Custom CALayerAnimation

CustomLayerAnimation.m

@implementation CustomAnimationLayer

@dynamic changingProperty1, changingProperty2;

-(CABasicAnimation *)makeAnimationForKey:(NSString *)key {
	CABasicAnimation *anim = [CABasicAnimation animationWithKeyPath:key];
	anim.fromValue = [[self presentationLayer] valueForKey:key];
	anim.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
	anim.duration = kSomeDuration;
	return anim;
}

-(id<CAAction>)actionForKey:(NSString *)event {
	if ([event isEqualToString:@"changingProperty1"] ||
		[event isEqualToString:@"changingProperty2"]) {
		return [self makeAnimationForKey:event];
	}
	
	return [super actionForKey:event];
}

- (id)initWithLayer:(id)layer {
	if (self = [super initWithLayer:layer]) {
		//copy layer property to self here
	}
	
	return self;
}

+ (BOOL)needsDisplayForKey:(NSString *)key {
	if ([key isEqualToString:@"changingProperty1"] || [key isEqualToString:@"changingProperty2"]) {
		return YES;
	}
	
	return [super needsDisplayForKey:key];
}


-(void)drawInContext:(CGContextRef)ctx {
	// Update Context here
}
@end