How do I draw text into a containing view in UIView?

Question

In UIView, I want to draw text into its containing view using drawInRect:withFont:lineBreakMode call but that operates on the current context only. Is it possible to draw that text into a subview from current view? The subview is a generic UIView instance and I don't really want to create a new UIView-derived class just for this purpose if I can avoid it.

Answer 1

No, you can't do what you describe. Subclassing UIView is exactly the method you're supposed to use for this— there's nothing wrong with creating a UIView subclass which only has a simple -drawRect: method.

Answer 2

No, if you're going to do something with a context, you have to be in that view's -drawRect:. You can always make your subview a UIView subclass that overrides -drawRect: to display the text you want... but at that point, you're kind of reinventing UILabel.

Answer 3

One option would be to add a CALayer to the view's layer instead of adding a UIView to the view. The CALayer has a delegate property which you can assign any object to. The CALayer calls:

- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx

on the delegate, which you can take to do something like:

- (void)drawLayer:(CALayer *)layer inContext:(CGContextRef)ctx {
    if (layer == myLayer) {
        UIGraphicsPushContext(ctx);
        [string drawInRect:rect withFont:font lineBreakMode:mode];
        UIGraphicsPopContext();
    }
}