MKTween

Very simple and lightweight tween framework in Swift 5.0. No objects/views bindings for a more flexible use. Uses CADisplayLink or NSTimer with time interval parameters.

Since 4.0+ you can now use Groups and Sequences to chain animations. If you used 3.2 and lower, you will have to update your code to use 4.0+!

Please share if you have any suggestions or comments. Thanks

Requirements

• iOS 11.0+
• Xcode 10.2+

Usage

Tween timing functions:

Timing.linear
Timing.backOut
Timing.backIn
Timing.backInOut
Timing.bounceOut
Timing.bounceIn
Timing.bounceInOut
Timing.circleOut
Timing.circleIn
Timing.circleInOut
Timing.cubicOut
Timing.cubicIn
Timing.cubicInOut
Timing.elasticOut
Timing.elasticIn
Timing.elasticInOut
Timing.expoOut
Timing.expoIn
Timing.expoInOut
Timing.quadOut
Timing.quadIn
Timing.quadInOut
Timing.quartOut
Timing.quartIn
Timing.quartInOut
Timing.quintOut
Timing.quintIn
Timing.quintInOut
Timing.sineOut
Timing.sineIn
Timing.sineInOut
Timing.custom()

Single Tween:

let period = Period<CGFloat>(start: 0, end: 1).set(update: { (period) in
    print(period.progress)
}) {
    print("complete")
}.set(timingMode: .elasticInOut)
Tween.shared.add(period: period)

Now supports CGPoint, CGSize, CGRect and UIColor.

let period = Period<CGRect>(start: .zero, end: CGRect(x: 10, y: 10, width: 100, height: 200), duration: 2).set(update: { (period) in
    print(period.progress)
}) {
    print("complete")
}.set(timingMode: .elasticInOut)
Tween.shared.add(period: period)

Group Tween

let periods: [BasePeriod] = [
    Period<CGFloat>(start: 0, end: 200, duration: 1).set(update: { [weak self] period in
        if let circleView = self?.circleView {
            var origin = circleView.center
            origin.x = 20 + (period.progress)
            circleView.center = origin
        }
    }).set(timingMode: .linear),
    Period<CGFloat>(start: 0, end: 200, duration: 1).set(update: { [weak self] period in
        if let circleView = self?.circleView {
            var origin = circleView.center
            origin.y = 160 + (period.progress)
            circleView.center = origin
        }
    }).set(timingMode: .quadInOut)
]
let group = Group(periods: periods)
    .set(update: { group in
        print("\(group.periodFinished.filter { $0 }.count) finished on \(group.periodFinished.count)")
    }) {
        print("complete")
}
Tween.shared.add(period: group)

Sequence Tween

let periods: [BasePeriod] = [
    Period<CGFloat>(start: 0, end: 200, duration: 1).set(update: { [weak self] period in
        if let circleView = self?.circleView {
            var origin = circleView.center
            origin.x = 20 + (period.progress)
            circleView.center = origin
        }
    }).set(timingMode: .linear),
    Period<CGFloat>(start: 0, end: 200, duration: 1).set(update: { [weak self] period in
        if let circleView = self?.circleView {
            var origin = circleView.center
            origin.y = 160 + (period.progress)
            circleView.center = origin
        }
    }).set(timingMode: .quadInOut)
]
let sequence = MKTween.Sequence(periods: periods)
    .set(update: { sequence in
        print("\(sequence.currentPeriodIndex) finished on \(sequence.periods.count)")
    }) {
        print("complete")
}
Tween.shared.add(period: sequence)

You can also combine Group and Sequence as you want.

Tween instances

Many times I have seen unique way of using tweens to be init in only one way and removes the ability of using multiple instances. So you can be sure to not forget variables to setup. Here ways you can allocate:

let tween = Tween.shared
let tween = Tween.shared()
let tween = Tween.shared(.default) // Use CADisplayLink 
let tween = Tween.shared(.displayLink) // Use CADisplayLink 
let tween = Tween.shared(.timer) // Use NSTimer 
let tween = Tween.shared(.none) // If you don't want any tick system to use your own, calling update(timeStamp:) yourself

let tween = Tween()
let tween = Tween(.default)
let tween = Tween(.displayLink)
let tween = Tween(.timer)
let tween = Tween(.none)

Technics

Setting up time intervals

public var frameInterval: Int = 1 // Used for CADisplayLink. Defines how many display frames must pass between each time the display link fires. Can check apple documentation.
public var timerInterval: NSTimeInterval = 1.0/60.0 // Base on a 60 fps rate by default.

**Get tween values without using ticks or **

let period = Period<CGFloat>(duration:1).set(timingMode: .backInOut) // will default to startValue 0 and endValue to 1
let tweenValues = period.tweenValues(UInt(count))

tweenValues.enumerated().forEach { index, progress in
    
    // do something with it
}

Pause

tween.paused = true

Reverse a tween while it is running

period.reverse() // This will basically exchange startValue and endValue, but will use the same time already progressed to animated the other side.

Installation

Embedded frameworks require a minimum deployment target of iOS 11.

CocoaPods

CocoaPods is a dependency manager for Cocoa projects. You can install it with the following command:

$ gem install cocoapods

CocoaPods 1.6.1+ is required to build MKTween 4.0+.

To integrate MKTween into your Xcode project using CocoaPods, specify it in your Podfile:

Finally working!!!

source 'https://github.com/CocoaPods/Specs.git'
platform :ios, '11.0'
use_frameworks!

pod 'MKTween'

Then, run the following command:

$ pod install

Embedded Framework

• Open up Terminal, cd into your top-level project directory, and run the following command "if" your project is not initialized as a git repository:

$ git init

• Add MKTween as a git submodule by running the following command:

$ git submodule add https://github.com/kmalkic/MKTween.git

• Open the new MKTween folder, and drag the MKTween.xcodeproj into the Project Navigator of your application's Xcode project.

  It should appear nested underneath your application's blue project icon. Whether it is above or below all the other Xcode groups does not matter.

• Select the MKTween.xcodeproj in the Project Navigator and verify the deployment target matches that of your application target.

• Next, select your application project in the Project Navigator (blue project icon) to navigate to the target configuration window and select the application target under the "Targets" heading in the sidebar.

• In the tab bar at the top of that window, open the "General" panel.

• Click on the + button under the "Embedded Binaries" section.

• You will see two different MKTween.xcodeproj folders each with two different versions of the MKTween.framework nested inside a Products folder.

  It does not matter which Products folder you choose from, but it does matter whether you choose the top or bottom MKTween.framework.

• And that's it!

The MKTween.framework is automagically added as a target dependency, linked framework and embedded framework in a copy files build phase which is all you need to build on the simulator and a device.

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Credits

Kevin Malkic

License

MKTween is released under the MIT license. See LICENSE for details.