Restart animation when comes back in foreground

Question

So i was trying my hands on animation. I have a UIlabel which i want to fade in on and fade out after certain period. I successfully done it as shown in the first answer with the help of timer.

Animation done as shown in Answer 1

Now i want to restart this animation when my app comes foreground. Problems :- What should i do to restart animations?

I want that when app comes in foreground, UIlabel should act as if this is the first time i am starting animation. Basically remove all animation on UIlabel and do start animation fresh.

i have already give you answer in your first question check it — Himanshu Moradiya, Oct 04 '16 at 06:46
@HimanshuMoradiya When coming in foreground i am handling it with notifications. so i tried to again start it with [NSTimer scheduledTimerWithTimeInterval:0.0 target:self selector:@selector(dooratepLabelAnimation:) userInfo:nil repeats:NO]; but uilabel starts flickering. — Sudhanshu Gupta, Oct 04 '16 at 06:51
when u run app first time , Animation is normal or flickering ? — Jitendra Modi, Oct 04 '16 at 07:13
at first animation is perfect, then i tap home button, then i tap on app icon, app comes back to foreground , flickering starts in uilabel — Sudhanshu Gupta, Oct 04 '16 at 07:17
You just have to call timer method in viewwill appear. It seems that Everytime this method calls and your method calls. Use viewWillappear for that — Jitendra Modi, Oct 04 '16 at 07:23
@Jecky can you also tell me why because it seems when home button is pressed viewillappear is not getting called. Then say i present a viewcontroller then while dismissing that , viewillappear of myviewcontroller is called amd flickering starts again — Sudhanshu Gupta, Oct 04 '16 at 09:11
@SudhanshuGupta Check my answer below. I have tested this in my demo application. If work then vote , if it is not worked then Surely downvote it — Jitendra Modi, Oct 04 '16 at 10:26

Anbu.Karthik · Answer 1 · 2016-10-04T06:56:28.153

2

use like add the following method in your ViewDidLoad

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(myMethod) name:UIApplicationWillEnterForegroundNotification object:nil];

-(void)myMethod
{
 // start the beiging code here
 //[self MyLabelAnimation];
[NSTimer scheduledTimerWithTimeInterval:0.0 target:self selector:@selector(MyLabelAnimation:) userInfo:nil repeats:NO];
}

edited Oct 04 '16 at 06:56

answered Oct 04 '16 at 06:50

Anbu.Karthik

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I changed the code to the answer 1 in link. So i am using timer. Can you look at it too. – Sudhanshu Gupta Oct 04 '16 at 06:53
I did the same thing in my code but the uilabel is flickering when coming back to foreground, that is my worry. I think may be i need to remove animation first or i dont know this thing is making me crazy – Sudhanshu Gupta Oct 04 '16 at 07:02
@SudhanshuGupta - 100 % correct , remove animation first if it is run, – Anbu.Karthik Oct 04 '16 at 07:04
still label is flickering, i am removing animations with [self.mylabel.layer removeallanimations;] – Sudhanshu Gupta Oct 04 '16 at 07:10
@SudhanshuGupta - invalidate the timer also my bro – Anbu.Karthik Oct 04 '16 at 07:10
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/124854/discussion-between-sudhanshu-gupta-and-anbu-karthik). – Sudhanshu Gupta Oct 04 '16 at 07:17

score 1 · Answer 2 · answered Oct 04 '16 at 10:11

You should do like this

@interface ViewController ()
{
    NSTimer *timer;
}
@end
-(void)viewWillAppear:(BOOL)animated

{
    [super viewWillAppear:animated];
   timer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(MyLabelAnimation:) userInfo:nil repeats:NO];
}
- (void)MyLabelAnimation:(NSTimer*) timer1 {
    self->_mylabel.text = @"Hello";
    [UIView animateWithDuration:0.3 animations:^{
        self->_mylabel.alpha = 1.0;
    } completion:^(BOOL finished) {

        [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^{
            self->_mylabel.alpha = 0.0;
        } completion:^(BOOL finished) {

            self->_mylabel.text = @"Text 2";
            [UIView animateWithDuration:0.3 animations:^{
                self->_mylabel.alpha = 1.0;
            } completion:^(BOOL finished) {
                [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^{
                    self->_mylabel.alpha = 0.0;
                } completion:^(BOOL finished) {

                    self->_mylabel.text = @"Text 3";
                    [UIView animateWithDuration:0.3 animations:^{
                        self->_mylabel.alpha = 1.0;
                    } completion:^(BOOL finished) {

                        [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^{
                            self->_mylabel.alpha = 0.0;
                        } completion:^(BOOL finished) {

                            self->_mylabel.text = @"Text 4";
                            [UIView animateWithDuration:0.3 animations:^{
                                self->_mylabel.alpha = 1.0;
                            } completion:^(BOOL finished) {
                                [UIView animateWithDuration:0.0 delay:4.8 options:UIViewAnimationOptionCurveEaseInOut animations:^{
                                    self->_mylabel.alpha = 0.0;
                                } completion:^(BOOL finished) {
                                    [self viewWillAppear:YES];
                                }];
                            }];
                        }];
                    }];
                }];
            }];
        }];
    }];

}

-(void)viewWillDisappear:(BOOL)animated
{
    [timer invalidate];
}

thanks for doing these things .. when i press home button , sometimes the first text is shown , sometimes second. Just try to press home button and app icon to launch very fast , u will also observe the same. — Sudhanshu Gupta, Oct 04 '16 at 10:30
@SudhanshuGupta just make one change Write viewDidAppear instead of viewWillAppear in both place. and observe it — Jitendra Modi, Oct 04 '16 at 10:35
nope its not working , when we press home and return viewwilllappear and didappear are not called — Sudhanshu Gupta, Oct 04 '16 at 10:42
Me any my friend have tried this and working successfully but in your case I am sorry for you. Now I cant help you anymore. Thank you — Jitendra Modi, Oct 04 '16 at 10:44
thanks for your help may be i am doing something wrong from my end — Sudhanshu Gupta, Oct 04 '16 at 10:47
@SudhanshuGupta please give me Email Id I will send my demo build for your query and observe it — Jitendra Modi, Oct 04 '16 at 10:58
Let us [continue this discussion in chat](http://chat.stackoverflow.com/rooms/124900/discussion-between-jecky-and-sudhanshu-gupta). — Jitendra Modi, Oct 04 '16 at 13:19

score 0 · Answer 3 · edited May 23 '17 at 12:34

0

You should read Looking to understand the iOS UIViewController lifecycle carefully.

The methods your are looking to use are

viewWillAppear and viewWillDisappear

edited May 23 '17 at 12:34

Community

1
1

answered Oct 04 '16 at 06:49

Antzi

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1

Who give this post downvote ? This answer is correct. Please I request dont give downvote to certain correct answers – Jitendra Modi Oct 04 '16 at 07:24
No, it's not correct. These methods are not called when an app returns to the foreground. – rmaddy Oct 04 '16 at 15:09

Himanshu Moradiya · Answer 4 · 2016-10-04T07:22:11.640

-(void) viewWillAppear:(BOOL)animated{
    [super viewWillAppear:animated];
      [NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(MyLabelAnimation:) userInfo:nil repeats:NO];
}

// Your animation....

- (void)MyLabelAnimation:(NSTimer*) timer {
    self->mylabel.text = @"Hello";
    [UIView animateWithDuration:0.3 animations:^{
        self->mylabel.alpha = 1.0;
    } completion:^(BOOL finished) {

        [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^{
            self->mylabel.alpha = 0.0;
        } completion:^(BOOL finished) {

            self->mylabel.text = @"Text 2";
            [UIView animateWithDuration:0.3 animations:^{
                self->mylabel.alpha = 1.0;
            } completion:^(BOOL finished) {
                [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^{
                    self->mylabel.alpha = 0.0;
                } completion:^(BOOL finished) {

                    self->mylabel.text = @"Text 3";
                    [UIView animateWithDuration:0.3 animations:^{
                        self->mylabel.alpha = 1.0;
                    } completion:^(BOOL finished) {

                        [UIView animateWithDuration:0.3 delay:2.7 options:UIViewAnimationOptionCurveEaseInOut animations:^{
                            self->mylabel.alpha = 0.0;
                        } completion:^(BOOL finished) {

                            self->mylabel.text = @"Text 4";
                            [UIView animateWithDuration:0.3 animations:^{
                                self->mylabel.alpha = 1.0;
                            } completion:^(BOOL finished) {
                                [UIView animateWithDuration:0.0 delay:4.8 options:UIViewAnimationOptionCurveEaseInOut animations:^{
                                    self->mylabel.alpha = 0.0;
                                } completion:^(BOOL finished) {

                                     [NSTimer scheduledTimerWithTimeInterval:0.0 target:self selector:@selector(MyLabelAnimation:) userInfo:nil repeats:NO];
                                }];
                            }];
                        }];
                    }];
                }];
            }];
        }];
    }];

}

it is still flickering do i need to remove uilabel aniamtions first — Sudhanshu Gupta, Oct 04 '16 at 07:08
one more thing , is it necessay to send a notification, can't we just use timer when coming in foreground — Sudhanshu Gupta, Oct 04 '16 at 07:09
when u run app first time , Animation is normal or flickering ? — Jitendra Modi, Oct 04 '16 at 07:12
@SudhanshuGupta i just edit my answer now its work perfectly i check this all in my demo project u also check now. — Himanshu Moradiya, Oct 04 '16 at 07:22
@HimanshuMoradiya I think viewillappear is not getting called when we preass home button, but lets say i have a present view controller , which i present in this viewcontroller then viewwill appear is getting called and again flickering starts — Sudhanshu Gupta, Oct 04 '16 at 09:07
Its call Brother check it i already done this think so now its your turn just use my code . — Himanshu Moradiya, Oct 04 '16 at 09:08
@HimanshuMoradiya really viewwillappear is not called when we press homebutton and launch again. But flickering will start as i start timer call again — Sudhanshu Gupta, Oct 04 '16 at 09:18
i have use this code and in my demo project is work completely . — Himanshu Moradiya, Oct 04 '16 at 09:20

score 0 · Answer 5 · edited May 23 '17 at 10:30

0

Here is the answer for the question I have asked. Inwit done it with the help of a bool variable which sets to No when app goes in background and will get set to yes when goes in foreground.

SO the next animation depends on the bool value.

Here is the link for the answer Restart animation after pause

edited May 23 '17 at 10:30

Community

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answered Oct 08 '16 at 08:47

Sudhanshu Gupta

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Restart animation when comes back in foreground

5 Answers5