Custom Back Button

backButton.m

- (UIView *)backButton
{
    // Button
    UIButton *backButton = [UIButton buttonWithType:UIButtonTypeCustom];
    backButton.frame = CGRectMake(0.0, 0.0, 50.0, 50.0);
    [backButton addTarget:self.navigationController action:@selector(popViewControllerAnimated:) forControlEvents:UIControlEventTouchUpInside];
    
    // Custom back arrow
    UIBezierPath *backArrowPath = [UIBezierPath bezierPath];
    [backArrowPath moveToPoint: CGPointMake(15, 25)];
    [backArrowPath addLineToPoint: CGPointMake(20, 31)];
    [backArrowPath addLineToPoint: CGPointMake(15, 35)];
    [backArrowPath addLineToPoint: CGPointMake(5, 25)];
    [backArrowPath addLineToPoint: CGPointMake(15, 15)];
    [backArrowPath addLineToPoint: CGPointMake(20, 20)];
    [backArrowPath addLineToPoint: CGPointMake(15, 25)];
    [backArrowPath closePath];
    
    CAShapeLayer *backArrowShapeLayer = [CAShapeLayer layer];
    backArrowShapeLayer.path = [backArrowPath CGPath];
    backArrowShapeLayer.strokeColor = [[UIColor grayColor] CGColor];
    backArrowShapeLayer.lineWidth = 1.0;
    backArrowShapeLayer.fillColor = nil;
    
    [backButton.layer addSublayer:backArrowShapeLayer];

    // TODO: Subclass button to set highlight state
    // http://robots.thoughtbot.com/post/33427366406/designing-for-ios-taming-uibutton
    
    return backButton;
}