Quickly Build an Input-Driven Game - Beginning iOS6 Games Development - page 86

Listing 4-22. CoinsController.m (stopCoinAt:)
-(void)stopCoinAt:(Coord)coord{
UIImageView* coinView = [[coinsView subviews] objectAtIndex:[coinsGame indexForCoord:coord]];
NSNumber* coin = [coinsGame coinForCoord:coord];
UIImage* image = imageForCoin([coin intValue]);
[coinView stopAnimating];
[coinView setImage: image];
}
The task stopCoinAt: takes the coordinate of the coin to stop spinning. This is done by first finding
the appropriate UIImageView representing the coin to be stopped, called coinView . We stop the
spinning animation by calling stopAnimation: , but we don't want to just stop it, we want to display
the face of the coin. We can find the correct image to use by first calling coinForCoord in coinsGame
to figure out the type of coin it is and then calling imageForCoin to return the UIImage we want to
use. We simply call setImage on coinView and pass in the UIImage named image . The function
imageForCoin simply returns a UIImage based on the int that is passed in, as shown in Listing 4-23.
Listing 4-23. CoinsController.m (imageForCoin(int))
UIImage* imageForCoin(int coin){
if (coin == COIN_TRIANGLE){
return [UIImage imageNamed:@"coin_triangle0001"];
} else if (coin == COIN_SQUARE){
return [UIImage imageNamed:@"coin_square0001"];
} else if (coin == COIN_CIRCLE){
return [UIImage imageNamed:@"coin_circle0001"];
}
return nil;
}
In Listing 4-24, we see the code that is executed when a coin was previously selected.
Listing 4-24. CoinsController.m (tapGesture:, continued)
if (CoordEqual(firstSelectedCoin, coinCoord)){//re selected the first one.
isFirstCoinSelected = false;
[self spinCoinAt:firstSelectedCoin];
} else {//selected another one, do switch.
acceptingInput = false;
[coinsGame setRemaingTurns: [coinsGame remaingTurns] - 1];
[delegate turnsRemainingDecreased:self with: [coinsGame remaingTurns]];
isFirstCoinSelected = false;
secondSelectedCoin = coinCoord;
[self stopCoinAt:secondSelectedCoin];
[self doSwitch:firstSelectedCoin With:secondSelectedCoin];
}