Wherever someone leaves my app and lets it go into the background, when they then later open the app, the gradient is no longer cycling.

Is there away to restore the state the gradient was in before being sent to background?

thank you.

I think I should be able to do it with func applicationDidBecomeActive(_ application: UIApplication) { but I don't know how

@cruisediary , I have modified lib with SPM support following way:

• File reorganisation (Sources, Tests folders)
• Package.swift file
• PodSpec file update

When I use pastel through Carthage, I got the following log.

/usr/bin/xcrun xcodebuild -project /Users/minjunju/Desktop/Cart/Carthage/Checkouts/Pastel/Pastel.xcodeproj -scheme Pastel -configuration Release -derivedDataPath /Users/minjunju/Library/Caches/org.carthage.CarthageKit/DerivedData/10.0_10A255/Pastel/0.5.1 -sdk iphoneos ONLY_ACTIVE_ARCH=NO CODE_SIGNING_REQUIRED=NO CODE_SIGN_IDENTITY= CARTHAGE=YES archive -archivePath /var/folders/lm/f53m_74j4ns1xhzfykbfrw0m0000gp/T/Pastel SKIP_INSTALL=YES GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=NO CLANG_ENABLE_CODE_COVERAGE=NO STRIP_INSTALLED_PRODUCT=NO (launched in /Users/minjunju/Desktop/Cart/Carthage/Checkouts/Pastel)User defaults from command line:
    IDEArchivePathOverride = /var/folders/lm/f53m_74j4ns1xhzfykbfrw0m0000gp/T/Pastel
    IDEDerivedDataPathOverride = /Users/minjunju/Library/Caches/org.carthage.CarthageKit/DerivedData/10.0_10A255/Pastel/0.5.1

Build settings from command line:
    CARTHAGE = YES
    CLANG_ENABLE_CODE_COVERAGE = NO
    CODE_SIGN_IDENTITY = 
    CODE_SIGNING_REQUIRED = NO
    GCC_INSTRUMENT_PROGRAM_FLOW_ARCS = NO
    ONLY_ACTIVE_ARCH = NO
    SDKROOT = iphoneos12.0
    SKIP_INSTALL = YES
    STRIP_INSTALLED_PRODUCT = NO

note: Using new build system
note: Planning build
note: Constructing build description
Build system information
warning: The use of Swift 3 @objc inference in Swift 4 mode is deprecated. Please address deprecated @objc inference warnings, test your code with “Use of deprecated Swift 3 @objc inference” logging enabled, and then disable inference by changing the "Swift 3 @objc Inference" build setting to "Default" for the "Pastel" target. (in target 'Pastel')

Build system information
warning: The use of Swift 3 @objc inference in Swift 4 mode is deprecated. Please address deprecated @objc inference warnings, test your code with “Use of deprecated Swift 3 @objc inference” logging enabled, and then disable inference by changing the "Swift 3 @objc Inference" build setting to "Default" for the "Pastel" target. (in target 'Pastel')

Build system information
warning: duplicate output file '/Users/minjunju/Library/Caches/org.carthage.CarthageKit/DerivedData/10.0_10A255/Pastel/0.5.1/Build/Intermediates.noindex/ArchiveIntermediates/Pastel/IntermediateBuildFilesPath/UninstalledProducts/iphoneos/Pastel.framework/.gitkeep' on task: CpResource /Users/minjunju/Desktop/Cart/Carthage/Checkouts/Pastel/Pastel/Classes/.gitkeep /Users/minjunju/Library/Caches/org.carthage.CarthageKit/DerivedData/10.0_10A255/Pastel/0.5.1/Build/Intermediates.noindex/ArchiveIntermediates/Pastel/IntermediateBuildFilesPath/UninstalledProducts/iphoneos/Pastel.framework/.gitkeep (in target 'Pastel')

Build system information
error: Multiple commands produce '/Users/minjunju/Library/Caches/org.carthage.CarthageKit/DerivedData/10.0_10A255/Pastel/0.5.1/Build/Intermediates.noindex/ArchiveIntermediates/Pastel/IntermediateBuildFilesPath/UninstalledProducts/iphoneos/Pastel.framework/.gitkeep':
1) Target 'Pastel' (project 'Pastel') has copy command from '/Users/minjunju/Desktop/Cart/Carthage/Checkouts/Pastel/Pastel/Assets/.gitkeep' to '/Users/minjunju/Library/Caches/org.carthage.CarthageKit/DerivedData/10.0_10A255/Pastel/0.5.1/Build/Intermediates.noindex/ArchiveIntermediates/Pastel/IntermediateBuildFilesPath/UninstalledProducts/iphoneos/Pastel.framework/.gitkeep'
2) Target 'Pastel' (project 'Pastel') has copy command from '/Users/minjunju/Desktop/Cart/Carthage/Checkouts/Pastel/Pastel/Classes/.gitkeep' to '/Users/minjunju/Library/Caches/org.carthage.CarthageKit/DerivedData/10.0_10A255/Pastel/0.5.1/Build/Intermediates.noindex/ArchiveIntermediates/Pastel/IntermediateBuildFilesPath/UninstalledProducts/iphoneos/Pastel.framework/.gitkeep'

** ARCHIVE FAILED **`

I think a problem because of'.gitkeep' exists. so I had deleted the .gitkeep in the Classes folder.

In addition, I don't know a reason that whether you intend to set swift 3 @objc inference to 'on'. I have changed it to default because of proposals

Please review myPR. thank you

Constant has been removed in favor of a forwards property on the CAMediaTimingFillMode type. Solution has been tested on Xcode Version 10.0 beta 2 with Swift 4.2 and a project build for iOS 12.

I added a uiview using storyboard and gave it a class of PastelView

Autolayout contraints: Top space to superview: 0 Trailing/leading space to superview: 0 Height: 45

More or less a uiview that is 45px high and hugs the top/left/right sides of my view.

ViewdidLoad:

self.testview.startPoint = .topRight
self.testview.endPoint = .bottomLeft
self.testview.animationDuration = 3.0
self.testview.setColors(colors: [UIColor(red:0.99, green:0.19, blue:0.35, alpha:1.0),
                                                      UIColor(red:1.00, green:0.37, blue:0.57, alpha:1.0)])
self.testview.startAnimation()

When I run the simulator or test it on a real iphone 5 device everything looks fine, but when I run a iphone 6 plus or test it on a real iphone 6 plus device I can see that the gradient view doesnt cover the whole width, it gets to short on the right side:

The gradient animation still works but it doesnt cover 100% of the width.

This PR migrates the project to use Swift 5.0 by default. No source changes were necessary, so the project should still build with Swift 4.2 if necessary.

I wanted to use PastelView with AVFoundation because I wanted to add some nice gradient effects into my video-editing application. A small issue with AVFoundation is that it works only with CALayer instances and it doesn't allow UIKit controls, so I'm basically stuck with CALayer and can't use PastelView.

So I took PastelView and created a PastelLayer, a CAGradientLayer's subclass, which does almost everything that PastelView can.

class PastelLayer: CAGradientLayer, CAAnimationDelegate {
    private struct Animation {
        static let keyPath = "colors"
        static let key = "ColorChange"
    }
    
    var animationDuration: TimeInterval = 5.0
    var animationBeginTime: TimeInterval?
    var gradientColors: [UIColor] = [#colorLiteral(red: 0.6117647059, green: 0.1529411765, blue: 0.6901960784, alpha: 1), #colorLiteral(red: 1, green: 0.2509803922, blue: 0.5058823529, alpha: 1), #colorLiteral(red: 0.4823529412, green: 0.1215686275, blue: 0.6352941176, alpha: 1), #colorLiteral(red: 0.1254901961, green: 0.2980392157, blue: 1, alpha: 1), #colorLiteral(red: 0.1254901961, green: 0.6196078431, blue: 1, alpha: 1), #colorLiteral(red: 0.3529411765, green: 0.4705882353, blue: 0.4980392157, alpha: 1), #colorLiteral(red: 0.2274509804, green: 1, blue: 0.8509803922, alpha: 1)]
    
    private var currentGradient: Int = 0
    
    override init() {
        super.init()
        startPoint = CGPoint(x: 0.0, y: 1.0)
        endPoint = CGPoint(x: 1.0, y: 0.0)
    }
    
    override init(layer: Any) {
        super.init(layer: layer)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    func startAnimation() {
        removeAllAnimations()
        setup()
        animateGradient()
    }
    
    private func currentGradientSet() -> [CGColor] {
        guard gradientColors.count > 0 else { return [] }
        return [gradientColors[currentGradient % gradientColors.count].cgColor,
                gradientColors[(currentGradient + 1) % gradientColors.count].cgColor]
    }
    
    private func setup() {
        colors = currentGradientSet()
        drawsAsynchronously = true
    }
    
    func animateGradient() {
        currentGradient += 1
        let animation = CABasicAnimation(keyPath: Animation.keyPath)
        animation.duration = animationDuration
        if let time = animationBeginTime {
            animation.beginTime = time
        }
        animation.toValue = currentGradientSet()
        animation.fillMode = .forwards
        animation.isRemovedOnCompletion = false
        animation.delegate = self
        add(animation, forKey: Animation.key)
    }
    
    override func removeFromSuperlayer() {
        removeAllAnimations()
        super.removeFromSuperlayer()
    }
    
    func animationDidStop(_ anim: CAAnimation, finished flag: Bool) {
        if flag {
            colors = currentGradientSet()
            animateGradient()
        }
    }
}

I find this subclass to be incredibly useful for my purposes, I suggest that we add this subclass to the project, and then PastelView will be a simple wrapper around this subclass. In fact, PastelView can use PastelLayer as its layerClass which would allow PastelView to interact with auto layout (although, I never tested it, but it should work just fine).

class PastelView: UIView {
    override static var layerClass: AnyClass {
        return PastelLayer.self
    }
}

Downside of this approach is that PastelView would become a simple wrapper around PastelLayer and will have a lot of computed variables and functions that will just call similar function on PastelLayer, e.g.

class PastelView: UIView {
    var endPoint: CGPoint {
        set {
            gradientLayer.endPoint = endPoint
        } get {
            return gradientLayer.endPoint
        }
    }
    
    private var gradientLayer: PastelLayer {
        return layer as! PastelLayer
    }
}

Anyway, I find this addition to be useful when working with CoreAnimation directly, and if you find this idea useful, I will be more than happy to make a PR.

I changed the access control from public to open in order to inherit and pre-set property values ​​inside.

ex)

class CustomPastelView: PastelView {
...
   func initialize() {
// Custom Direction
    startPoint = .bottomLeft
    endPoint = .topRight

    // Custom Duration
    animationDuration = 3.0

    // Custom Color
    setColors(colors: [UIColor(red: 156/255, green: 39/255, blue: 176/255, alpha: 1.0),
                                  UIColor(red: 255/255, green: 64/255, blue: 129/255, alpha: 1.0),
                                  UIColor(red: 123/255, green: 31/255, blue: 162/255, alpha: 1.0),
                                  UIColor(red: 32/255, green: 76/255, blue: 255/255, alpha: 1.0),
                                  UIColor(red: 32/255, green: 158/255, blue: 255/255, alpha: 1.0),
                                  UIColor(red: 90/255, green: 120/255, blue: 127/255, alpha: 1.0),
                                  UIColor(red: 58/255, green: 255/255, blue: 217/255, alpha: 1.0)])
  }
}

Currently PastelView is not fully objc compatible because of the Point enum.

I made several changes to make it compatible and maintain the full original functionality:

• Point enum renamed to PastelPoint and custom case with associated type removed.

• startPoint and endPoint properties are now CGPoint allowing for setting custom points without enum

• Added startPastelPoint and endPastelPoint properties to PastelView which will set the startPoint and endPoint CGPoint properties from their didSet methods.

• Changed method definition for setColors and addColor for better readability when using. *not needed for the objc support.

• Changed code in Readme to reflect changes.

With these changes, PastelView is fully usable in objc out of the box.

Also list Carthage as an installation option in the README.

I think its better to just have the Carthage and Podfile examples there for the user to Cut & Paste.

How does it look?

from https://webgradients.com/

case winterNeva
case dustyGrass
case temptingAzure
case heavyRain
case amyCrisp
case meanFruit
case deepBlue
case ripeMalinka
case cloudyKnoxville
case malibuBeach
case newLife
case trueSunset
case morpheusDen
case rareWind
case nearMoon
case wildApple
case saintPeterburg
case ariellesSmile
case plumPlate
case everlastingSky
case happyFisher

For those who are still having these issues, and looking for an approach to it, I highly recommend using Hero for the transition between view controllers instead of the default one.

From the Hero documentation

"It won't modify any of your views' states other than hiding them during the animation,"

which really suitable for our case here since the previous view's just hiding, thus the transition doesn't interrupt the animation of the gradients at all.

You can find HERO library through this link: https://github.com/HeroTransitions/Hero

Happy coding everyone : )

My controller includes a ImagePickerController, as soon as that displays, the background stops animating. Any ideas why? and how can i make it move again when the imagePicker dismisses

Environment

Xcode 10 + Swift 4.2

Carthage command:

carthage update Pastel --platform ios --no-use-binaries

Build output

Build Failed Task failed with exit code 65: /usr/bin/xcrun xcodebuild -project /Users/lvjun/Desktop/StarOrder3-iOS/Carthage/Checkouts/Pastel/Pastel.xcodeproj -scheme Pastel -configuration Release -derivedDataPath /Users/lvjun/Library/Caches/org.carthage.CarthageKit/DerivedData/10.1_10B61/Pastel/0.5.1 -sdk iphoneos ONLY_ACTIVE_ARCH=NO CODE_SIGNING_REQUIRED=NO CODE_SIGN_IDENTITY= CARTHAGE=YES archive -archivePath /var/folders/hl/__r3qrxd5_168lfx7v85xf3c0000gn/T/Pastel SKIP_INSTALL=YES GCC_INSTRUMENT_PROGRAM_FLOW_ARCS=NO CLANG_ENABLE_CODE_COVERAGE=NO STRIP_INSTALLED_PRODUCT=NO (launched in /Users/lvjun/Desktop/StarOrder3-iOS/Carthage/Checkouts/Pastel)

This usually indicates that project itself failed to compile. Please check the xcodebuild log for more details: /var/folders/hl/__r3qrxd5_168lfx7v85xf3c0000gn/T/carthage-xcodebuild.c9ufBT.log

I have a button in my app which has a "random gradient" functionality.

How can I remove any existing gradient on the screen and replace it with a new one?

I don't see any functionality in the api code which will allow us to set new gradients without removing the entire view and re-adding it to the screen.