CAShapeLayer Class Creation

Question

I found a fantastic tutorial written in Swift for creating an animation when my app opens. It's written in Swift, so I'm Objective-C-ifying it for a project I'm working on, but I'm running into a little trouble adding my animation. Swift works, but I can't figure out what's wrong w/ my Objective-C version.

Creating a Complex Loading Animation in Swift

Swift Version of CAShapeLayer Class:

func expand() {
    var expandAnimation: CABasicAnimation = CABasicAnimation(keyPath: "path")
    expandAnimation.fromValue = ovalPathSmall.CGPath
    expandAnimation.toValue = ovalPathLarge.CGPath
    expandAnimation.duration = animationDuration
    expandAnimation.fillMode = kCAFillModeForwards
    expandAnimation.removedOnCompletion = false
    // the following line I'm having trouble converting to Objective-C
    addAnimation(expandAnimation, forKey: nil)
}

Objective-C Version:

- (void)expand {
    CABasicAnimation *expandAnimation = [CABasicAnimation animationWithKeyPath:@"path"];
    expandAnimation.fromValue = (__bridge id)(_ovalPathSmall.CGPath);
    expandAnimation.toValue = (__bridge id)(_ovalPathSquishHorizontal.CGPath);
    expandAnimation.duration = self.animationDuration;
    expandAnimation.fillMode = kCAFillModeForwards;
    expandAnimation.removedOnCompletion = NO;
    // I can't figure out how to "convert" this to Objective-C
    // addAnimation(expandAnimation, forKey: nil)

}

Initializers:

I suspect I'm mucking something up with the initializer, so here's the code for the working Swift one and my Objective-C-ified version below.

Swift Version:

let animationDuration: CFTimeInterval = 0.3

override init!() {
    super.init()
    fillColor = Colors.red.CGColor
    path = ovalPathSmall.CGPath
}

required init(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

Objective-C Version:

This is my attempt at mimicking the initializer in my .m file:

- (instancetype)init
{
    self = [super init];
    if (self) {
        self.animationDuration = 0.3;
        self.fillColor = [UIColor redColor].CGColor;
        self.path = self.ovalPathSmall.CGPath;
    }
    return self;
}

Thank you for reading and I welcome your input.

Have you considered leaving it in swift, just using interop? All roads lead to Swift at this point, you might help yourself in the end by doing less work now. — Chris Conover, Jul 22 '15 at 21:47
At this point, I just want to get this launch screen done and wrap up the project ;) Can you point me to a post re: how to bring Swift into an Objective-C project? Everything I've seen is going the other way. I'm going all-Swift all the time going forward now that they're on 2.0. — Adrian, Jul 22 '15 at 21:52

Chris Conover · Accepted Answer · 2015-07-22T22:03:39.950

1

To answer your immediate question, I think you just need [self addAnimation...], but I don't know what you have tried.

To answer your comment though, at least at this point, it is pretty easy. See the mixing and matching section of: https://developer.apple.com/library/ios/documentation/Swift/Conceptual/BuildingCocoaApps/MixandMatch.html#//apple_ref/doc/uid/TP40014216-CH10-XID_78.

The short version is that the Swift compiler runs first, and generates Obj-C stubs that the Obj-C compiler can understand in a single header file based on your project name. This file is generated in the build output (Derived Data etc). You need to import that file into your Ojb-C code, per the example in the above link.

#import "ProductModuleName-Swift.h"

edited Jul 22 '15 at 22:03

answered Jul 22 '15 at 21:55

Chris Conover

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Thank you! I learned something here, so the frustration was worth it ;) – Adrian Jul 22 '15 at 22:15
Your post and this one got me over the finish line! http://stackoverflow.com/questions/24206732/cant-use-swift-classes-inside-objective-c – Adrian Jul 23 '15 at 02:09

CAShapeLayer Class Creation

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