Display barcode scanning rectangle area in overlay with RedLaser SDK

gistfile1.m

- (void)viewDidLoad
{
    [super viewDidLoad];
    
    // Create rectangle layer and add it to view
    rectLayer = [CAShapeLayer layer];
    rectLayer.fillColor = [[UIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:0.2] CGColor];
    rectLayer.strokeColor = [[UIColor whiteColor] CGColor];
    rectLayer.lineWidth = 3;
    [self.view.layer addSublayer:rectLayer];
}

- (void) viewWillAppear:(BOOL)animated
{
    // Draw and display rectangle
    CGMutablePathRef path = CGPathCreateMutable();
    CGRect activeRegionRect = CGRectMake(0, 100, 320, 250);
    CGPathAddRect(path, NULL, activeRegionRect);
    [rectLayer setPath: path];
    CGPathRelease(path);
}