Overlay a color over SwiftUI view? - swift

For my SwiftUI notes app, I would like to overlay a color over the entire view, but I've only been able to cover half off the screen with the color. Other attempts at setting the color and an overlay has only resulted in errors so far. Is there a solution to this? Or should go about this another way? Image has been provided as well. 1
import SwiftUI
let dateFormatter2 = DateFormatter()
struct NoteItem2: Codable, Hashable, Identifiable {
let id: Int
let text: String
var date = Date()
var dateText: String {
dateFormatter.dateFormat = "h:mm a"
return dateFormatter.string(from: date)
}
}
struct green_screen : View {
#State var items: [NoteItem] = {
guard let data = UserDefaults.standard.data(forKey: "notes") else { return [] }
if let json = try? JSONDecoder().decode([NoteItem].self, from: data) {
return json
}
return []
}()
#State var taskText: String = ""
#State var showAlert = false
#State var itemToDelete: NoteItem?
var alert: Alert {
Alert(title: Text("Hey!"),
message: Text("Are you sure you want to delete this item?"),
primaryButton: .destructive(Text("Delete"), action: deleteNote),
secondaryButton: .cancel())
}
var inputView: some View {
Color.green
.overlay(
HStack {
TextField("Write a note for yourself...", text: $taskText)
.padding(EdgeInsets(top: 0, leading: 16, bottom: 0, trailing: 16))
.clipped()
Button(action: didTapAddTask, label: { Text("Add") }).padding(8)
})
.edgesIgnoringSafeArea(.all)
}
var body: some View {
VStack {
inputView
Divider()
List(items) { item in
VStack(alignment: .leading) {
Text(item.dateText).font(.headline)
Text(item.text).lineLimit(nil).multilineTextAlignment(.leading)
}
.onLongPressGesture {
self.itemToDelete = item
self.showAlert = true
}
}
.alert(isPresented: $showAlert, content: {
alert
})
}
}
func didTapAddTask() {
let id = items.reduce(0) { max($0, $1.id) } + 1
items.insert(NoteItem(id: id, text: taskText), at: 0)
taskText = ""
save()
}
func deleteNote() {
guard let itemToDelete = itemToDelete else { return }
items = items.filter { $0 != itemToDelete }
save()
}
func save() {
guard let data = try? JSONEncoder().encode(items) else { return }
UserDefaults.standard.set(data, forKey: "notes")
}
}
struct green_screen_Previews: PreviewProvider {
static var previews: some View {
green_screen()
}
}

First you have to add green color to entire view instead of the inputView.
var inputView: some View {
GeometryReader{ geo in
HStack {
TextField("Write a note for yourself...", text: $taskText)
.padding(EdgeInsets(top: 0, leading: 16, bottom: 0, trailing: 16))
.clipped()
Button(action: didTapAddTask, label: { Text("Add") }).padding(8)
}
.frame( height: geo.size.height/2)
}
}
and main view
VStack {
inputView
Divider()
List(items) { item in
VStack(alignment: .leading) {
Text(item.dateText).font(.headline)
Text(item.text).lineLimit(nil).multilineTextAlignment(.leading)
}
.onLongPressGesture {
self.itemToDelete = item
self.showAlert = true
}
}
.listRowBackground(Color.green)
.alert(isPresented: $showAlert, content: {
alert
})
}
.background(Color.green) // <-- here
.ignoresSafeArea() // <-- here
after this modification also you cannot see the color overlay on entire screen because of SwiftUI list block the view color from it's default background color.so you need to change it clear color,
init() {
UITableView.appearance().separatorStyle = .none
UITableViewCell.appearance().backgroundColor = .clear
UITableView.appearance().backgroundColor = .clear
}

Related

Dynamic list from TextField's data SwiftUI

I just started to learn Swift programing language and have a question.
I'm trying to create a simple one-page application where you can add movies to a favorite list. Movies must have 2 properties: title (string, mandatory) and year (integer, mandatory). But I have a problem, I don't know how to put it in one row.
And also, how to ignore duplicate movies?
import SwiftUI
struct Movie: Identifiable {
let id = UUID()
var title: String
}
class Model: ObservableObject {
#Published var movies: [Movie] = []
}
struct DynamicList: View {
#StateObject var model = Model()
#State var text = ""
#State var year = ""
var body: some View {
VStack {
Section() {
TextField("Title", text: $text)
.padding()
.border(.gray)
TextField("Year", text: $year)
.padding()
.border(.gray)
.keyboardType(.numberPad)
Button(action: {
self.addToList()
}, label: {
Text("Add")
.frame(width: 80, height: 40, alignment: .center)
.background(Color.blue)
.cornerRadius(8)
.foregroundColor(.white)
})
.padding()
}
List {
ForEach(model.movies) { movie in
MovieRow(title: movie.title)
}
}
}
.padding()
}
func addToList() {
guard !text.trimmingCharacters(in: .whitespaces).isEmpty else {
return
}
guard !year.trimmingCharacters(in: .whitespaces).isEmpty else {
return
}
let newMovie = Movie(title: text)
model.movies.append(newMovie)
text = ""
let newYear = Movie(title: year)
model.movies.append(newYear)
year = ""
}
}
struct MovieRow: View {
let title: String
var body: some View {
Label (
title: { Text(title)},
icon: { Image(systemName: "film") }
)
}
}
struct DynamicList_Previews: PreviewProvider {
static var previews: some View {
DynamicList()
}
}
Here is the solution. It will show the data in one row and also how to ignore duplicate movies to show into the list. Check the below code:
import SwiftUI
struct Movie: Identifiable {
var id = UUID()
let title: String
let year: String
}
class MoviesViewModel: ObservableObject {
#Published var movies: [Movie] = []
}
struct ContentView: View {
#State var boolValue = false
#StateObject var viewModel = MoviesViewModel()
#State var text = ""
#State var year = ""
var body: some View {
VStack {
Section() {
TextField("Title", text: $text)
.padding()
.border(.gray)
TextField("Year", text: $year)
.padding()
.border(.gray)
.keyboardType(.numberPad)
Button(action: {
self.addToList()
}, label: {
Text("Add")
.frame(width: 80, height: 40, alignment: .center)
.background(Color.blue)
.cornerRadius(8)
.foregroundColor(.white)
})
.padding()
}
// Show the data in list form
List {
ForEach(viewModel.movies) { movie in
MovieRow(title: movie.title, year: movie.year)
}
}
}
.padding()
}
func addToList() {
guard !text.trimmingCharacters(in: .whitespaces).isEmpty else {
return
}
guard !year.trimmingCharacters(in: .whitespaces).isEmpty else {
return
}
// Condition to check whether the data is already exit or not
boolValue = false
let newMovie = Movie(title: text, year: year)
for movie in viewModel.movies{
if ((movie.title.contains(text)) && (movie.year.contains(year))){
boolValue = true
}
}
// check if boolValue is false so the data will store into the array.
if boolValue == false{
viewModel.movies.append(newMovie)
text = ""
year = ""
}
}
}
struct MovieRow: View {
let title: String
let year: String
var body: some View {
// Show the data insert into the textfield
HStack{
Label (
title: { Text(title)},
icon: { Image(systemName: "film") }
)
Spacer()
Label (
title: { Text(year)},
icon: { Image(systemName: "calendar") }
)
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
Maybe someone will need a similar solution, here is my result:
import SwiftUI
struct Movie: Identifiable {
let id = UUID()
var title: String
var year: String
}
class Model: ObservableObject {
#Published var movies: [Movie] = []
}
struct DynamicList: View {
#StateObject var model = Model()
#State var text = ""
#State var year = ""
var body: some View {
VStack {
Section() {
TextField("Title", text: $text)
.padding()
.border(.gray)
TextField("Year", text: $year)
.padding()
.border(.gray)
.keyboardType(.numberPad)
Button(action: {
self.addToList()
}, label: {
Text("Add")
.frame(width: 80, height: 40, alignment: .center)
.background(Color.blue)
.cornerRadius(8)
.foregroundColor(.white)
})
.padding()
}
List {
ForEach(model.movies) { movie in
MovieRow(title: movie.title, year: movie.year)
}
}
}
.padding()
}
func addToList() {
guard !text.trimmingCharacters(in: .whitespaces).isEmpty else {
return
}
guard !year.trimmingCharacters(in: .whitespaces).isEmpty else {
return
}
let newMovie = Movie(title: text, year: year)
model.movies.append(newMovie)
text = ""
year = ""
}
}
struct MovieRow: View {
let title: String
let year: String
var body: some View {
Label (
title: { Text(title + " " + year)},
icon: { Image(systemName: "film") }
)
}
}
struct DynamicList_Previews: PreviewProvider {
static var previews: some View {
DynamicList()
}
}

How do I update the data in the tabview after the one-to-many coredata has been modified?

Purpose
I want to update the data in the tabview automatically when I return to the RootView after I rename the tag name in the tagManagemenView.
Current Status
When I do delete operation in the TagManagementView, the RootView is able to update automatically.
However, If the Tag name is modified, the RootView display will not be updated, but clicking into the ItemDetailsView is able to display the latest modified name. Only the display of the RootView is not updated.
Background and code
Item and Tag are created using coredata and have a one-to-many relationship, where one Item corresponds to multiple Tags
// RootView
struct RootView: View {
#State private var selection = 0
var body: some View {
NavigationView {
TabView(selection: $selection) {
ItemListView()
.tabItem {
Label ("Items",systemImage: "shippingbox")
}
.tag(0)
Settings()
.tabItem{
Label("Settings", systemImage: "gearshape")
}
.tag(1)
}
.navigationTitle(selection == 0 ? "Items" : "Settings")
}
.navigationViewStyle(.stack)
}
}
// ItemListView
struct ItemListView: View {
#FetchRequest var items: FetchedResults<Item>
#State private var itemDetailViewIsShow: Bool = false
#State private var selectedItem: Item? = nil
init() {
var predicate = NSPredicate(format: "TRUEPREDICATE"))
_items = FetchRequest(fetchRequest: Item.fetchRequest(predicate))
}
var body: some View {
ForEach(items) { item in
Button(action: {
self.selectedItem = item
self.itemDetailViewIsShow = true
}, label: {
ItemCellView(item: item)
})
}
if selectedItem != nil {
NavigationLink (
destination: ItemDetailView(item: selectedItem!, detailViewIsShow: $itemDetailViewIsShow),
isActive: $itemDetailViewIsShow
) {
EmptyView()
}
.isDetailLink(false)
}
}
}
// TagManagementView
struct TagManagementView: View {
#Environment(\.managedObjectContext) var context
#FetchRequest(entity: Tag.entity(), sortDescriptors: []) var allTags: FetchedResults<Tag>
#State var isShowDeleteAlert = false
#State var showModel = false
#State var selected: Tag?
var body: some View {
ZStack {
List {
ForEach(allTags) { tag in
TagCellView(tag: tag)
.swipeActions(edge: .trailing, allowsFullSwipe: false) {
Button(role: .destructive, action: {
isShowDeleteAlert = true
selected = tag
}, label: {
Label("Delete", systemImage: "trash")
.foregroundColor(.white)
})
Button(action: {
showModel = true
selected = tag
}, label: {
Label("Edit", systemImage: "square.and.pencil")
.foregroundColor(.white)
})
}
}
.confirmationDialog("Delete confirm", isPresented: self.$isShowDeleteAlert, titleVisibility: .visible) {
Button("Delete", role: .destructive) {
if self.selected != nil {
self.selected!.delete(context: context)
}
}
Button(role: .cancel, action: {
isShowDeleteAlert = false
}, label: {
Text("Cancel")
.font(.system(size: 17, weight: .medium))
})
}
}
if self.showModel {
// background...
Color("mask").edgesIgnoringSafeArea(.all)
TagEditorModal(selected: self.$selected, isShowing: self.$showModel)
}
}
}
}
// TagEditorModal
struct TagEditorModal: View {
#Environment(\.managedObjectContext) var context
#State var tagName: String = ""
#Binding var isShowing: Bool
#Binding var selector: Tag?
init (selected: Binding<Tag?>, isShowing: Binding<Bool>) {
_isShowing = isShowing
_selector = selected
_tagName = .init(wrappedValue: selected.wrappedValue!.name)
}
var body: some View {
VStack{
TextField("Tag name", text: self.$tagName)
HStack {
Button(action: {
self.isShowing = false
}) {
Text("Cancel")
}
Button(action: {
self.selector!.update(name: self.tagName, context: context)
self.isShowing = false
}, label: {
Text("Submit")
})
}
}
}
}
// update tagName func
extension Tag {
func update(name: String, context: NSManagedObjectContext) {
self.name = name
self.updatedAt = Date()
self.objectWillChange.send()
try? context.save()
}
}
// ItemCellView
struct ItemCellView: View {
#Environment(\.managedObjectContext) var context
#ObservedObject var item: Item
var body: some View {
VStack {
Text(item.name)
TagListView(tags: .constant(item.tags))
}
}
}
// tagListView
struct TagListView: View {
#Binding var tags: [Tag]
#State private var totalHeight = CGFloat.zero
var body: some View {
VStack {
GeometryReader { geo in
VStack(alignment: .leading,spacing: 10) {
ForEach (getRows(screenWidth: geo.size.width), id: \.self) {rows in
HStack(spacing: 4) {
ForEach (rows) { tag in
Text(tag.name)
.font(.system(size: 10))
.fontWeight(.medium)
.lineLimit(1)
.cornerRadius(40)
}
}
}
}
.frame(width: geo.size.width, alignment: .leading)
.background(viewHeightReader($totalHeight))
}
}
.frame(height: totalHeight)
}
private func viewHeightReader(_ binding: Binding<CGFloat>) -> some View {
return GeometryReader { geo -> Color in
let rect = geo.frame(in: .local)
DispatchQueue.main.async {
binding.wrappedValue = rect.size.height
}
return .clear
}
}
func getRows(screenWidth: CGFloat) -> [[Tag]] {
var rows: [[Tag]] = []
var currentRow: [Tag] = []
var totalWidth: CGFloat = 0
self.tags.forEach{ tag in
totalWidth += (tag.size + 24)
if totalWidth > (screenWidth) {
totalWidth = (!currentRow.isEmpty || rows.isEmpty ? (tag.size + 24) : 0)
rows.append(currentRow)
currentRow.removeAll()
currentRow.append(tag)
} else {
currentRow.append(tag)
}
}
if !currentRow.isEmpty {
rows.append(currentRow)
currentRow.removeAll()
}
return rows
}
}
I added a TagCellView and then used an #ObservedObject for the tag
struct TagChipsView: View {
#ObservedObject var tag: Tag
let verticalPadding: CGFloat = 2.0
let horizontalPadding: CGFloat = 8.0
var body: some View {
Text(tag.name)
}
}

Why do I lose Data here?(SwiftUI)

I have two pages in my app TodayPage and CalendarList page.
I use EnvironmentObject wrapper to pass data between these two pages.
When TodayPage appears on onAppear modifier I call a function to generate days of calendar for me till now everything works fine when I add text to the list of TodayPage then go to the calendarList page and come back again to TodayPage all of the text that I addd to list are gone.I find out I can avoid lost of data by adding simple if to onAppear but I'm not sure this solution is right.
I have to upload lots of code ,Thanks for your help
( DataModel ) :
import SwiftUI
import Foundation
import Combine
struct Day : Identifiable {
var id = UUID()
var name : String
var date : String
var month : String
var List : [Text1?]
}
struct Text1 : Identifiable , Hashable{
var id = UUID()
var name: String
var color: Color
}
class AppState : ObservableObject {
#Published var dataLoaded = false
#Published var allDays : [Day] = [.init(name : "",date: "",month: "",List : [])]
func getDays(number: Int) -> [Day] {
let today = Date()
let formatter = DateFormatter()
return (0..<number).map { index -> Day in
let date = Calendar.current.date(byAdding: .day, value: index, to: today) ?? Date()
return Day(name: date.dayOfWeek(withFormatter: formatter) ?? "", date: "\(Calendar.current.component(.day, from: date))", month: date.nameOfMonth(withFormatter: formatter) ?? "", List: [])
}
}
}
extension Date {
func dayOfWeek(withFormatter dateFormatter: DateFormatter) -> String? {
dateFormatter.dateFormat = "EEEE"
return dateFormatter.string(from: self).capitalized
}
func nameOfMonth(withFormatter dateFormatter: DateFormatter) -> String? {
dateFormatter.dateFormat = "LLLL"
return dateFormatter.string(from: self).capitalized
}
}
class AddListViewViewModel : ObservableObject {
#Published var textItemsToAdd : [Text1] = [.init(name: "", color: .clear)] //start with one empty item
func saveToAppState(appState: AppState) {
appState.allDays[0].List.append(contentsOf: textItemsToAdd.filter {
!$0.name.isEmpty })
}
func bindingForId(id: UUID) -> Binding<String> {
.init { () -> String in
self.textItemsToAdd.first(where: { $0.id == id })?.name ?? ""
} set: { (newValue) in
self.textItemsToAdd = self.textItemsToAdd.map {
guard $0.id == id else {
return $0
}
return .init(id: id, name: newValue, color: .clear)
}
}
}
}
List view :
struct ListView: View {
#State private var showAddListView = false
#EnvironmentObject var appState : AppState
#Binding var dayList : [Text1?]
var title : String
var body: some View {
NavigationView {
VStack {
ZStack {
List(dayList, id : \.self){ text in
Text(text?.name ?? "")
}
if showAddListView {
AddListView(showAddListView: $showAddListView)
.offset(y:-100)
}
}
}
.navigationTitle(title)
.navigationBarItems(trailing:
Button(action: {showAddListView = true}) {
Image(systemName: "plus")
.font(.title2)
}
)
}
}
}
pop up menu View(for adding text into the list)
struct AddListView: View {
#Binding var showAddListView : Bool
#EnvironmentObject var appState : AppState
#StateObject private var viewModel = AddListViewViewModel()
var body: some View {
ZStack {
Title(addItem: { viewModel.textItemsToAdd.append(.init(name: "", color: .clear)) })
VStack {
ScrollView {
ForEach(viewModel.textItemsToAdd, id: \.id) { item in //note this is id: \.id and not \.self
PreAddTextField(textInTextField: viewModel.bindingForId(id: item.id))
}
}
}
.padding()
.offset(y: 40)
Buttons(showAddListView: $showAddListView, save: {
viewModel.saveToAppState(appState: appState)
})
}
.frame(width: 300, height: 200)
.background(Color.white)
.shadow(color: Color.black.opacity(0.3), radius: 10, x: 0, y: 10)
}
}
struct PreAddTextField: View {
#Binding var textInTextField : String
var body: some View {
VStack {
TextField("Enter text", text: $textInTextField)
}
}
}
struct Buttons: View {
#Binding var showAddListView : Bool
var save : () -> Void
var body: some View {
VStack {
HStack(spacing:100) {
Button(action: {
showAddListView = false}) {
Text("Cancel")
}
Button(action: {
showAddListView = false
save()
}) {
Text("Add")
}
}
}
.offset(y: 70)
}
}
struct Title: View {
var addItem : () -> Void
var body: some View {
VStack {
HStack {
Text("Add Text to list")
.font(.title2)
Spacer()
Button(action: {
addItem()
}) {
Image(systemName: "plus")
.font(.title2)
}
}
.padding()
Spacer()
}
}
}
TodayPage View :
struct TodayPage: View {
#EnvironmentObject var appState : AppState
var body: some View {
ListView(dayList: $appState.allDays[0].List, title: "Today")
.onAppear {
// To avoid data lost , we can use simple if below but I'm not sure it's a right solution
// if appState.dataLoaded == false {
appState.allDays = appState.getDays(number: 365)
// appState.dataLoaded = true
// }
}
}
}
CalendarListPage :
struct CalendarList: View {
#EnvironmentObject var appState : AppState
var body: some View {
NavigationView {
List {
ForEach(appState.allDays.indices, id:\.self) { index in
NavigationLink(destination: ListView(appState: _appState, dayList: $appState.allDays[index].List, title: appState.allDays[index].name).navigationBarTitleDisplayMode(.inline) ) {
HStack(alignment: .top) {
RoundedRectangle(cornerRadius: 23)
.frame(width: 74, height: 74)
.foregroundColor(Color.blue)
.overlay(
VStack {
Text(appState.allDays[index].date)
.font(.system(size: 35, weight: .regular))
.foregroundColor(.white)
Text(appState.allDays[index].month)
.foregroundColor(.white)
}
)
.padding(.trailing ,4)
VStack(alignment: .leading, spacing: 5) {
Text(appState.allDays[index].name)
.font(.system(size: 20, weight: .semibold))
}
}
.padding(.vertical ,6)
}
}
}
.navigationTitle("Calendar")
}.onAppear {
}
.navigationViewStyle(StackNavigationViewStyle())
}
}
and finally TabBar :
struct TabBar: View {
var body: some View {
let appState = AppState()
TabView {
TodayPage().tabItem {
Image(systemName: "info.circle")
Text("Today")
}
CalendarList().tabItem {
Image(systemName: "square.fill.text.grid.1x2")
Text("Calendar")
}
}
.environmentObject(appState)
}
}
Right now, because your let appState is inside the body of TabBar, it gets recreated every time TabBar is rendered. Instead, store it as a #StateObject (or #ObservedObject if you are pre iOS 14):
struct TabBar: View {
#StateObject var appState = AppState()
var body: some View {
TabView {
TodayPage().tabItem {
Image(systemName: "info.circle")
Text("Today")
}
CalendarList().tabItem {
Image(systemName: "square.fill.text.grid.1x2")
Text("Calendar")
}
}
.onAppear {
appState.allDays = appState.getDays(number: 365)
}
.environmentObject(appState)
}
}
Then, remove your other onAppear on TodayPage

Custom Segmented Controller SwiftUI Frame Issue

I would like to create a custom segmented controller in SwiftUI, and I found one made from this post. After slightly altering the code and putting it into my ContentView, the colored capsule would not fit correctly.
Here is an example of my desired result:
This is the result when I use it in ContentView:
CustomPicker.swift:
struct CustomPicker: View {
#State var selectedIndex = 0
var titles = ["Item #1", "Item #2", "Item #3", "Item #4"]
private var colors = [Color.red, Color.green, Color.blue, Color.purple]
#State private var frames = Array<CGRect>(repeating: .zero, count: 4)
var body: some View {
VStack {
ZStack {
HStack(spacing: 4) {
ForEach(self.titles.indices, id: \.self) { index in
Button(action: { self.selectedIndex = index }) {
Text(self.titles[index])
.foregroundColor(.black)
.font(.system(size: 16, weight: .medium, design: .default))
.bold()
}.padding(EdgeInsets(top: 16, leading: 16, bottom: 16, trailing: 16)).background(
GeometryReader { geo in
Color.clear.onAppear { self.setFrame(index: index, frame: geo.frame(in: .global)) }
}
)
}
}
.background(
Capsule().fill(
self.colors[self.selectedIndex].opacity(0.4))
.frame(width: self.frames[self.selectedIndex].width,
height: self.frames[self.selectedIndex].height, alignment: .topLeading)
.offset(x: self.frames[self.selectedIndex].minX - self.frames[0].minX)
, alignment: .leading
)
}
.animation(.default)
.background(Capsule().stroke(Color.gray, lineWidth: 3))
}
}
func setFrame(index: Int, frame: CGRect) {
self.frames[index] = frame
}
}
ContentView.swift:
struct ContentView: View {
#State var itemsList = [Item]()
func loadData() {
if let url = Bundle.main.url(forResource: "Data", withExtension: "json") {
do {
let data = try Data(contentsOf: url)
let decoder = JSONDecoder()
let jsonData = try decoder.decode(Response.self, from: data)
for post in jsonData.content {
self.itemsList.append(post)
}
} catch {
print("error:\(error)")
}
}
}
var body: some View {
NavigationView {
VStack {
Text("Item picker")
.font(.system(.title))
.bold()
CustomPicker()
Spacer()
ScrollView {
VStack {
ForEach(itemsList) { item in
ItemView(text: item.text, username: item.username)
.padding(.leading)
}
}
}
.frame(height: UIScreen.screenHeight - 224)
}
.onAppear(perform: loadData)
}
}
}
Project file here
The problem with the code as-written is that the GeometryReader value is only sent on onAppear. That means that if any of the views around it change and the view is re-rendered (like when the data is loaded), those frames will be out-of-date.
I solved this by using a PreferenceKey instead, which will run on each render:
struct CustomPicker: View {
#State var selectedIndex = 0
var titles = ["Item #1", "Item #2", "Item #3", "Item #4"]
private var colors = [Color.red, Color.green, Color.blue, Color.purple]
#State private var frames = Array<CGRect>(repeating: .zero, count: 4)
var body: some View {
VStack {
ZStack {
HStack(spacing: 4) {
ForEach(self.titles.indices, id: \.self) { index in
Button(action: { self.selectedIndex = index }) {
Text(self.titles[index])
.foregroundColor(.black)
.font(.system(size: 16, weight: .medium, design: .default))
.bold()
}
.padding(EdgeInsets(top: 16, leading: 16, bottom: 16, trailing: 16))
.measure() // <-- Here
.onPreferenceChange(FrameKey.self, perform: { value in
self.setFrame(index: index, frame: value) //<-- this will run each time the preference value changes, will will happen any time the frame is updated
})
}
}
.background(
Capsule().fill(
self.colors[self.selectedIndex].opacity(0.4))
.frame(width: self.frames[self.selectedIndex].width,
height: self.frames[self.selectedIndex].height, alignment: .topLeading)
.offset(x: self.frames[self.selectedIndex].minX - self.frames[0].minX)
, alignment: .leading
)
}
.animation(.default)
.background(Capsule().stroke(Color.gray, lineWidth: 3))
}
}
func setFrame(index: Int, frame: CGRect) {
print("Setting frame: \(index): \(frame)")
self.frames[index] = frame
}
}
struct FrameKey : PreferenceKey {
static var defaultValue: CGRect = .zero
static func reduce(value: inout CGRect, nextValue: () -> CGRect) {
value = nextValue()
}
}
extension View {
func measure() -> some View {
self.background(GeometryReader { geometry in
Color.clear
.preference(key: FrameKey.self, value: geometry.frame(in: .global))
})
}
}
Note that the original .background call was taken out and was replaced with .measure() and .onPreferenceChange -- look for where the //<-- Here note is.
Besides that and the PreferenceKey and View extension, nothing else is changed.

How can I use Navigation in alert using SwiftUI

I'm working on a Bluetooth Application.It has onboarding and dashboard.On the Onboarding there is pairing and instructions on how to use the module, and the dashboard controls the peripheral device.So I need to unpair using an alert and navigate it to a different page called Onboarding.How can I navigate to a different view using an alert.
Code Block
import SwiftUI
import BLE
struct Dashboard: View {
#EnvironmentObject var BLE: BLE
#State private var showUnpairAlert: Bool = false
#State private var hasConnected: Bool = false
let defaults = UserDefaults.standard
let defaultDeviceinformation = "01FFFFFFFFFF"
struct Keys {
static let deviceInformation = "deviceInformation"
}
var body: some View {
VStack(alignment: .center, spacing: 0) {
// MARK: - Menu Bar
HStack(alignment: .center, spacing: 10) {
VStack(alignment: .center, spacing: 4) {
Text(self.hasConnected ? "PodId \(checkForDeviceInformation())":"Pod is not connected")
.font(.footnote)
.foregroundColor(.white)
Button(action: {
print("Unpair tapped!")
self.showUnpairAlert = true
}) {
HStack {
Text("Unpair")
.fontWeight(.bold)
.font(.body)
}
.frame(minWidth: 85, minHeight: 35)
.foregroundColor(.white)
.background(Color(red: 0.8784313725490196, green: 0.34509803921568627, blue: 0.36470588235294116))
.cornerRadius(30)
}
}
}
}
.alert(isPresented: $showUnpairAlert) {
Alert(title: Text("Unpair from \(checkForDeviceInformation())"), message: Text("Do you want to unpair the current pod?"), primaryButton: .destructive(Text("Unpair")) {
self.unpairAndSetDefaultDeviceInformation()
}, secondaryButton: .cancel())
}
}
func checkForDeviceInformation() -> String {
let deviceInformation = defaults.value(forKey: Keys.deviceInformation) as? String ?? ""
print("Device Info \(deviceInformation)")
return deviceInformation
}
func unpairAndSetDefaultDeviceInformation() {
defaults.set(defaultDeviceinformation, forKey: Keys.deviceInformation)
print("Pod unpaired and view changed to Onboarding")
}
}
Thank you !!!!
I simplified your code snapshot for demo, but think the idea would be clear
struct TestNavigationFromAlert: View {
#State private var showUnpairAlert: Bool = false
#State private var activateLink: Bool = false
var body: some View {
NavigationView {
VStack {
NavigationLink(destination: Text("Your Onboarding page"), isActive: $activateLink,
label: { EmptyView() })
// DEMO BUTTON - REMOVE IT
Button(action: { self.showUnpairAlert = true }) { Text("Alert") }
// YOUR CODE IS HERE
}
.alert(isPresented: $showUnpairAlert) {
Alert(title: Text("Unpair from \(checkForDeviceInformation())"), message: Text("Do you want to unpair the current pod?"), primaryButton: .destructive(Text("Unpair")) {
self.unpairAndSetDefaultDeviceInformation()
}, secondaryButton: .cancel())
}
}
}
func checkForDeviceInformation() -> String {
// YOUR CODE IS HERE
return "Stub information"
}
func unpairAndSetDefaultDeviceInformation() {
// YOUR CODE IS HERE
DispatchQueue.main.async {
self.activateLink = true
}
}
}