Is it possible to snap UIViews using UISnapBehavior consecutively - ios

Question

I am working on CS193P and I would like to create an effect where cards fly in from the 0,0 one after another snapping into place. I tried to chain the animation but the views flying together also I am trying to use UIDynamicAnimator and same thing happens. All the views are snapping together. Here is the code that i have to snap the views.
-(void)snapCardsForNewGame
{
for (PlayingCardView *cardView in self.cards){
NSUInteger cardViewIndex = [self.cards indexOfObject:cardView];
int cardColumn = (int) cardViewIndex / self.gameCardsGrid.rowCount;
int cardRow = (int) cardViewIndex % self.gameCardsGrid.rowCount;
UISnapBehavior *snapCard = [[UISnapBehavior alloc]initWithItem:cardView snapToPoint:[self.gameCardsGrid centerOfCellAtRow:cardRow inColumn:cardColumn]];
snapCard.damping = 1.0;
[self.animator addBehavior:snapCard];
}
}
-(void)newGame
{
NSUInteger numberOfCardsInPlay = [self.game numberOfCardsInPlay];
for (int i=0; i<numberOfCardsInPlay; i++) {
PlayingCardView *playingCard = [[PlayingCardView alloc]initWithFrame:CGRectMake(0, 0, 50, 75)];
playingCard.faceUp = YES;
[playingCard addGestureRecognizer:[[UITapGestureRecognizer alloc]initWithTarget:self action:#selector(flipCard:)]];
[self.cards addObject:playingCard];
//NSUInteger cardViewIndex = [self.cards indexOfObject:playingCard];
//int cardColumn = (int) cardViewIndex / self.gameCardsGrid.rowCount;
//int cardRow = (int) cardViewIndex % self.gameCardsGrid.rowCount;
// playingCard.frame = [self.gameCardsGrid frameOfCellAtRow:cardRow inColumn:cardColumn];
playingCard.center = CGPointMake(0, 0);
[self.gameView addSubview:playingCard];
[self snapCardsForNewGame];
}
}
Does it even make sense to use it in this situation? I tried few different things to get the cards fly in one by one but wasn't able to.
Thanks in advance!

Answer 1

Since you're adding all the UISnapBehaviors at the same time, the animator runs them all together. Delay adding them to the animator and they'll be animated on their own.
-(void)snapCardsForNewGame
{
for (PlayingCardView *cardView in self.cards){
NSUInteger cardViewIndex = [self.cards indexOfObject:cardView];
int cardColumn = (int) cardViewIndex / self.gameCardsGrid.rowCount;
int cardRow = (int) cardViewIndex % self.gameCardsGrid.rowCount;
UISnapBehavior *snapCard = [[UISnapBehavior alloc]initWithItem:cardView snapToPoint:[self.gameCardsGrid centerOfCellAtRow:cardRow inColumn:cardColumn]];
snapCard.damping = 1.0;
NSTimeInterval delayTime = 0.01 * cardViewIndex;
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayTime * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
[self.animator addBehavior:snapCard];
});
}
}