Visual Effects - iOS Core Animation - page 65

@end
@implementation ViewController
- ( void )viewDidLoad
{
[ super viewDidLoad ];
//get spritesheet image
UIImage *digits = [ UIImage imageNamed : @"Digits.png" ];
//set up digit views
for ( UIView *view in self .digitViews)
{
//set contents
view. layer . contents = ( __bridge id )digits. CGImage ;
view. layer . contentsRect = CGRectMake ( 0 , 0 , 0.1 , 1.0 );
view. layer . contentsGravity = kCAGravityResizeAspect ;
}
//start timer
self .timer = [ NSTimer scheduledTimerWithTimeInterval : 1.0
target : self
selector : @selector (tick)
userInfo : nil
repeats : YES ];
//set initial clock time
[ self tick ];
}
- ( void )setDigit:( NSInteger )digit forView:( UIView *)view
{
//adjust contentsRect to select correct digit
view. layer . contentsRect = CGRectMake (digit * 0.1 , 0 , 0.1 , 1.0 );
}
- ( void )tick
{
//convert time to hours, minutes and seconds
NSCalendar *calendar = [[ NSCalendar alloc ] initWithCalendarIdentifier :
NSGregorianCalendar ];
NSUInteger units = NSHourCalendarUnit |
NSMinuteCalendarUnit |
NSSecondCalendarUnit ;