Pinch-to-zoom UILabel

Question

I'm handling a pinch gesture, and I am scaling a UILabel like this:

CGFloat factor = sender.scale;
view.transform = CGAffineTransformScale(view.transform, factor, factor);

The problem is when I zoom-in (make the label larger) it wont redraw itself, i.e. it becomes blurry. How do I make it sharp again?

Answer 1

The reason this happens is that transforms are applied to the rendered bitmap of the view's layer.

If you want to have the label's contents scaled adjust the contentsScale, too:

CGFloat scaleFactor = ...

view.layer.contentsScale = [UIScreen mainScreen].scale + scaleFactor;
view.transform           = CGAffineTransformMakeScale( scaleFactor, scaleFactor );