Writing a new class with singleton

Question

Hi I am creating a new class CNAnimations. The purpose of this class is to perform some simple animations with ease and without using the same code a lot of times. So, I would like it to behave like [UIView animateWithDuration...]. Should I create a singleton class and init it in the appdelegate and the access it: [CNAnimations moveRight:view] ? Is that correct? Please note that the class will be used by a lot of uilabels,textfields etc from different classes.

Simple code:

  -(void)moveRL:(UIView*)view{

CAKeyframeAnimation * anim = [ CAKeyframeAnimation animationWithKeyPath:@"transform" ] ;
anim.values = @[ [ NSValue valueWithCATransform3D:CATransform3DMakeTranslation(-5.0f, 0.0f, 0.0f) ], [ NSValue valueWithCATransform3D:CATransform3DMakeTranslation(5.0f, 0.0f, 0.0f) ] ] ;
anim.autoreverses = YES ;
anim.repeatCount = 2.0f ;
anim.duration = 2.0f ;

[view.layer addAnimation:anim forKey:nil ] ;

}

If you're going to create a singleton and init it in the app delegate, you might as well just use a property of the app delegate. — Hot Licks, Jul 14 '14 at 21:43

score 3 · Answer 1 · answered Jul 14 '14 at 21:37

Since you don't seem to need an object of 'CNAnimations' and it serves more or less as a proxy for kicking off animations, you could simply define all methods at class scope (writing '+' instead of '-'). You can then do [CNAnimation animateWhatever:] without the need to keep a singleton.

score 1 · Accepted Answer · answered Jul 14 '14 at 21:49

Objective-C classes are also an opaque type called Class. This allows you to not have to allocate memory and initialize a class to use a classes factory methods. Factory methods are defined using + instead of -. for example, +(id)moveRL you often use factory methods without realizing it, such as NSString text = [NSString stringWithFormat:"@Hello World!"] The stringWithFormat is the factory method in this example.

Writing a new class with singleton

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