I am creating single selection list to use in different places in my app.
Questions:
Is there an easy solution I don't know?
If there isn't, how can I finish my current solution?
My goal:
- List with always only one item selected or one or none item selected (depending on configuration)
- Transparent background
- On item select - perform action which is set as parameter via init() method. (That action requires selected item info.)
- Change list data programmatically and reset selection to first item
My current solution looks like: List view with second item selected
I can't use Picker, because outer action (goal Nr. 3) is time consuming. So I think it wouldn't work smoothly. Most probably there is solution to my problem in SwiftUI, but either I missed it, because I am new to swift or as I understand not everything works perfectly in SwiftUI yet, for example: transparent background for List (which is why i needed to clear background in init()).
So I started implementing selection myself, and stoped here: My current solution does not update view when item(Button) is clicked. (Only going out and back to the page updates view). And still multiple items can be selected.
import SwiftUI
struct ModuleList: View {
var modules: [Module] = []
@Binding var selectionKeeper: Int
var Action: () -> Void
init(list: [Module], selection: Binding<Int>, action: @escaping () -> Void) {
UITableView.appearance().backgroundColor = .clear
self.modules = list
self._selectionKeeper = selection
self.Action = action
}
var body: some View {
List(){
ForEach(0..<modules.count) { i in
ModuleCell(module: self.modules[i], action: { self.changeSelection(index: i) })
}
}.background(Constants.colorTransparent)
}
func changeSelection(index: Int){
modules[selectionKeeper].isSelected = false
modules[index].isSelected = true
selectionKeeper = index
self.Action()
}
}
struct ModuleCell: View {
var module: Module
var Action: () -> Void
init(module: Module, action: @escaping () -> Void) {
UITableViewCell.appearance().backgroundColor = .clear
self.module = module
self.Action = action
}
var body: some View {
Button(module.name, action: {
self.Action()
})
.frame(minWidth: 0, maxWidth: .infinity, alignment: .center)
.modifier(Constants.CellSelection(isSelected: module.isSelected))
}
}
class Module: Identifiable {
var id = UUID()
var name: String = ""
var isSelected: Bool = false
var address: Int
init(name: String, address: Int){
self.name = name
self.address = address
}
}
let testLines = [
Module(name: "Line1", address: 1),
Module(name: "Line2", address: 3),
Module(name: "Line3", address: 5),
Module(name: "Line4", address: 6),
Module(name: "Line5", address: 7),
Module(name: "Line6", address: 8),
Module(name: "Line7", address: 12),
Module(name: "Line8", address: 14),
Module(name: "Line9", address: 11),
Module(name: "Line10", address: 9),
Module(name: "Line11", address: 22)
]
Testing some ideas:
Tried adding @State array of (isSelected: Bool) in ModuleList and binding it to Module isSelected parameter that MIGHT update view... But failed then populating this array in init(), because @State array parameter would stay empty after .append()... Maybe adding function setList would have solved this, and my goal Nr. 4. But I was not sure if this would really update my view in the first place.
struct ModuleList: View {
var modules: [Module] = []
@State var selections: [Bool] = []
init(list: [String]) {
UITableView.appearance().backgroundColor = .clear
selections = [Bool] (repeating: false, count: list.count) // stays empty
let test = [Bool] (repeating: false, count: list.count) // testing: works as it should
selections = test
for i in 0..<test.count { // for i in 0..<selections.count {
selections.append(false)
modules.append(Module(name: list[i], isSelected: $selections[i])) // Error selections is empty
}
}
var body: some View {
List{
ForEach(0..<modules.count) { i in
ModuleCell(module: self.modules[i], action: { self.changeSelection(index: i) })
}
}.background(Constants.colorTransparent)
}
func changeSelection(index: Int){
modules[index].isSelected = true
}
}
struct ModuleCell: View {
var module: Module
var Method: () -> Void
init(module: Module, action: @escaping () -> Void) {
UITableViewCell.appearance().backgroundColor = .clear
self.module = module
self.Method = action
}
var body: some View {
Button(module.name, action: {
self.Method()
})
.frame(minWidth: 0, maxWidth: .infinity, alignment: .center)
.modifier(Constants.CellSelection(isSelected: module.isSelected))
}
}
struct Module: Identifiable {
var id = UUID()
var name: String = ""
@Binding var isSelected: Bool
init(name: String, isSelected: Binding<Bool>){
self.name = name
self._isSelected = isSelected
}
}
let testLines = ["Line1","Line2","Line3","Line4"
]
