I've got a design a few days ago where the paddings are defined in percentages in regard to the screen width and height. It could be done with auto-layout, but I am not sure that this is a best practice. Before that I always used paddings like 16px from the left 16px from the right.
I don't know how apple do it, e.g. Does the padding of elements look the same on iPhone4 and iPhone6p in portrait? What is the best practice in native apps?
For example: the padding of the first element in a cell of tableview, it could be 12px or 5%.
It makes sense using percentages, but I couldn't find a reference which says that it should be done in that way or the other way.
So which one is the standard should I use pixel/point based padding for texts and buttons or ratio based?
Image, icon sizes are an exception of course.
Every size in the apple design guidelines and other guidelines are defined in points/pixels.
I hope my question isn't that broad, It could be answered with specific advantages and disadvantages or an article about the topic.