Annotation error in Swift for loop with array and UIView - nsarray

Question

I thought it would be a great learning experiment to take a small Obj-C library and convert it to Swift. Since I eventually want to use this library in an app, I found the Path app menu example here: https://github.com/yourabi/PathMenuExample
I think I've done an okay job of converting and searching for answers as I'm just starting out with Obj-C and Swift. But now I'm stuck with an error I can't find a solution for.
ExpandableNavigation.swift
import Foundation
import UIKit;
class ExpandableNavigation: NSObject {
var mainButton: UIButton;
var menuItems: NSArray;
var radius: CGFloat;
var speed: CGFloat;
var bounce: CGFloat;
var bounceSpeed: CGFloat;
var expanded: Bool;
var transition: Bool;
init(menuItems: NSArray, mainButton: UIButton, radius: CGFloat) {
self.menuItems = menuItems;
self.mainButton = mainButton;
self.radius = radius;
self.speed = 0.15;
self.bounce = 0.225;
self.bounceSpeed = 0.1;
expanded = false;
transition = false;
super.init()
if self.mainButton != nil {
for view: UIView in self.menuItems {
view.center = self.mainButton.center;
}
self.mainButton.addTarget(self, action:"press", forControlEvents: UIControlEvents.TouchUpInside);
}
}
func expand() -> Void {
transition = true;
UIView.animateWithDuration(0.15, animations: {
self.mainButton.transform = CGAffineTransformMakeRotation(45.0 * M_PI/180)
})
for view: UIView in self.menuItems {
var index: Int? = findIndex(self.menuItems, valueToFind: view);
var oneOverCount: Float;
if self.menuItems.count <= 1 {
oneOverCount = 1.0;
} else {
oneOverCount = (1.0 / Float(self.menuItems.count - 1));
}
var indexOverCount: CGFloat = CGFloat(index!) * CGFloat(oneOverCount);
var rad: CGFloat = (1.0 - CGFloat(indexOverCount)) * 90.0 * CGFloat(M_PI) / 180.0;
var rotation: CGAffineTransform = CGAffineTransformMakeRotation(rad);
var x: CGFloat = (self.radius + self.bounce * self.radius) * rotation.a;
var y: CGFloat = (self.radius + self.bounce * self.radius) * rotation.c;
var center: CGPoint = CGPointMake(view.center.x + x, view.center.y + y);
UIView.animateWithDuration(self.speed,
delay: self.speed * indexOverCount,
options: UIViewAnimationOptions.CurveEaseIn,
animations: {
view.center = center;
},
completion: {(finished: Bool) in
UIView.animateWithDuration(self.bounceSpeed,
animations: {
var x: CGFloat = self.bounce * self.radius * rotation.a;
var y: CGFloat = self.bounce * self.radius * rotation.c;
var center: CGPoint = CGPointMake(view.center.x + x, view.center.y + y);
view.center = center;
});
if view == (self.menuItems.endIndex - 1) {
self.expanded = true;
self.transition = false;
}
})
}
}
func collapse() -> Void {
transition = true;
}
#IBAction func press(sender: AnyObject) {
if !self.transition {
if !self.expanded {
self.expand();
} else {
self.collapse();
}
}
}
func findIndex<T: Equatable>(array: T[], valueToFind: T) -> Int? {
for (index, value) in enumerate(array) {
if value == valueToFind {
return index
}
}
return nil
}
}
Error on ExpandableNavigation.swift
Error: Type annotation does not match contextual type 'AnyObject'
This error occurs both in the init() and the expand() methods where it says
for view: UIView in self.menuItems {
I tried making the array UIView[] but that causes errors else where.
ViewController.swift - For reference
class ViewController: UIViewController {
#IBOutlet var expandNavMainButton: UIButton;
#IBOutlet var expandNavCheckInButton: UIButton;
#IBOutlet var expandNavReviewButton: UIButton;
#IBOutlet var expandNavPhotoButton: UIButton;
#IBOutlet var expandNavStatusButton: UIButton;
var expandableNavigation: ExpandableNavigation;
init(coder aDecoder: NSCoder!) {
var buttons: NSArray = [expandNavCheckInButton, expandNavReviewButton, expandNavPhotoButton, expandNavStatusButton];
var myRadius: CGFloat = 120.0
self.expandableNavigation = ExpandableNavigation(menuItems: buttons, mainButton: self.expandNavMainButton, radius: myRadius);
super.init(coder: aDecoder)
}

Answer 1

Swift will not do any implicit casting for you for safety. It will not cast AnyObject (which is the type that NSArray stores) to a UIView without an explicit cast. You should do the following:
for obj : AnyObject in menuItems {
if let view = obj as? UIView {
view.center = self.mainButton.center;
}
}
This loops through the array of menu items with an AnyObject and the checks if obj is a view before casting it as one.