7. The data transfer to the sub-View
LandmarkDetail Now still use hard-coded data to display landmarks. Like LandmarkRow the same LandmarkDetail type, and other combinations of view it requires a landmark property as their data sources.
At the beginning of the sub-contents view, we will CircleImage , MapView and LandmarkDetail the display to the incoming data from the hard-coded. SwiftUI official tutorial
In 7.1 CircleImage.swif , add storage attributes image . SwiftUI Tutorial
This is done using SwiftUI a common mode of building view. Our custom view often is a particular view of some of the packaging and packaging modifiers .
CircleImage.swift
import SwiftUI
struct CircleImage: View {
var image: Image
var body: some View {
image
.clipShape(Circle())
.overlay(Circle().stroke(Color.white, lineWidth: 4))
.shadow(radius: 10)
}
}
struct CircleImage_Preview: PreviewProvider {
static var previews: some View {
CircleImage()
}
}
7.2 update preview provider , pass a Turtle Rock picture.
CircleImage.swift
import SwiftUI
struct CircleImage: View {
var image: Image
var body: some View {
image
.clipShape(Circle())
.overlay(Circle().stroke(Color.white, lineWidth: 4))
.shadow(radius: 10)
}
}
struct CircleImage_Preview: PreviewProvider {
static var previews: some View {
CircleImage(image: Image("turtlerock"))
}
}
7.3 MapView.swift in to MapView add an coordinate attribute, then the use of hard-coded into latitude and longitude of this property. SwiftUI Tutorial
MapView.swift
import SwiftUI
import MapKit
struct MapView: UIViewRepresentable {
var coordinate: CLLocationCoordinate2D
func makeUIView(context: Context) -> MKMapView {
MKMapView(frame: .zero)
}
func updateUIView(_ view: MKMapView, context: Context) {
let span = MKCoordinateSpan(latitudeDelta: 0.02, longitudeDelta: 0.02)
let region = MKCoordinateRegion(center: coordinate, span: span)
view.setRegion(region, animated: true)
}
}
struct MapView_Preview: PreviewProvider {
static var previews: some View {
MapView()
}
}
7.4 update preview provider , a first pass landmark coordinate data array.
MapView.swift
import SwiftUI
import MapKit
struct MapView: UIViewRepresentable {
var coordinate: CLLocationCoordinate2D
func makeUIView(context: Context) -> MKMapView {
MKMapView(frame: .zero)
}
func updateUIView(_ view: MKMapView, context: Context) {
let span = MKCoordinateSpan(latitudeDelta: 0.02, longitudeDelta: 0.02)
let region = MKCoordinateRegion(center: coordinate, span: span)
view.setRegion(region, animated: true)
}
}
struct MapView_Preview: PreviewProvider {
static var previews: some View {
MapView(coordinate: landmarkData[0].locationCoordinate)
}
}
7.5 In the LandmarkDetail.swift middle, SwiftUI tutorial to LandmarkDetail add the type landmark attribute.
LandmarkDetail.swift
import SwiftUI
struct LandmarkDetail: View {
var landmark: Landmark
var body: some View {
VStack {
MapView()
.frame(height: 300)
CircleImage()
.offset(y: -130)
.padding(.bottom, -130)
VStack(alignment: .leading) {
Text("Turtle Rock")
.font(.title)
HStack(alignment: .top) {
Text("Joshua Tree National Park")
.font(.subheadline)
Spacer()
Text("California")
.font(.subheadline)
}
}
.padding()
Spacer()
}
}
}
struct LandmarkDetail_Preview: PreviewProvider {
static var previews: some View {
LandmarkDetail()
}
}
7.6 update preview provider , using landmarkData the first landmark.
LandmarkDetail.swift
import SwiftUI
struct LandmarkDetail: View {
var landmark: Landmark
var body: some View {
VStack {
MapView()
.frame(height: 300)
CircleImage()
.offset(y: -130)
.padding(.bottom, -130)
VStack(alignment: .leading) {
Text("Turtle Rock")
.font(.title)
HStack(alignment: .top) {
Text("Joshua Tree National Park")
.font(.subheadline)
Spacer()
Text("California")
.font(.subheadline)
}
}
.padding()
Spacer()
}
}
}
struct LandmarkDetail_Preview: PreviewProvider {
static var previews: some View {
LandmarkDetail(landmark: landmarkData[0])
}
}
7.7 will be required to pass data to our custom type.
LandmarkDetail.swift
import SwiftUI
struct LandmarkDetail: View {
var landmark: Landmark
var body: some View {
VStack {
MapView(coordinate: landmark.locationCoordinate)
.frame(height: 300)
CircleImage(image: landmark.image(forSize: 250))
.offset(y: -130)
.padding(.bottom, -130)
VStack(alignment: .leading) {
Text(landmark.name)
.font(.title)
HStack(alignment: .top) {
Text(landmark.park)
.font(.subheadline)
Spacer()
Text(landmark.state)
.font(.subheadline)
}
}
.padding()
Spacer()
}
}
}
struct LandmarkDetail_Preview: PreviewProvider {
static var previews: some View {
LandmarkDetail(landmark: landmarkData[0])
}
}
7.8 Finally, call the navigationBarTitle(_:displayMode:) method to add a navigation bar to display the title when the details view.
LandmarkDetail.swift
import SwiftUI
struct LandmarkDetail: View {
var landmark: Landmark
var body: some View {
VStack {
MapView(coordinate: landmark.locationCoordinate)
.frame(height: 300)
CircleImage(image: landmark.image(forSize: 250))
.offset(y: -130)
.padding(.bottom, -130)
VStack(alignment: .leading) {
Text(landmark.name)
.font(.title)
HStack(alignment: .top) {
Text(landmark.park)
.font(.subheadline)
Spacer()
Text(landmark.state)
.font(.subheadline)
}
}
.padding()
Spacer()
}
.navigationBarTitle(Text(landmark.name), displayMode: .inline)
}
}
struct LandmarkDetail_Preview: PreviewProvider {
static var previews: some View {
LandmarkDetail(landmark: landmarkData[0])
}
}
7.9 SceneDelegate.swift in the app's rootView changed LandmarkList .
When we do not use the preview but run independently app in the simulator, app will be SceneDelegate defined in the rootViewdisplay begins.
SceneDelegate.swift
import UIKit
import SwiftUI
class SceneDelegate: UIResponder, UIWindowSceneDelegate {
var window: UIWindow?
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {
// Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
// If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
// This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
// Use a UIHostingController as window root view controller
let window = UIWindow(frame: UIScreen.main.bounds)
window.rootViewController = UIHostingController(rootView: LandmarkList())
self.window = window
window.makeKeyAndVisible()
}
// ...
}
7.10 LandmarkList.swift , the target to LandmarkDetail pass the current landmark.
LandmarkList.swift
import SwiftUI
struct LandmarkList: View {
var body: some View {
NavigationView {
List(landmarkData) { landmark in
NavigationButton(destination: LandmarkDetail(landmark: landmark)) {
LandmarkRow(landmark: landmark)
}
}
.navigationBarTitle(Text("Landmarks"))
}
}
}
struct LandmarkList_Previews: PreviewProvider {
static var previews: some View {
LandmarkList()
}
}
7.11 to switch to real-time preview, you can see the view from the list to navigate to the correct landmark for more information.
