragch · Feb 25, 2015 · Viewed 57.8k times · Source

How can you rotate text for UIButton and UILabel? 90 degrees, 180 degrees.

Note: Before you mark this as a duplicate, I am intentionally modelling my question as a Swift version of this one: How can you rotate text for UIButton and UILabel in Objective-C?

Answer

Suragch picture Suragch · Feb 25, 2015

I am putting my answer in a similar format to this answer.

Here is the original label:

enter image description here

Rotate 90 degrees clockwise:

yourLabelName.transform = CGAffineTransform(rotationAngle: CGFloat.pi / 2)

enter image description here

Rotate 180 degrees:

yourLabelName.transform = CGAffineTransform(rotationAngle: CGFloat.pi)

enter image description here

Rotate 90 degrees counterclockwise:

yourLabelName.transform = CGAffineTransform(rotationAngle: -CGFloat.pi / 2)

enter image description here

Do the same thing to rotate a button. Thankfully the touch events also get rotated so the button is still clickable in its new bounds without having to do anything extra.

yourButtonName.transform = CGAffineTransform(rotationAngle: CGFloat.pi / 2)

Notes:

Documentation for CGAffineTransform

The basic format is CGAffineTransform(rotationAngle: CGFloat) where rotationAngle is in radians, not degrees.

There are 2π radians in a full circle (360 degrees). Swift includes the useful constant CGFloat.pi.

  • CGFloat.pi = π = 180 degrees
  • CGFloat.pi / 2 = π/2 = 90 degrees

Auto Layout:

Auto layout does not work with rotated views. (See Frame vs Bounds for an explanation why.) This problem can be solved by creating a custom view. This answer shows how to do it for a UITextView, but it is the same basic concept for a label or button. (Note that you will have to remove the CGAffineTransformScale line in that answer since you don't need to mirror the text.)

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