how to play sequential animations infinitely? - uiview

Question

I have a series of animations that are supposed to trigger one after another with delays. The code that i used works fine but i want all the views that i am animating to animate in a circle infinitely.
this is the code:
[UIView animateWithDuration:2.0
delay:2.0
options: UIViewAnimationOptionTransitionNone
animations:^{
carouselTextView.frame=CGRectMake(-320, 200, 1600, 150);
}
completion:^(BOOL finished){
{
[UIView animateWithDuration:2.0
delay:2.0
options: UIViewAnimationOptionTransitionNone
animations:^{
carouselTextView.frame=CGRectMake(-640, 200, 1600, 150);
}
completion:^(BOOL finished){
{
[UIView animateWithDuration:2.0
delay:2.0
options: UIViewAnimationOptionTransitionNone
animations:^{
carouselTextView.frame=CGRectMake(-960, 200, 1600, 150);
}
completion:^(BOOL finished){
[UIView animateWithDuration:2.0
delay:2.0
options: UIViewAnimationOptionTransitionNone
animations:^{
carouselTextView.frame=CGRectMake(-1280, 200, 1600, 150);
}
completion:^(BOOL finished){
}]; }];
};
}];
};
}];

Answer 1

You are not supposed to write all the animation again from the beginning in the completion part, easily all that you need to do is to run the method again, code below:
completion:^(BOOL finished){
[self methodYouNamed];
}
Write that code in the completion part, the syntax here is simple, it says **whenever your animation is finished, run the method again, this will not end and will continue forever as you want **

Answer 2

OK, I'll help then. Firstly you need to discern the variable parts of the animation sequence from the constant parts. Provide some sort of data store of the variable parts and cycle through them using a method.
So looking at the code, all I can see that varies is this bit:
carouselTextView.frame=CGRectMake(...);
(note all this code is within your class's implementation file).
So lets store those in a static array (it's static as I assume the values never change, however if they could change then they will need to be an instance variable of the class):
static CGRect _carouselTextViewFrames[] = {
{-320, 200, 1600, 150},
{-640, 200, 1600, 150},
{-960, 200, 1600, 150},
{-1280, 200, 1600, 150}
};
const NSInteger NUM_CAROUSEL_TEXT_FIELD_FRAMES = sizeof(_carouselTextViewFrames) / sizeof(_carouselTextViewFrames[0]);
Next we need to track the current carousel text view frame (an index into _carouselTextViewFrames[]). This must be an instance variable:
#interface YourClass ()
// private property
#property (nonatomic, assign) NSInteger carouselTextViewFrameIndex;
#end
and this must be initialized to -1 so the first index used is 0 (see nextCarouselAnimation, below):
- (id)init { // Or whatever designated initializer is used in your class
self = [super init];
if (self) {
self.carouselTextViewFrameIndex = -1;
}
return self;
}
Now the method that will start the next animation:
- (void)nextCarouselAnimation {
self.carouselTextViewFrameIndex = (self.carouselTextViewFrameIndex + 1) % NUM_CAROUSEL_TEXT_FIELD_FRAMES;
[UIView animateWithDuration:2.0
delay:2.0
options:UIViewAnimationOptionTransitionNone
animations:^{
carouselTextView.frame = _carouselTextViewFrames[self.carouselTextViewFrameIndex];
}
completion:^(BOOL finished){
[self nextCarouselAnimation];
}];
}
And finally you just need to start the animation cycle going by calling nextCarouselAnimation from somewhere appropriate (you don't say what your class is derived from, so I don't know where that might be).
NOTE: This code is untested and likely contains numerous mistakes.