When scrolling is enabled on a UITextView, it has no intrinsic content size and so, in the absence of height constraints, it will collapse to zero height. When scrolling is disabled, it does have an intrinsic content size--but this size doesn't depend on the width and so isn't generally useful for width-constrained text.
In some cases, it is preferable to allow the UITextView to expand to its natural height, subject to a maximum height limit, with scrolling enabled only when the text's size requires it.
This implementation of SelfSizingTextView computes an intrinsic content size based on its width, whether or not scrolling is enabled. If you install a vertical constraint that caps its height and set isScrollingEnabled to true, it will take as much space as it needs, subject to the height constraint, allowing scrolling only if the text needs more room.
Includes a simple demo app showing the behavior with short and long text, and with and without scrolling and/or constraints.
