Everything in SwiftUI is a View. Event text.
To views we can add modifiers.
Modifiers are cool because they can be added to any view. Gone are the days when every control needed to have its own property (i.e. alpha).
Now you can add any modifier to any View and get the change you want. To see a list of which modifieres you can add use that search bar down in the bottom right.
Views are really lego combiners. They can combine subviews and return them as one combined big view. For example look at ZStack.
ZStack takes content in the form of a function. The function here is of type () -> _ meaning it takes no input but it does return something. It returns a bag of lego.
This bag of lego must be a View and it must support the @ViewBuilder attributes which means it will treat whatever it is passed as a list of views.
Never is an enum that represents something bad has happened. or should Never happen.
Because Swift knows you are going to want to make these bags of lego a lot it makes it really easy by enhancing the concept of a function to represent a bag of lego.
This function that you pass to a lego combiner view, is known as a ViewBuilder.
This ViewBuilder is a custom parameter that constructs a list of views from closures. It essentially list you list other views inside and then bags them together.
But what's cool about building this list of views in a closure is we can use if/then statements and even vars to dynamically build our views based the state of what is going on inside.
So ZStack stacks these views ontop of eachother out towards the user. Good for a stack of cards. And every View in SwiftUI is just some View. We always let the compiler figure out what's inside.
So this is basically the beginning of our card.
There are two types of modifiers:
- ones that affect the view
- ones that the affect the contained views
For example, when we add padding to a ZStack that affects the ZStack view.
ZStack is just a view. It can be padded list anything else.
But watch what happens when we put foreground on the ZStack. It affects everything inside.
But we can still override locally.
Swift can figure out what is going on. So we can clean things up a bit. We don't need to pass in content as an argument. It is a trailing function, so we can just inline it like this:
