DAVElopment - Dave's Blog on Coding and Software Development

You have an image containing text. As such, there’s lots of sharp edges. You want to put this image into a scroll view and allow the user to zoom in with a pinch gesture. This is very easy to implement in iOS. Technically, you don’t even need to write code. This can all be done in Interface Builder. However, the further the image is zoomed the blurrier it looks. Solution 1 Start with a fully zoomed of the image and scale it down when initially adding it to the scroll view. After all, it’s much easier to scale an image down and keep it looking good than it is to scale it up. So during the whole zoom operation the image being displayed is a scaled down version of the original. This would work great except that iOS doesn’t apply the right interpolation when scaling the original large down to fit into the initial smaller frame. You would think self.imageView.layer.minificationFilter = kCAFilterTrilinear; would do the trick but it doesn’t. I could be doi...

View transformations are something you might wanna need to learn more about. While rethinking the iPad interface for his UTC Chart app, it occurred to mluton to use vertical labels. After a bit of research this is what he came up with. - (void)viewDidLoad { [super viewDidLoad]; NSString *string = @"Lorem Ipsum"; UIFont *font = [UIFont preferredFontForTextStyle:UIFontTextStyleHeadline]; UILabel *label = [[UILabel alloc] init]; label.font = font; label.text = string; CGSize size = [string sizeWithAttributes:@{NSFontAttributeName:font}]; label.frame = CGRectMake(40, 40, size.width, size.height); [label.layer setAnchorPoint:CGPointMake(0.0, 0.0)]; label.transform = CGAffineTransformMakeRotation((M_PI) / 2); [self.view addSubview:label]; } The frame and setAnchorPoint values can be modified to achieve desired positioning. He chose to bypass any potential autolayout/transform conflicts by creating the label progr...