How to make SwiftUI View expand available space? - ios

Question

I am trying to make a SwiftUI View expand its available space. I have a MapView which uses the MapKit to display a map on the screen. I would like this map to expand the available space in the VStack. You can see it is above a view colored red, and below a search bar. If i make the red colored view have a height of 100, then the MapView shrinks down. If I do not set the height on the red colored view, then the MapView is bigger however the red view does not look as I want.
I want the red view to have a height of 100, and the MapView to fill all available height underneath the search bar, and above the red view.
ContentView:
struct ContentView: View {
#ObservedObject
var viewModel: HomeViewModel
var body: some View {
NavigationView {
ZStack {
ColorTheme.brandBlue.value.edgesIgnoringSafeArea(.all)
VStack {
CardView {
EditText(hint: "Search", text: self.$viewModel.searchText, textContentType: UITextContentType.organizationName)
}
MapView(annotations: self.$viewModel.restaurantAnnotations)
.cornerRadius(8)
CardView(height: 100) {
HStack {
Color.red
}
}
}
}
.navigationBarTitle("", displayMode: .inline)
.navigationBarHidden(true)
.navigationBarBackButtonHidden(true)
}
}
}
CardView
struct CardView<Content>: View where Content : View {
var height: CGFloat = .infinity
var content: () -> Content
var body: some View {
content()
.padding(EdgeInsets.init(top: 0, leading: 8, bottom: 8, trailing: 8))
.background(Color.white.cornerRadius(8))
.shadow(radius: 2, x: 0, y: 1)
.frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: height)
}
}
EditText
struct EditText: View {
var hint: String
#Binding
var text: String
var label: String = ""
var textContentType: UITextContentType? = .none
var keyboardType: UIKeyboardType = .default
var textSize: CGFloat = 16
var body: some View {
return VStack(alignment: .leading) {
Text(label).font(.system(size: 12)).bold()
.foregroundColor(ColorTheme.text.value)
HStack {
TextField(hint, text: $text)
.lineLimit(1)
.font(.system(size: textSize))
.textContentType(textContentType)
.keyboardType(keyboardType)
.foregroundColor(ColorTheme.text.value)
}
Divider().background(ColorTheme.brandBlue.value)
}
}
}
MapView
struct MapView: UIViewRepresentable {
#Binding
var annotations: [MKAnnotation]
func makeUIView(context: Context) -> MKMapView {
let mapView = MKMapView()
mapView.delegate = context.coordinator
return mapView
}
func updateUIView(_ view: MKMapView, context: Context) {
view.delegate = context.coordinator
view.addAnnotations(annotations)
if annotations.count == 1 {
let coords = annotations.first!.coordinate
let region = MKCoordinateRegion(center: coords, span: MKCoordinateSpan(latitudeDelta: 0.1, longitudeDelta: 0.1))
view.setRegion(region, animated: true)
}
}
func makeCoordinator() -> MapViewCoordinator {
MapViewCoordinator(self)
}
}
MapViewCoordinator
class MapViewCoordinator: NSObject, MKMapViewDelegate {
var mapViewController: MapView
init(_ control: MapView) {
self.mapViewController = control
}
func mapView(_ mapView: MKMapView, viewFor annotation: MKAnnotation) -> MKAnnotationView?{
//Custom View for Annotation
let identifier = "Placemark"
if let annotationView = mapView.dequeueReusableAnnotationView(withIdentifier: identifier) {
annotationView.annotation = annotation
return annotationView
} else {
let annotationView = MKPinAnnotationView(annotation: annotation, reuseIdentifier: identifier)
annotationView.isEnabled = true
annotationView.canShowCallout = true
let button = UIButton(type: .infoDark)
annotationView.rightCalloutAccessoryView = button
return annotationView
}
return nil
}
}
As you can see the MapView does not fill the available space
Now all the available space is filled but the red view height is not 100

Answer 1

Here is a solution (tested with Xcode 11.4):
struct CardView<Content>: View where Content : View {
var height: CGFloat? = nil // << here !!
Note: defined height, even with .infinity, made your upper card equivalent by requesting height to map view, so they divided free space; when height is not specified, the component tights to content