UIImage animationImages tint color?

Question

Is there a way to tint the images in an animation?

I know I can tint a single image like this:

var imageOne:UIImage = UIImage(named: "pullto_1.png")!;
    imageOne = imageOne.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate);
    refSequence.image = imageOne;

But when I try to do it like this it just dosen't work:

 var imageOne:UIImage = UIImage(named: "pullto_1.png")!;
    imageOne = imageOne.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate)

    var image2:UIImage = UIImage(named: "pullto_2.png")!;
    image2 = image2.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate)

    var image3:UIImage = UIImage(named: "pullto_3.png")!;
    image3 = image3.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate)

    var image4:UIImage = UIImage(named: "pullto_4.png")!;
    image4 = image4.imageWithRenderingMode(UIImageRenderingMode.AlwaysTemplate)

    refSequence.animationImages = NSArray(objects: imageOne,
        image2,
        image3,
        image4

    );

    refSequence.animationDuration = 1.4;
    refSequence.animationRepeatCount = 99;
    refSequence.startAnimating();

Am I doing something wrong? Is there some way to tint the images in the animation?

Thanks

Answer 1

Ok, i hoped that there is a simpler solution but this is what I ended up doing:

This function will create a new image with the wanted color:

func imageWithColor(img:UIImage, color:UIColor)->UIImage{
    UIGraphicsBeginImageContextWithOptions(img.size, false, img.scale);
    var context = UIGraphicsGetCurrentContext();
    CGContextTranslateCTM(context, 0, img.size.height);
    CGContextScaleCTM(context, 1.0, -1.0);
    CGContextSetBlendMode(context, kCGBlendModeNormal);
    var rect = CGRectMake(0, 0, img.size.width, img.size.height);
    CGContextClipToMask(context, rect, img.CGImage)
    color.setFill();
    CGContextFillRect(context, rect);
    var newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return newImage;
}

And then you can call it like this:

var imageOne:UIImage = UIImage(named: "pullto_1.png")!;
    imageOne = imageWithColor(imageOne, color: UIColor.redColor());
    var image2:UIImage = UIImage(named: "pullto_2.png")!;
    image2 = imageWithColor(image2, color: UIColor.redColor());
    var image3:UIImage = UIImage(named: "pullto_3.png")!;
    image3 = imageWithColor(image3, color: UIColor.redColor());
    var image4:UIImage = UIImage(named: "pullto_4.png")!;
    image4 = imageWithColor(image4, color: UIColor.redColor());

    loaderS.animationImages = NSArray(objects: imageOne,
        image2,
        image3,
        image4

    );



    loaderS.animationDuration = 1.4;
    loaderS.animationRepeatCount = 99;
    loaderS.startAnimating();

Answer 2

Here is a handy UIImage extension:

import UIKit

extension UIImage {

    func imageWithTint(tint: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(size, false, scale)
        let context = UIGraphicsGetCurrentContext()
        CGContextTranslateCTM(context, 0, size.height)
        CGContextScaleCTM(context, 1.0, -1.0)
        CGContextSetBlendMode(context, .Normal)
        let rect = CGRect(origin: .zero, size: size)
        CGContextClipToMask(context, rect, CGImage)
        tint.setFill()
        CGContextFillRect(context, rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image;
    }

}

Answer 3

There's a rdar about this issue ( http://www.openradar.me/23517334 ) and the problem still persists on iOS 11.

I adapted the code examples above to Swift 4.

extension UIImage {
    func image(withTintColor color: UIColor) -> UIImage {
        UIGraphicsBeginImageContextWithOptions(size, false, scale)

        let context = UIGraphicsGetCurrentContext()
        context?.translateBy(x: 0, y: size.height)
        context?.scaleBy(x: 1.0, y: -1.0)
        context?.setBlendMode(.normal)

        let rect = CGRect(origin: .zero, size: size)
        context?.clip(to: rect, mask: cgImage!)
        color.setFill()
        context?.fill(rect)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()

        return image!
    }
}

Answer 4

Here's updated code for Swift 4 with a few safety checks.

extension UIImage {
    func image(withTint tint: UIColor) -> UIImage? {
        guard let cgImage = cgImage else {
            return nil
        }

        UIGraphicsBeginImageContextWithOptions(size, false, scale)
        guard let context = UIGraphicsGetCurrentContext() else {
            return nil
        }

        let rect = CGRect(origin: .zero, size: size)

        context.translateBy(x: 0, y: size.height)
        context.scaleBy(x: 1.0, y: -1.0)
        context.setBlendMode(.normal)
        context.clip(to: rect, mask: cgImage)
        tint.setFill()
        context.fill(rect)

        let image = UIGraphicsGetImageFromCurrentImageContext()!
        UIGraphicsEndImageContext()
        return image
    }
}

Answer 5

Maybe this example extension helps:

 extension UIImageView {

        func pulsingTintColor() {
            UIView.animate(withDuration: 2, delay: 0.0, options: [.repeat, .autoreverse], animations: {
                         self.tintColor = UIColor.red
                         self.tintColor = UIColor.green
                         self.tintColor = UIColor.blue
            }, completion: nil)
        }
    }

Ensure you have set the Render as: Template Image option in your asset catalog. This works for UIViews as well. Just replace tintColor with backgroundColor .

If you need parametrised colours:

func pulsingTintColor(with colors: [UIColor] = [UIColor.red, UIColor.green, UIColor.blue]) {
    UIView.animate(withDuration: 2, delay: 0.0, options: [.repeat, .autoreverse], animations: {
         colors.forEach({self.tintColor = $0})
    }, completion: nil)
}