Adding glow effect to UIButton - iOS

Swift 5

1. Create UIView extension with the animation

2. Use it on textfields, buttons, views (any subclass of UIView)

Note: you may change values and play around to get the effect you need.

UIView extension

import UIKit

extension UIView {
    enum GlowEffect: Float {
        case small = 0.4, normal = 2, big = 15
    }

    func doGlowAnimation(withColor color: UIColor, withEffect effect: GlowEffect = .normal) {
        layer.masksToBounds = false
        layer.shadowColor = color.cgColor
        layer.shadowRadius = .zero
        layer.shadowOpacity = 1
        layer.shadowOffset = .zero
    
        let glowAnimation = CABasicAnimation(keyPath: "shadowRadius")
        glowAnimation.fromValue = Int.zero
        glowAnimation.toValue = effect.rawValue
        glowAnimation.beginTime = CACurrentMediaTime()+0.3
        glowAnimation.duration = CFTimeInterval(0.3)
        glowAnimation.fillMode = .removed
        glowAnimation.autoreverses = true
        glowAnimation.isRemovedOnCompletion = true
        layer.add(glowAnimation, forKey: "shadowGlowingAnimation")
    }
}

How to use it:

//TextField with border
textField.doGlowAnimation(withColor: UIColor.red, withEffect: .big)

//Label
label.doGlowAnimation(withColor: label.textColor, withEffect: .small)

//Button
button.doGlowAnimation(withColor: UIColor.red, withEffect: .big)

I like this glow + grow/shrink animation for my 'extra special' buttons:

-(void)makeViewShine:(UIView*) view
{
view.layer.shadowColor = [UIColor yellowColor].CGColor;
view.layer.shadowRadius = 10.0f;
view.layer.shadowOpacity = 1.0f;
view.layer.shadowOffset = CGSizeZero;


[UIView animateWithDuration:0.7f delay:0 options:UIViewAnimationOptionAutoreverse | UIViewAnimationCurveEaseInOut | UIViewAnimationOptionRepeat | UIViewAnimationOptionAllowUserInteraction  animations:^{

    [UIView setAnimationRepeatCount:15];

    view.transform = CGAffineTransformMakeScale(1.2f, 1.2f);


} completion:^(BOOL finished) {

    view.layer.shadowRadius = 0.0f;
    view.transform = CGAffineTransformMakeScale(1.0f, 1.0f);
}];

}

I suggest you use the Glow Category of UIView made by secret lab.

Example is available here

Glowing code taken from: Creating a Glow Effect for UILabel and UIButton

First, you'll need to import the QuartzCore Framework:

#import <QuartzCore/QuartzCore.h>

When you create a button (or in viewDidLoad, depends on your code structure) add this code:

UIColor *color = button.currentTitleColor;
button.titleLabel.layer.shadowColor = [color CGColor];
button.titleLabel.layer.shadowRadius = 4.0f;
button.titleLabel.layer.shadowOpacity = .9;
button.titleLabel.layer.shadowOffset = CGSizeZero;
button.titleLabel.layer.masksToBounds = NO;

You'll need to watch for two events: UIControlEventTouchDown and UIControlEventTouchUpInside

In UIControlEventTouchDown handler you'll add the code:

UIColor *color = [UIColor clearColor];
button.titleLabel.layer.shadowColor = [color CGColor];

And in UIControlEventUpInside handler you'll add the code:

UIColor *color = button.currentTitleColor;
button.titleLabel.layer.shadowColor = [color CGColor];

Again details of implementation depend on whether you create button programmaticaly or via Interface Builder but i'm sure you'll be able to figure this out from here on.

EDIT: for a custom button simply adding the following code should work:

[button setImage:[UIImage imageNamed:@"buttonWithGlow.png"]
        forState:UIControlStateNormal];
[button setImage:[UIImage imageNamed:@"buttonWithNoGlow.png"] 
        forState:UIControlStateHighlighted];