Debug mode to draw guide lines on a font label

[graiz]

Example:

The text would perhaps be drawn on tap or selection.

[ZevEisenberg]

Nice graphic 😜

I like this idea. It could be on a subclass of UILabel, or perhaps a category with runtime magic (swizzling -drawTextInRect:). If a subclass, we could also add an IBDesignable to draw these lines in IB. unfortunately, you still can't align things by x-height or cap height directly in IB, so I don't know how useful that would be, but it would at least be a useful visualization tool.

Also: this should work on multi-line labels.