Creating simple, cool and smooth animations in iOS does not require to use external framework, all you need is already in iOS SDK.
This is an example on how to animate a UIView using the method:
UIView.animateWithDuration(1.0, animations)
for create excellent animations with a few lines of code in Swift, using the UIKit framework.
You can download my project (optimized for run on iPhone 6) for see the code and run the application for see the animations, just choose one on the main menu; in my example I use the view of an UIImage for the animations on a blurred background.
In addition to my code I suggest you to read the following description on how these animations work and how implement a blurry effect on UIImage.
## Animations
### 1. Growing animation 
For add a growing animation to your UIView you need to set a initial and final state for the animation. To scale a view, you need to create a **CGAffineTransformMakeScale** and set it to the transform property of your UIView. So in your **viewDidLoad** use:
yourView.transform = CGAffineTransformMakeScale(0.0, 0.0)
and in your viewDidAppear just use this:
UIView.animateWithDuration(1, delay: 0.0, options: nil, animations: {
self.yourView.transform = CGAffineTransformMakeScale(1, 1)
}, completion: nil)
The first 1 is the duration of the animation in seconds and you can obviously set what do you want.
As you can see you need to write just a few lines for an impressive and smooth animation because the UIView automatically renders the animations for you, it needs only a initial and final state.
### 2. Spring animation 
This animation works similar to previous; the initial state is the same and the only thing that you need to change is the method in your **viewDidAppear** with this:
UIView.animateWithDuration(1, delay: 0.0, usingSpringWithDamping: 0.5,
initialSpringVelocity: 0.5, options: nil, animations: {
self.yourView.transform = CGAffineTransformMakeScale(1, 1)
}, completion: nil)
As you can see this method uses two more parameters unlike the previous, the damping and initialSpringVelocity:
- damping how much resistance the spring has; if you want to increase oscillation just set a lower value;
- initialSpringVelocity the initial spring velocity.
### 3. Slide up animation 
For the slide up animation you need to use another transform function in sostitution to the previous, the **CGAffineTransformMakeTranslation(x, y)**.
The reason is that for a slide up animation you need first move the view off screen and then put it back on the screen where you need.
So in your **viewDidLoad** just use:
yourView.transform = CGAffineTransformMakeTranslation(0, 500)
This moves the view off screen, in this example at the bottom.
Now in the viewDidAppear you can show your view with:
UIView.animateWithDuration(1, delay: 0.0, usingSpringWithDamping: 0.5,
initialSpringVelocity: 0.5, options: nil, animations: {
self.yourView.transform = CGAffineTransformMakeScale(1, 1)
}, completion: nil)
### 4. Spring + slide up 
Finally a great example for show that you can easily combine two animations using the function:
CGAffineTransformConcat(transform1, transform2)
In my code I decide to use the spring and the slide up animation together. So in the viewDidLoad method you need to use the two previous function for set up the animations:
let scale = CGAffineTransformMakeScale(0.0, 0.0)
let translate = CGAffineTransformMakeTranslation(0, 500)
yourView.transform = CGAffineTransformConcat(scale, translate)
Intuitively in the viewDidAppear you need this code that use two animations:
UIView.animateWithDuration(1, delay: 0.0, usingSpringWithDamping: 0.6,
initialSpringVelocity: 0.5, options: nil, animations: {
let scale = CGAffineTransformMakeScale(1, 1)
let translate = CGAffineTransformMakeTranslation(0, 0)
self.yourView.transform = CGAffineTransformConcat(scale, translate)
}, completion: nil)
That's it!
## Blurry effect
For conclude just a few words about the blurry effect, a cool effect but really easy to use!
To implement this effect you need to use the UIBlurEffect object just like this:
var blurEffect = UIBlurEffect(style: UIBlurEffectStyle.Dark)
var blurEffectView = UIVisualEffectView(effect: blurEffect)
blurEffectView.frame = view.bounds
yourImage.addSubview(blurEffectView)
Just four lines and you can create cool backgrounds for your apps: create the effect, use it for a blurEffectView, set up the frame and add the view!
Remember that the UIBlurEffect offers three different styles: Dark, Light and ExtraLight, so find out your favorite for your need.