swift 3.0 UIView + Extension fra

import Foundation
import UIKit

extension UIView {
    
    /// X
    public var x: CGFloat{
        get{
            return self.frame.origin.x
        }
        set{
            var r = self.frame
            r.origin.x = newValue
            self.frame = r
        }
    }
    
    /// Y
    public var y: CGFloat{
        get{
            return self.frame.origin.y
        }
        set{
            var r = self.frame
            r.origin.y = newValue
            self.frame = r
        }
    }
    
    /// 右边界的X值
    public var rightX: CGFloat{
        get{
            return self.x + self.width
        }
        set{
            var r = self.frame
            r.origin.x = newValue - frame.size.width
            self.frame = r
        }
    }
    
    /// 下边界的Y值
    public var bottomY: CGFloat{
        get{
            return self.y + self.height
        }
        set{
            var r = self.frame
            r.origin.y = newValue - frame.size.height
            self.frame = r
        }
    }
    
    /// centerX
    public var centerX : CGFloat{
        get{
            return self.center.x
        }
        set{
            self.center = CGPoint(x: newValue, y: self.center.y)
        }
    }
    
    /// centerY
    public var centerY : CGFloat{
        get{
            return self.center.y
        }
        set{
            self.center = CGPoint(x: self.center.x, y: newValue)
        }
    }
    
    /// width
    public var width: CGFloat{
        get{
            return self.frame.size.width
        }
        set{
            var r = self.frame
            r.size.width = newValue
            self.frame = r
        }
    }
    /// height
    public var height: CGFloat{
        get{
            return self.frame.size.height
        }
        set{
            var r = self.frame
            r.size.height = newValue
            self.frame = r
        }
    }
    
    /// origin
    public var origin: CGPoint{
        get{
            return self.frame.origin
        }
        set{
            self.x = newValue.x
            self.y = newValue.y
        }
    }
    
    /// size
    public var size: CGSize{
        get{
            return self.frame.size
        }
        set{
            self.width = newValue.width
            self.height = newValue.height
        }
    }
    
}