Restart animation when comes back in foreground - ios

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.

Answer 1

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];
}

Answer 2

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];
}

Answer 3

You should read Looking to understand the iOS UIViewController lifecycle carefully.
The methods your are looking to use are
viewWillAppear and viewWillDisappear

Answer 4

-(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];
}];
}];
}];
}];
}];
}];
}];
}];
}

Answer 5

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