CODEWITHSUNDEEP
iosobjective-ccocoa-touchuiviewuilabel
Abhinav
Abhinav

Reputation: 38162

Blinking effect on UILabel

I have a UILabel with background color as grey.

I want a blinking effect on this label like it should become a little white & then become gray and it should keep happen till I turn it off programatically.

Any clue how to achieve this?

Upvotes: 28

Views: 39983

Answers (14)

Abhishek Bedi
Abhishek Bedi

Reputation: 5451

A different approach but works. Blinking only for 3 seconds

extension UIView {
  func blink() {
    let animation = CABasicAnimation(keyPath: "opacity")
    animation.isRemovedOnCompletion = false
    animation.fromValue           = 1
    animation.toValue             = 0
    animation.duration            = 0.8
    animation.autoreverses        = true
    animation.repeatCount         = 3
    animation.beginTime           = CACurrentMediaTime() + 0.5
    self.layer.add(animation, forKey: nil)
    }
}

Upvotes: 6

DavidS
DavidS

Reputation: 520

Got stuck when trying with swift and using multiple options but this seems to work nicely:

self.cursorLabel.alpha = 1
UIView.animate(withDuration: 0.7, delay: 0.0, options: [.repeat, .autoreverse, .curveEaseInOut], animations: {
    self.cursorLabel.alpha = 0
}, completion: nil)

Upvotes: 2

biomiker
biomiker

Reputation: 3306

For Swift 3+, building on all the great answers here, I ended up with a few tweaks that gave me smooth blinking effect that automatically stops after a given number of cycles. 

extension UIView {
    func blink(duration: Double=0.5, repeatCount: Int=2) {
        self.alpha = 0.0;
        UIView.animate(withDuration: duration,
            delay: 0.0,
            options: [.curveEaseInOut, .autoreverse, .repeat],
            animations: { [weak self] in
                UIView.setAnimationRepeatCount(Float(repeatCount) + 0.5)
                self?.alpha = 1.0
            }
        )
    }
}

Upvotes: 0

tiguero
tiguero

Reputation: 11537

You can simply make an extension to the UILabel class that will support the blinking effect. I don't think using a timer is a right approach since you won't have any fade effect.

Here is the Swift way to do this:

extension UILabel {
    func blink() {
        self.alpha = 0.0;
        UIView.animateWithDuration(0.8, //Time duration you want,
                            delay: 0.0,
                          options: [.CurveEaseInOut, .Autoreverse, .Repeat],
                       animations: { [weak self] in self?.alpha = 1.0 },
                       completion: { [weak self] _ in self?.alpha = 0.0 })
    }
}

Swift 3:

extension UILabel {
    func blink() {
        self.alpha = 0.0;
        UIView.animate(withDuration: 0.8, //Time duration you want,
            delay: 0.0,
            options: [.curveEaseInOut, .autoreverse, .repeat],
            animations: { [weak self] in self?.alpha = 1.0 },
            completion: { [weak self] _ in self?.alpha = 0.0 })
    }
}

EDIT Swift 3: Works for almost any view

extension UIView {
    func blink() {
        self.alpha = 0.0;
        UIView.animate(withDuration: 0.8, //Time duration you want,
            delay: 0.0,
            options: [.curveEaseInOut, .autoreverse, .repeat],
            animations: { [weak self] in self?.alpha = 1.0 },
            completion: { [weak self] _ in self?.alpha = 0.0 })
    }
}

Upvotes: 23

Erik Peruzzi
Erik Peruzzi

Reputation: 535

Here is my solution in Swift 4.0 with extension for any UIVIew 

extension UIView{
    func blink() {
        self.alpha = 0.2

        UIView.animate(withDuration: 1,
                                   delay: 0.0,
                                   options: [.curveLinear,
                                             .repeat,
                                             .autoreverse],
                                   animations: { self.alpha = 1.0 },
                                   completion: nil)   
    }
}

Upvotes: 0

Jaseem Abbas
Jaseem Abbas

Reputation: 5230

Swift 3

extension UILabel {

    func startBlink() {
        UIView.animate(withDuration: 0.8,
              delay:0.0,
              options:[.allowUserInteraction, .curveEaseInOut, .autoreverse, .repeat],
              animations: { self.alpha = 0 }, 
              completion: nil)
    }

    func stopBlink() {
        layer.removeAllAnimations()
        alpha = 1
    }
}

Upvotes: 34

Flex Elektro Deimling
Flex Elektro Deimling

Reputation: 1619

You can do this within a block:

self.yourLabel.alpha = 1;
[UIView animateWithDuration:1.5 delay:0.5 options:UIViewAnimationOptionRepeat | UIViewAnimationOptionAutoreverse animations:^{
        self.yourLabel.alpha = 0;
} completion:nil];

So you dont need a second method.

Upvotes: 57

SoftDesigner
SoftDesigner

Reputation: 5853

My swift version based on Flex Elektro Deimling's answer:

private func startTimeBlinkAnimation(start: Bool) {
    if start {
        timeContainerView.alpha = 1
        UIView.animateWithDuration(0.6, delay: 0.3, options:[.Repeat, .Autoreverse], animations: { _ in
            self.timeContainerView.alpha = 0
        }, completion: nil)
    }
    else {
        timeContainerView.alpha = 1
        timeContainerView.layer.removeAllAnimations()
    }
}

Upvotes: 2

Edilson Junior
Edilson Junior

Reputation: 19

This is how it worked for me. I adapted the answer of @flex_elektro_deimling

First parameter UIView.animateWithDuration is the total time of the animation (In my case I've set it to 0.5), you may set different values on the first and second (delay) to change the blinking speed. 

    self.YOURLABEL.alpha = 0;
    UIView.animateWithDuration(
        0.5, 
        delay: 0.2, 
        options: UIViewAnimationOptions.Repeat | UIViewAnimationOptions.Autoreverse, animations: {
            self.YOURLABEL.alpha = 1
        },
        completion:nil)

Upvotes: 1

Alessandro Ornano
Alessandro Ornano

Reputation: 35392

-(void) startBlinkingLabel:(UILabel *)label 
{
    label.alpha =1.0f;
    [UIView animateWithDuration:0.32
                          delay:0.0
                        options: UIViewAnimationOptionAutoreverse |UIViewAnimationOptionRepeat | UIViewAnimationOptionCurveEaseInOut | UIViewAnimationOptionAllowUserInteraction |UIViewAnimationOptionBeginFromCurrentState
                     animations:^{
                         label.alpha = 0.0f;
                     }
                     completion:^(BOOL finished){
                         if (finished) {

                         }
                     }];
}

-(void) stopBlinkingLabel:(UILabel *)label 
{
    // REMOVE ANIMATION
    [label.layer removeAnimationForKey:@"opacity"];
    label.alpha = 1.0f;
}

Upvotes: 2

Baljeet Singh
Baljeet Singh

Reputation: 453

    int count;
    NSTimer *timer;

      timer= [NSTimer
                  scheduledTimerWithTimeInterval:(NSTimeInterval)(0.5)
                  target:self
                  selector:@selector(animationStart)
                  userInfo:nil
                  repeats:TRUE];

-(void)animationStart{
switch (count) {
    case 0:
        //205   198 115
        count++;
        lbl.textColor=[UIColor colorWithRed:205.0f/255.0f green:198.0f/255.0f blue:115.0f/255.0f alpha:1];

        break;
    case 1:
         count++;
        //205   198 115 56  142 142
        lbl.textColor=[UIColor colorWithRed:56.0f/255.0f green:142.0f/255.0f blue:142.0f/255.0f alpha:1];

        break;
    case 2:
         count++;
        //205   198 115
        lbl.textColor=[UIColor colorWithRed:205.0f/255.0f green:205.0f/255.0f blue:0.0f/255.0f alpha:1];

        break;
    case 3:
         count++;
        //205   198 115 84  255 159
        lbl.textColor=[UIColor colorWithRed:84.0f/255.0f green:255.0f/255.0f blue:159.0f/255.0f alpha:1];

        break;
    case 4:
         count++;
        //205   198 115 255 193 37
        lbl.textColor=[UIColor colorWithRed:255.0f/255.0f green:193.0f/255.0f blue:37.0f/255.0f alpha:1];

        break;
    case 5:
         count++;
        //205   198 115 205 200 177
        lbl.textColor=[UIColor colorWithRed:205.0f/255.0f green:200.0f/255.0f blue:117.0f/255.0f alpha:1];

        break;
    case 6:
         count++;
        //205   198 115 255 228 181
        lbl.textColor=[UIColor colorWithRed:255.0f/255.0f green:228.0f/255.0f blue:181.0f/255.0f alpha:1];

        break;
    case 7:
         count++;
        //205   198 115 233 150 122
        lbl.textColor=[UIColor colorWithRed:233.0f/255.0f green:150.0f/255.0f blue:122.0f/255.0f alpha:1];

        break;
    case 8:
        count++;
        //205   198 115 233 150 122
        lbl.textColor=[UIColor colorWithRed:255.0f/255.0f green:200.0f/255.0f blue:200.0f/255.0f alpha:1];

        break;
    case 9:
         count=0;
        //205   198 115 255 99  71 255  48  48
        lbl.textColor=[UIColor colorWithRed:255.0f/255.0f green:48.0f/255.0f blue:48.0f/255.0f alpha:1];

        break;

    default:
        break;
}

}

Upvotes: 0

Chris
Chris

Reputation: 4593

Rather use the view animations. It makes it very simple and is easy to control. Try this:

self.yourLabel.alpha = 1.0f;
[UIView animateWithDuration:0.12
  delay:0.0
  options:UIViewAnimationOptionCurveEaseInOut | 
          UIViewAnimationOptionRepeat | 
          UIViewAnimationOptionAutoreverse | 
          UIViewAnimationOptionAllowUserInteraction
  animations:^{
   self.yourLabel.alpha = 0.0f;
}
completion:^(BOOL finished){
// Do nothing
}];

You can tweak the values to get different effects for example, changing animateWithDuration wil set the blinking speed. Further you can use it on anything that inherits from UIView example a button, label, custom view etc.

Upvotes: 3

Krishnabhadra
Krishnabhadra

Reputation: 34275

Use NSTimer 

NSTimer *timer = [NSTimer 
                      scheduledTimerWithTimeInterval:(NSTimeInterval)(1.0)
                            target:self 
                             selector:@selector(blink) 
                             userInfo:nil 
                             repeats:TRUE];
BOOL blinkStatus = NO;

in your blink function

-(void)blink{
   if(blinkStatus == NO){
      yourLabel.backgroundColor = [UIColor whiteColor];
     blinkStatus = YES;
   }else {
      yourLabel.backgroundColor = [UIColor grayColor];
      blinkStatus = NO;
   }
}

Upvotes: 22

Just Variable
Just Variable

Reputation: 877

Tweaking Krishnabhadra Answer to give a better blink effect

Declare a Class variable bool blinkStatus;

And paste code given below

NSTimer *yourtimer = [NSTimer scheduledTimerWithTimeInterval:(NSTimeInterval)(10.0 / 60.0)  target:self selector:@selector(blink) userInfo:nil repeats:TRUE];
    blinkStatus = FALSE;

-(void)blink{
    if(blinkStatus == FALSE){
        yourLabel.hidden=NO;
        blinkStatus = TRUE;
    }else {
        yourLabel.hidden=YES;
        blinkStatus = FALSE;
    }
}

Upvotes: 2

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