This is one way to animate the filling of a circle in objective-c, does anyone know the right way?

FillCircle.m

//
//  FillCircle.m
//  cramera
//
//  Created by Chris Allick on 1/30/13.
//  Copyright (c) 2013 Chris Allick. All rights reserved.
//

#import "FillCircle.h"

#define RAD2DEG(radians) ((radians) * (180.0 / M_PI))
#define DEG2RAD(angle) ((angle) / 180.0 * M_PI)

@implementation FillCircle {
    float angle;
}

@synthesize checkImageView, checkImage;

- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        angle = 0.0;
        
        checkImage = [UIImage imageNamed:@"close.png"];
        checkImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, self.frame.size.width, self.frame.size.height)];
        [checkImageView setImage:checkImage];

        [NSTimer scheduledTimerWithTimeInterval:.01
                                         target:self
                                       selector:@selector(tick:)
                                       userInfo:nil
                                        repeats:YES];
    }
    return self;
}

- (void) tick:(NSTimer *) timer {
    if( angle < 1.0 ) {
        [self setNeedsDisplay];
        angle += .03;
    }
}

// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextClearRect(context, rect);
    CGContextBeginPath(context);
    CGContextSetFillColorWithColor(context, [UIColor whiteColor].CGColor);
    CGContextMoveToPoint(context, rect.size.width/2,rect.size.height/2);
    CGContextAddArc(context, rect.size.width/2,rect.size.height/2, rect.size.width/2, DEG2RAD(0), DEG2RAD(360*angle), 0);
    CGContextClosePath(context);
    CGContextFillPath(context);
}


@end