SwiftUI: Switch between List and grid/Collection View - swiftui

Goal: A button that switches between List and Grid/Collection View.
For this, I am using the great WaterfallGrid:
https://github.com/paololeonardi/WaterfallGrid
I haven't managed able to make it work. I am using state, and if statement, as code bellow:
import SwiftUI
import WaterfallGrid
struct Fruit: Identifiable {
let id = UUID()
let name: String
let image: Image
}
struct ExampleView: View {
#State private var fruits = [
Fruit(name: "Apple", image: Image("apple")),
Fruit(name: "Banana", image: Image("banana")),
Fruit(name: "Grapes", image: Image("grapes")),
Fruit(name: "Peach", image: Image("peach"))]
#State private var showgrid = true
var body: some View {
NavigationView {
if showgrid == .true {
return
WaterfallGrid(fruits) { fruit in
HStack {
fruit.image.resizable().frame(width: 30, height: 30)
Text(fruit.name)
}
}
}
else {
return
List(fruits) { fruit in
HStack {
fruit.image.resizable().frame(width: 30, height: 30)
Text(fruit.name)
}
}
}
.navigationBarTitle("Fruits")
.navigationBarItems(trailing:
Button(action: { self.showmaterialrmenu.toggle() }) {
Image(systemName: "rectangle.on.rectangle.angled")
})
}
}
}
struct ExampleView_Previews: PreviewProvider {
static var previews: some View {
ExampleView()
}
}
Really appreciate any help!
Cheers

Hello it's not a good way to put all you views in one place I created one project that need to be having a list and grid mode so here's my implementation:
private enum HomeMode {
case list, grid
func icon() -> String {
switch self {
case .list: return "rectangle.3.offgrid.fill"
case .grid: return "rectangle.grid.1x2"
}
}
}
#State private var homeMode = HomeMode.list
private var swapHomeButton: some View {
Button(action: {
self.homeMode = self.homeMode == .grid ? .list : .grid
}) {
HStack {
Image(systemName: self.homeMode.icon()).imageScale(.medium)
}.frame(width: 30, height: 30)
}
}
and here's my main view:
var body: some View {
let view = Group {
if homeMode == .list {
homeAsList
} else {
homeAsGrid
}
}
.navigationBarItems(trailing:
HStack {
swapHomeButton
settingButton
}
).sheet(isPresented: $isSettingPresented,
content: { SettingsForm() })
return navigationView(content: AnyView(view))
}
HomeList:
private var homeAsList: some View {
Group {
if selectedMenu.menu == .genres {
GenresList(headerView: AnyView(segmentedView))
} else {
MoviesHomeList(menu: $selectedMenu.menu,
pageListener: selectedMenu.pageListener,
headerView: AnyView(segmentedView))
}
}
}
private var homeAsGrid: some View {
MoviesHomeGrid()
}
that's the answer If you are asking about how to arrange the views but if you are asking how to implement the WaterfallGrid hit me back so I can check it and see if we can solve this

Related

Why Timer Change Will Trigger LazyVGrid View Update?

import SwiftUI
struct ContentView: View {
#State private var set = Set<Int>()
#State private var count = "10"
private let columns:[GridItem] = Array(repeating: .init(.flexible()), count: 3)
#State private var timer:Timer? = nil
#State private var time = 0
var body: some View {
VStack {
ScrollView {
LazyVGrid(columns: columns) {
ForEach(Array(set)) { num in
Text(String(num))
}
}
}
.frame(width: 400, height: 400, alignment: .center)
HStack{
TextField("Create \(count) items", text: $count)
Button {
createSet(count: Int(count)!)
} label: {
Text("Create")
}
}
if let _ = timer {
Text(String(time))
.font(.title2)
.foregroundColor(.green)
}
HStack {
Button {
time = 100
let timer = Timer.scheduledTimer(withTimeInterval: 10, repeats: true) { _ in
time -= 10
if time == 0 {
self.timer?.invalidate()
self.timer = nil
}
}
self.timer = timer
} label: {
Text("Start Timer")
}
Button {
self.timer?.invalidate()
self.timer = nil
} label: {
Text("Stop Timer")
}
}
}
.padding()
}
private func createSet(count:Int) {
set.removeAll(keepingCapacity: true)
repeat {
let num = Int.random(in: 1...10000)
set.insert(num)
} while set.count < count
}
}
extension Int:Identifiable {
public var id:Self { self }
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
I made a break point on Text(String(num)). Every time the timer was trigger, the GridView updated. Why this happened? As the model of grid didn't change.
Updated
If I put the timer in another view, the grid view wouldn't be trigger.
import SwiftUI
struct ContentView: View {
#State private var set = Set<Int>()
#State private var count = "10"
private let columns:[GridItem] = Array(repeating: .init(.flexible()), count: 3)
var body: some View {
VStack {
ScrollView {
LazyVGrid(columns: columns) {
ForEach(Array(set)) { num in
Text(String(num))
}
}
}
.frame(width: 400, height: 400, alignment: .center)
HStack{
TextField("Create \(count) items", text: $count)
Button {
createSet(count: Int(count)!)
} label: {
Text("Create")
}
}
TimerView()
}
.padding()
}
private func createSet(count:Int) {
set.removeAll(keepingCapacity: true)
repeat {
let num = Int.random(in: 1...10000)
set.insert(num)
} while set.count < count
}
}
extension Int:Identifiable {
public var id:Self { self }
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
import SwiftUI
struct TimerView: View {
#State private var timer:Timer? = nil
#State private var time = 0
var body: some View {
if let _ = timer {
Text(String(time))
.font(.title2)
.foregroundColor(.green)
}
HStack {
Button {
time = 100
let timer = Timer.scheduledTimer(withTimeInterval: 10, repeats: true) { _ in
time -= 10
if time == 0 {
self.timer?.invalidate()
self.timer = nil
}
}
self.timer = timer
} label: {
Text("Start Timer")
}
Button {
self.timer?.invalidate()
self.timer = nil
} label: {
Text("Stop Timer")
}
}
}
}
struct TimerView_Previews: PreviewProvider {
static var previews: some View {
TimerView()
}
}
That´s pretty much how SwiftUI works. Every change to a #State var triggers the View to reevaluate. If you put your ForEach in another view it will only reevaluate if you change a var that changes that view. E.g. set or columns.
struct ExtractedView: View {
var columns: [GridItem]
var set: Set<Int>
var body: some View {
ScrollView {
LazyVGrid(columns: columns) {
ForEach(Array(set)) { num in
Text(String(num))
}
}
}
.frame(width: 400, height: 400, alignment: .center)
}
}
It is encouraged in SwiftUI to make many small Views. The system driving this is pretty good in identifying what needs to be changed and what not. There is a very good WWDC video describing this.
WWDC

Published/Observed var not updating in view swiftui w/ called function

Struggling to get a simple example up and running in swiftui:
Load default list view (working)
click button that launches picker/filtering options (working)
select options, then click button to dismiss and call function with selected options (call is working)
display new list of objects returned from call (not working)
I'm stuck on #4 where the returned query isn't making it to the view. I suspect I'm creating a different instance when making the call in step #3 but it's not making sense to me where/how/why that matters.
I tried to simplify the code some, but it's still a bit, sorry for that.
Appreciate any help!
Main View with HStack and button to filter with:
import SwiftUI
import FirebaseFirestore
struct TestView: View {
#ObservedObject var query = Query()
#State var showMonPicker = false
#State var monFilter = "filter"
var body: some View {
VStack {
HStack(alignment: .center) {
Text("Monday")
Spacer()
Button(action: {
self.showMonPicker.toggle()
}, label: {
Text("\(monFilter)")
})
}
.padding()
ScrollView(.horizontal) {
LazyHStack(spacing: 35) {
ForEach(query.queriedList) { menuItems in
MenuItemView(menuItem: menuItems)
}
}
}
}
.sheet(isPresented: $showMonPicker, onDismiss: {
//optional function when picker dismissed
}, content: {
CuisineTypePicker(selectedCuisineType: $monFilter)
})
}
}
The Query() file that calls a base query with all results, and optional function to return specific results:
import Foundation
import FirebaseFirestore
class Query: ObservableObject {
#Published var queriedList: [MenuItem] = []
init() {
baseQuery()
}
func baseQuery() {
let queryRef = Firestore.firestore().collection("menuItems").limit(to: 50)
queryRef
.getDocuments() { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
} else {
self.queriedList = querySnapshot?.documents.compactMap { document in
try? document.data(as: MenuItem.self)
} ?? []
}
}
}
func filteredQuery(category: String?, glutenFree: Bool?) {
var filtered = Firestore.firestore().collection("menuItems").limit(to: 50)
// Sorting and Filtering Data
if let category = category, !category.isEmpty {
filtered = filtered.whereField("cuisineType", isEqualTo: category)
}
if let glutenFree = glutenFree, !glutenFree {
filtered = filtered.whereField("glutenFree", isEqualTo: true)
}
filtered
.getDocuments() { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
} else {
self.queriedList = querySnapshot?.documents.compactMap { document in
try? document.data(as: MenuItem.self);
} ?? []
print(self.queriedList.count)
}
}
}
}
Picker view where I'm calling the filtered query:
import SwiftUI
struct CuisineTypePicker: View {
#State private var cuisineTypes = ["filter", "American", "Chinese", "French"]
#Environment(\.presentationMode) var presentationMode
#Binding var selectedCuisineType: String
#State var gfSelected = false
let query = Query()
var body: some View {
VStack(alignment: .center) {
//Buttons and formatting code removed to simplify..
}
.padding(.top)
Picker("", selection: $selectedCuisineType) {
ForEach(cuisineTypes, id: \.self) {
Text($0)
}
}
Spacer()
Button(action: {
self.query.filteredQuery(category: selectedCuisineType, glutenFree: gfSelected)
self.presentationMode.wrappedValue.dismiss()
}, label: {
Text( "apply filters")
})
}
.padding()
}
}
I suspect that the issue stems from the fact that you aren't sharing the same instance of Query between your TestView and your CuisineTypePicker. So, when you start a new Firebase query on the instance contained in CuisineTypePicker, the results are never reflected in the main view.
Here's an example of how to solve that (with the Firebase code replaced with some non-asynchronous sample code for now):
struct MenuItem : Identifiable {
var id = UUID()
var cuisineType : String
var title : String
var glutenFree : Bool
}
struct ContentView: View {
#ObservedObject var query = Query()
#State var showMonPicker = false
#State var monFilter = "filter"
var body: some View {
VStack {
HStack(alignment: .center) {
Text("Monday")
Spacer()
Button(action: {
self.showMonPicker.toggle()
}, label: {
Text("\(monFilter)")
})
}
.padding()
ScrollView(.horizontal) {
LazyHStack(spacing: 35) {
ForEach(query.queriedList) { menuItem in
Text("\(menuItem.title) - \(menuItem.cuisineType)")
}
}
}
}
.sheet(isPresented: $showMonPicker, onDismiss: {
//optional function when picker dismissed
}, content: {
CuisineTypePicker(query: query, selectedCuisineType: $monFilter)
})
}
}
class Query: ObservableObject {
#Published var queriedList: [MenuItem] = []
private let allItems: [MenuItem] = [.init(cuisineType: "American", title: "Hamburger", glutenFree: false),.init(cuisineType: "Chinese", title: "Fried Rice", glutenFree: true)]
init() {
baseQuery()
}
func baseQuery() {
self.queriedList = allItems
}
func filteredQuery(category: String?, glutenFree: Bool?) {
queriedList = allItems.filter({ item in
if let category = category {
return item.cuisineType == category
} else {
return true
}
}).filter({item in
if let glutenFree = glutenFree {
return item.glutenFree == glutenFree
} else {
return true
}
})
}
}
struct CuisineTypePicker: View {
#ObservedObject var query : Query
#Binding var selectedCuisineType: String
#State private var gfSelected = false
private let cuisineTypes = ["filter", "American", "Chinese", "French"]
#Environment(\.presentationMode) private var presentationMode
var body: some View {
VStack(alignment: .center) {
//Buttons and formatting code removed to simplify..
}
.padding(.top)
Picker("", selection: $selectedCuisineType) {
ForEach(cuisineTypes, id: \.self) {
Text($0)
}
}
Spacer()
Button(action: {
self.query.filteredQuery(category: selectedCuisineType, glutenFree: gfSelected)
self.presentationMode.wrappedValue.dismiss()
}, label: {
Text( "apply filters")
})
}
}

How to Add multi text into the list in SwiftUI?(Data Flow)

I'm trying to build an demo app by swiftUI that get multi text from user and add them to the list, below , there is an image of app every time user press plus button the AddListView show to the user and there user can add multi text to the List.I have a problem to add them to the list by new switUI data Flow I don't know how to pass data.(I comment more information)
Thanks 🙏
here is my code for AddListView:
import SwiftUI
struct AddListView: View {
#State var numberOfTextFiled = 1
#Binding var showAddListView : Bool
var body: some View {
ZStack {
Title(numberOfTextFiled: $numberOfTextFiled)
VStack {
ScrollView {
ForEach(0 ..< numberOfTextFiled, id: \.self) { item in
PreAddTextField()
}
}
}
.padding()
.offset(y: 40)
Buttons(showAddListView: $showAddListView)
}
.frame(width: 300, height: 200)
.background(Color.white)
.shadow(color: Color.black.opacity(0.3), radius: 10, x: 0, y: 10)
}
}
struct SwiftUIView_Previews: PreviewProvider {
static var previews: some View {
AddListView(showAddListView: .constant(false))
}
}
struct PreAddTextField: View {
// I made this standalone struct and use #State to every TextField text be independent
// if i use #Binding to pass data all Texfield have the same text value
#State var textInTextField = ""
var body: some View {
VStack {
TextField("Enter text", text: $textInTextField)
}
}
}
struct Buttons: View {
#Binding var showAddListView : Bool
var body: some View {
VStack {
HStack(spacing:100) {
Button(action: {
showAddListView = false}) {
Text("Cancel")
}
Button(action: {
showAddListView = false
// What should happen here to add Text to List???
}) {
Text("Add")
}
}
}
.offset(y: 70)
}
}
struct Title: View {
#Binding var numberOfTextFiled : Int
var body: some View {
VStack {
HStack {
Text("Add Text to list")
.font(.title2)
Spacer()
Button(action: {
numberOfTextFiled += 1
}) {
Image(systemName: "plus")
.font(.title2)
}
}
.padding()
Spacer()
}
}
}
and for DataModel:
import SwiftUI
struct Text1 : Identifiable , Hashable{
var id = UUID()
var text : String
}
var textData = [
Text1(text: "SwiftUI"),
Text1(text: "Data flow?"),
]
and finally:
import SwiftUI
struct ListView: View {
#State var showAddListView = false
var body: some View {
NavigationView {
VStack {
ZStack {
List(textData, id : \.self){ text in
Text(text.text)
}
if showAddListView {
AddListView(showAddListView: $showAddListView)
.offset(y:-100)
}
}
}
.navigationTitle("List")
.navigationBarItems(trailing:
Button(action: {showAddListView = true}) {
Image(systemName: "plus")
.font(.title2)
}
)
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ListView()
}
}
Because of the multiple-items part of the question, this becomes a lot less trivial. However, using a combination of ObservableObjects and callback functions, definitely doable. Look at the inline comments in the code for explanations about what is going on:
struct Text1 : Identifiable , Hashable{
var id = UUID()
var text : String
}
//Store the items in an ObservableObject instead of just in #State
class AppState : ObservableObject {
#Published var textData : [Text1] = [.init(text: "Item 1"),.init(text: "Item 2")]
}
//This view model stores data about all of the new items that are going to be added
class AddListViewViewModel : ObservableObject {
#Published var textItemsToAdd : [Text1] = [.init(text: "")] //start with one empty item
//save all of the new items -- don't save anything that is empty
func saveToAppState(appState: AppState) {
appState.textData.append(contentsOf: textItemsToAdd.filter { !$0.text.isEmpty })
}
//these Bindings get used for the TextFields -- they're attached to the item IDs
func bindingForId(id: UUID) -> Binding<String> {
.init { () -> String in
self.textItemsToAdd.first(where: { $0.id == id })?.text ?? ""
} set: { (newValue) in
self.textItemsToAdd = self.textItemsToAdd.map {
guard $0.id == id else {
return $0
}
return .init(id: id, text: newValue)
}
}
}
}
struct AddListView: View {
#Binding var showAddListView : Bool
#ObservedObject var appState : AppState
#StateObject private var viewModel = AddListViewViewModel()
var body: some View {
ZStack {
Title(addItem: { viewModel.textItemsToAdd.append(.init(text: "")) })
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 //this takes a binding to the view model now
var body: some View {
VStack {
TextField("Enter text", text: $textInTextField)
}
}
}
struct Buttons: View {
#Binding var showAddListView : Bool
var save : () -> Void //callback function for what happens when "Add" gets pressed
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 //callback function for what happens when the plus button is hit
var body: some View {
VStack {
HStack {
Text("Add Text to list")
.font(.title2)
Spacer()
Button(action: {
addItem()
}) {
Image(systemName: "plus")
.font(.title2)
}
}
.padding()
Spacer()
}
}
}
struct ListView: View {
#StateObject var appState = AppState() //store the AppState here
#State private var showAddListView = false
var body: some View {
NavigationView {
VStack {
ZStack {
List(appState.textData, id : \.self){ text in
Text(text.text)
}
if showAddListView {
AddListView(showAddListView: $showAddListView, appState: appState)
.offset(y:-100)
}
}
}
.navigationTitle("List")
.navigationBarItems(trailing:
Button(action: {showAddListView = true}) {
Image(systemName: "plus")
.font(.title2)
}
)
}
}
}

Any ideas how to help this Form + ForEach SwiftUI view update it’s NavigationLink Destination?

I’m seeing this issue where a Form / NavigationLink set up seems to stop passing through the data on changes.
Expected behavior: Checkmarks should update when you pick a different food.
Observed behavior: You can see the favorite food changing outside the NavigationLink Destination, but not inside.
This setup mirrors a dynamic application where a ForEach is used to display various NavigationLinks in the Form based on parent data. Weirdly enough, this works if you replace Form with VStack, so I’m curious why this isn’t updating.
I have attached two minimum-setup example projects that replicate this issue where the destination of a NavigationLink is not receiving an update when data is changing. One with Binding, one with simpler passed properties.
Sample Project #1 with Binding - Dropbox
Sample Project #2 without Binding - Dropbox
Code #1:
//
// ContentView.swift
// Form Updating Example
//
// Created by Sahand Nayebaziz on 12/10/20.
//
import SwiftUI
struct ContentView: View {
#State var isPresentingMainView = false
#State var favoriteFood: FoodType = .bagel
var body: some View {
VStack {
Button(action: { isPresentingMainView = true }, label: {
Text("Present Main View")
})
}
.fullScreenCover(isPresented: $isPresentingMainView) {
MainView(favoriteFood: $favoriteFood)
}
}
}
struct MainView: View {
#Binding var favoriteFood: FoodType
var body: some View {
NavigationView {
HStack {
Spacer()
Text(favoriteFood.emoji)
.font(.title)
.foregroundColor(.secondary)
Spacer()
NavigationView {
Form {
List {
ForEach(["SomethingRepresentingShowingFood"], id: \.self) { _ in
NavigationLink(
destination: makeDetail(),
label: {
Text("Food Randomizer")
})
}
}
}
}
.navigationViewStyle(StackNavigationViewStyle())
.frame(maxWidth: 350)
}
.navigationTitle("Main")
.navigationBarTitleDisplayMode(.inline)
}
.navigationViewStyle(StackNavigationViewStyle())
}
func makeDetail() -> some View {
Form {
ForEach(FoodType.allCases) { foodType in
Button(action: { favoriteFood = foodType }, label: {
HStack {
Text(foodType.emoji)
Spacer()
if favoriteFood == foodType {
Image(systemName: "checkmark")
}
}
})
}
}
}
}
enum FoodType: String, Identifiable, CaseIterable {
case bagel, pizza, broccoli
var id: String { rawValue }
var emoji: String {
switch self {
case .bagel: return "🥯"
case .pizza: return "🍕"
case .broccoli: return "🥦"
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
Group {
ContentView()
MainView(favoriteFood: .constant(.bagel))
MainView(favoriteFood: .constant(.bagel))
.makeDetail()
}
}
}
Code #2:
//
// ContentView.swift
// Form Updating Example
//
// Created by Sahand Nayebaziz on 12/10/20.
//
import SwiftUI
struct ContentView: View {
#State var isPresentingMainView = false
#State var favoriteFood: FoodType = .bagel
var body: some View {
VStack {
Button(action: { isPresentingMainView = true }, label: {
Text("Present Main View")
})
}
.fullScreenCover(isPresented: $isPresentingMainView) {
MainView(currentFavoriteFood: favoriteFood, onUpdateFavoriteFood: { favoriteFood = $0 })
}
}
}
struct MainView: View {
let currentFavoriteFood: FoodType
let onUpdateFavoriteFood: (FoodType) -> Void
var body: some View {
NavigationView {
HStack {
Spacer()
Text(currentFavoriteFood.emoji)
.font(.title)
.foregroundColor(.secondary)
Spacer()
NavigationView {
Form {
List {
ForEach(["SomethingRepresentingShowingFood"], id: \.self) { _ in
NavigationLink(
destination: makeDetail(),
label: {
Text("Food Randomizer")
})
}
}
}
}
.navigationViewStyle(StackNavigationViewStyle())
.frame(maxWidth: 350)
}
.navigationTitle("Main")
.navigationBarTitleDisplayMode(.inline)
}
.navigationViewStyle(StackNavigationViewStyle())
}
func makeDetail() -> some View {
Form {
ForEach(FoodType.allCases) { foodType in
Button(action: { onUpdateFavoriteFood(foodType) }, label: {
HStack {
Text(foodType.emoji)
Spacer()
if currentFavoriteFood == foodType {
Image(systemName: "checkmark")
}
}
})
}
}
}
}
enum FoodType: String, Identifiable, CaseIterable {
case bagel, pizza, broccoli
var id: String { rawValue }
var emoji: String {
switch self {
case .bagel: return "🥯"
case .pizza: return "🍕"
case .broccoli: return "🥦"
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
Group {
ContentView()
MainView(currentFavoriteFood: .bagel, onUpdateFavoriteFood: { _ in })
MainView(currentFavoriteFood: .bagel, onUpdateFavoriteFood: { _ in })
.makeDetail()
}
}
}

How to delete multiple rows from List in SwiftUI?

I took an example from this question: How does one enable selections in SwiftUI's List and edited the code to be able to delete rows one by one. But I don't know how to delete multiple rows from list.
Could you help me, please?
var demoData = ["Phil Swanson", "Karen Gibbons", "Grant Kilman", "Wanda Green"]
struct ContentView : View {
#State var selectKeeper = Set<String>()
var body: some View {
NavigationView {
List(selection: $selectKeeper){
ForEach(demoData, id: \.self) { name in
Text(name)
}
.onDelete(perform: delete)
}
.navigationBarItems(trailing: EditButton())
.navigationBarTitle(Text("Selection Demo \(selectKeeper.count)"))
}
}
func delete(at offsets: IndexSet) {
demoData.remove(atOffsets: offsets)
}
}
solution from SwiftUI how to perform action when EditMode changes?
struct Item: Identifiable {
let id = UUID()
let title: String
static var i = 0
init() {
self.title = "\(Item.i)"
Item.i += 1
}
}
struct ContentView: View {
#State var editMode: EditMode = .inactive
#State var selection = Set<UUID>()
#State var items = [Item(), Item(), Item()]
var body: some View {
NavigationView {
List(selection: $selection) {
ForEach(items) { item in
Text(item.title)
}
}
.navigationBarTitle(Text("Demo"))
.navigationBarItems(
leading: editButton,
trailing: addDelButton
)
.environment(\.editMode, self.$editMode)
}
}
private var editButton: some View {
Button(action: {
self.editMode.toggle()
self.selection = Set<UUID>()
}) {
Text(self.editMode.title)
}
}
private var addDelButton: some View {
if editMode == .inactive {
return Button(action: addItem) {
Image(systemName: "plus")
}
} else {
return Button(action: deleteItems) {
Image(systemName: "trash")
}
}
}
private func addItem() {
items.append(Item())
}
private func deleteItems() {
for id in selection {
if let index = items.lastIndex(where: { $0.id == id }) {
items.remove(at: index)
}
}
selection = Set<UUID>()
}
}
extension EditMode {
var title: String {
self == .active ? "Done" : "Edit"
}
mutating func toggle() {
self = self == .active ? .inactive : .active
}
}