To measure views, SwiftUI provides GeometryReader. It’s quite a bit of hassle, but, one of the nice things about SwiftUI’s design is that you can isolate most of it in resuable pieces. Finally, that superview needs to use that info to re-do the layout.Next, we need to have these values “bubble up” to a superview somewhere that’s going to handle the layout.First, we need to get the sizes of the items we want to line up.I don’t know if this is the “right” way or an “intended” solution by Apple, and I hope we’ll eventually see a system more like matchedGeometryEffect but bidirectional, but in the meantime, here we go. So far, I’ve only found one way around this. And matchedGeometryEffect caught my attention as I was skimming the API change lists, but it’s still one-way, and looks like it’s intended mainly for transitions between layouts. I really hoped Apple would have a solution in iOS 14, and a couple of new additions seemed promising: the new LazyHGrid and LazyVGrid seemed like they could help, but so far (they’re still in beta) they don’t seem to solve these problems (if you could specify column/row sizes as percentages/ratios, that might help). But if you want them side-by-side instead? Now you’re in for a world of pain.Īnd a common layout, where you have two controls, each with a label, and you want them arranged in a neat 2x2 grid of label-view, label-view, is likewise quite difficult, because if you make a VStack of HStacks, or vice-versa, you can line up one of the axes, but not the other. If you want to make two buttons, and have them be the same width, and arranged one below the other, that’s easy: make a VStack and have them fill the available width.

As a result, you don’t want to hard-code a specific size. These are useful where you want some controls to be the same width, height, or both, but you don’t know in advance what that size will be - typically because it’s based on the size of a text label, and you want to support accessibility and localisation, which means different size fonts and different length labels.

This makes many common tasks fairly straightforward, but it lacks some of the features of Auto Layout - most notably, equal-size constraints. Superviews tell subviews how much space they have available, not the other way around. Over time the bugs will get fixed, and the missing features filled in.īut the layout engine has a significant limitation: unlike Auto Layout, it’s strictly one-way. There are bugs, and there are missing features - but mostly, the design is pretty solid. SwiftUI is quite a new technology, and it still has some rough edges.

Swiftui vstack size