iOS - Arrange subviews in circular shape - iphone

Question

I have a bunch of views in my app. I would like to arrange them in a circular shape and change their center depending on the number of views present.
So, if there are 3 views they would look like a triangle, but would still form a circle. If there are 4 it would look like a square but still form a circle, and so on...
In short, the centers of all views would sit on a imaginary circle.
Any suggestions?

Answer 1

This is the code I used in one of my projects, hope it helps.
// you must set both of these
CGPoint centerOfCircle;
float radius;
int count = 0;
float angleStep = 2.0f * M_PI / [arrayOfViews count];
for (UIView *view in arrayOfViews) {
float xPos = cosf(angleStep * count) * radius;
float yPos = sinf(angleStep * count) * radius;
view.center = CGPointMake(centerOfCircle.x + xPos, centerOfCircle.y +yPos);
count++;
}

Answer 2

Here's a Swift 3 version of the accepted answer, as an UIView extension with offset arguments:
public extension UIView {
public func distributeSubviewsInACircle(xOffset: CGFloat, yOffset: CGFloat) {
let center = CGPoint(x: self.bounds.size.width / 2, y: self.bounds.size.height / 2)
let radius: CGFloat = self.bounds.size.width / 2
let angleStep: CGFloat = 2 * CGFloat(Double.pi) / CGFloat(self.subviews.count)
var count = 0
for subview in self.subviews {
let xPos = center.x + CGFloat(cosf(Float(angleStep) * Float(count))) * (radius - xOffset)
let yPos = center.y + CGFloat(sinf(Float(angleStep) * Float(count))) * (radius - yOffset)
subview.center = CGPoint(x: xPos, y: yPos)
count += 1
}
}
}

Answer 3

You could divide the degrees of a circle (360 degrees or 2π radians) by the number of views you have, then adjust their centers based on the angle and the distance from the centre.
Here are some functions I use:
// These calculate the x and y offset from the center by using the angle in radians
#define LengthDir_X(__Length__,__Direction__) (cos(__Direction__)*__Length__)
#define LengthDir_Y(__Length__,__Direction__) (sin(__Direction__)*__Length__)
// I use this to convert degrees to radians and back if I have to
#define DegToRad(__ANGLE__) (((__ANGLE__) * 2.0 * M_PI) / 360.0)
#define RadToDeg(__ANGLE__) (((__ANGLE__) * 360) / (2.0 * M_PI))