Named coordinate spaces, however, let a view name its own coordinate space which can later be references by other views. The frame function let us obtain a rect of the suggested area, using different coordinate spaces. The safeAreaInsets are also exposed through the GeometryProxy. But remember, that is up to us, the children. As seen in the example, size is a property that contains the size suggested by the parent. Now that we have GeometryReader, it is very simple: Almost everything is a view with SwiftUI! As you will see in the example below, GeometryReader lets YOU define its contents, but unlike other views, you also have access to some useful information you can seize to do your thing in the process.Ĭonsider the exercise we mentioned before: Make a view that draws a rectangle with half the size of the parent’s suggestion and positions it 5 points to the right side of the suggested area. Let’s begin by actually looking to the documentation Apple provides about GeometryReader:Ī container view that defines its content as a function of its own size and coordinate space.Ĭomparing to other entries that only say “No overview available”, we can consider ourselves lucky!īut what does this mean anyway? Well basically, GeometryReader is yet another view! Surprised? I guess you’re not by now.
Here is where GeometryReader comes to the rescue. So how do we go off script here? It turns out, is not that complicated. If the child view is not happy with what its was offered, then he can just ignore it.įor example, if you want your custom view to draw a rectangle with half the size of the one suggested by your parent, and if you want to positioned it 5 points to the right edge of the suggested location, then so be it. However, as explained on session 237, parents suggest a size and position, but it is up to the child view to decide where and how to draw itself. If you would like to learn more about how parents determine size and position for their children, I strongly suggest you watch the 2019 WWDC session 237 ( Building Custom Views with SwiftUI). In this case, the containing VStack is such parent.
Let SwiftUI figure out where and how big the parent wants it.
As you can see, the view MyRectangle() does not worry about size.
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